[PATCH net v2 0/6] net: stmmac: More selftest-related fixes

[PATCH net v2 0/6] net: stmmac: More selftest-related fixes

[Maxime Chevallier]

Hi everyone,

Here's V2 of the stmmac selftest fixes. I don't really know why but V1
was only partially delivered, yet Nicolai was kind enough to review
whatever managed to get to the lists, and found some things to improve
in the EEE test, addressed in this new iteration :) Hence, this is V2
and not a resend.

This is another round of stmmac selftest fixes, mostly about the selftests
themselves but a few things were discovered w.r.t MTU and buffer size
handling, see patch 5.

I've continued expanding the test devices I'm running this on, more devices
should come in the future. With this series, _almost_ everything is
green, except for some flow control stuff that is either a false positive
or a real thing that needs investigating.

After this is merged, I consider the selftests to be now reliable enough
to run them nightly on every stmmac series that's sent, and I'll be requiring
clean selftests for new glue drivers.

I've been running this on :

 - Altera CycloneV (dwmac-socfpga, dwmac1000 IP, v3.70a)
 - NXP imx8mp (dwmac-imx, dwmac4, v5.10a)
 - Allwinner H2S (dwmac-sun8i, dwmac1000)
 - Amlogic S905X3 (dwmac-meson8b, dwmac1000, v3.70a)
 - STM32mp157a (dwmac-stm32, dwmac4, v4.20a)
 - SiFive JH7110 (dwmac-starfive, dwmac4, v5.20)
 - Motorcomm YT8061 (PCIe, dwmac-motorcomm, dwmac4)
 - Qualcomm IPQ8064 (dwmac-ipq806x, dwmac1000)

Tests are OK if return is 0 or -95 (-EOPNOTSUPP), tests are KO otherwise

Before the series :

Test                     imx  socfpga sun8i meson8b stm32 starV mcom ipq806x
MAC Loopback              0     0      0     0       0     0     0    -110
MMC Counters              0     0      -95   0       0     0     0    -110
EEE                       -95   -95    -95   -110    -110  -95   -95  -95
Hash Filter MC            0     0      -95   0       0     0     0    -95
Perfect Filter UC         -95   0      0     -95     -95   -95   -95  -95
MC Filter                 -95   0      -95   -95     -95   -95   -95  -95
UC Filter                 -95   0      -95   -95     -95   -95   -95  -95
Flow Control              -95   0      -110  0       -110  -95   -110 -110
RSS                       -95   -95    -95   -95     -95   -95   -95  -95
VLAN Filtering            -110  -95    -95   -95     -110  -110  -95  -95
VLAN Filtering (perf)     -110  -95    -95   -95     -110  -110  -95  -95
Double VLAN Filter        -110  -95    -95   -95     -110  -110  -95  -95
Double VLAN Filter (perf) -110  -95    -95   -95     -110  -110  -95  -95
Flexible RX Parser        0     -95    -95   -95     -95   -95   -95  -95
SA Insertion (desc)       0     -95    -95   -95     0     0     0    -95
SA Replacement (desc)     0     -95    -95   -95     0     0     0    -95
SA Insertion (reg         0     -95    -95   -95     0     0     0    -95
SA Replacement (reg)      0     -95    -95   -95     0     0     0    -95
VLAN TX Insertion         -110  -95    -95   -95     -110  -110  -110 -95
SVLAN TX Insertion        -110  -95    -95   -95     -110  -95   -110 -95
L3 DA Filtering           0     -95    -95   -95     -95   -95   -95  -95
L3 SA Filtering           0     -95    -95   -95     -95   -95   -95  -95
L4 DA TCP Filtering       0     -95    -95   -95     -95   -95   -95  -95
L4 SA TCP Filtering       0     -95    -95   -95     -95   -95   -95  -95
L4 DA UDP Filtering       0     -95    -95   -95     -95   -95   -95  -95
L4 SA UDP Filtering       0     -95    -95   -95     -95   -95   -95  -95
ARP Offload               -95   -95    -95   -95     -110  -110  -110 -95
Jumbo Frame               0     -110   -110  0       0     0     0    -110
Multichannel Jumbo        0     -95    -95   -95     -95   -95   -95  -95
Split Header             --95   -95    -95   -95     -95   -95   0    -95
TBS (ETF Scheduler)      --95   -95    -95   -95     -95   -95   -95  -95

ARP offload's still there as this was a net-next patch and I've ran these
checks on the net tree.

Jumbo frame tests on dwmac1000 started failing after :

commit 23680bf5f8c6 ("net: stmmac: restore NET_IP_ALIGN in the RX DMA offset")

This commit is OK though, it just made the selftest reveal the cracks
hiding beneath the surface of MTU/bufsz handling.

After this series :

Test                     imx  socfpga sun8i meson8b stm32 starV mcom ipq806x
MAC Loopback              0      0     0       0     0     0     0    0
MMC Counters              0      0     -95     0     0     0     0    0
EEE                       -95    -95   -95     0     0     -95   -95  -95
Hash Filter MC            0      0     -95     0     0     0     0    -95
Perfect Filter UC         -95    0     0       -95   -95   -95   -95  -95
MC Filter                 -95    0     -95     -95   -95   -95   -95  -95
UC Filter                 -95    0     -95     -95   -95   -95   -95  -95
Flow Control              -95    0     -110    0     -110  -95   -110 -110
RSS                       -95    -95   -95     -95   -95   -95   -95  -95
VLAN Filtering            0      -95   -95     -95   0     0     -95  -95
VLAN Filtering (perf)     0      -95   -95     -95   0     0     -95  -95
Double VLAN Filter        0      -95   -95     -95   0     0     -95  -95
Double VLAN Filter (perf) 0      -95   -95     -95   0     0     -95  -95
Flexible RX Parser        0      -95   -95     -95   -95   -95   -95  -95
SA Insertion (desc)       0      -95   -95     -95   0     0     0    -95
SA Replacement (desc)     0      -95   -95     -95   0     0     0    -95
SA Insertion (reg         0      -95   -95     -95   0     0     0    -95
SA Replacement (reg)      0      -95   -95     -95   0     0     0    -95
VLAN TX Insertion         0      -95   -95     -95   0     0     0    -95
SVLAN TX Insertion        -95    -95   -95     -95   -95   -95   -95  -95
L3 DA Filtering           0      -95   -95     -95   -95   -95   -95  -95
L3 SA Filtering           0      -95   -95     -95   -95   -95   -95  -95
L4 DA TCP Filtering       0      -95   -95     -95   -95   -95   -95  -95
L4 SA TCP Filtering       0      -95   -95     -95   -95   -95   -95  -95
L4 DA UDP Filtering       0      -95   -95     -95   -95   -95   -95  -95
L4 SA UDP Filtering       0      -95   -95     -95   -95   -95   -95  -95
ARP Offload               -95    -95   -95     -95   -110  -110  -110 -95
Jumbo Frame               0      0     0       0     0     0     0    0
Multichannel Jumbo        0      -95   -95     -95   -95   -95   -95  -95
Split Header              -95    -95   -95     -95   -95   -95   0    -95
TBS (ETF Scheduler)       -95    -95   -95     -95   -95   -95   -95  -95

ARP can be ignored, and Flow control needs some more attention, but
we're getting there :)

Thanks,

Maxime

V2:
 - Snapshot before sending the frame for EEE, in case we immediately
   enter LPI
 - Also return -ETIMEDOUT instead of EINVAL

V1: https://lore.kernel.org/lkml/20260909074740.1247762-1-maxime.chevallier@bootlin.com/

Maxime Chevallier (6):
  net: stmmac: selftests: Support running selftests on DSA conduits
  net: stmmac: selftests: Validate EEE based on the actual LPI timer
    value
  net: stmmac: selftests: Check the dev->features for S-TAG offload
    testing
  net: stmmac: selftests: Capture all packets for vlan checks
  net: stmmac: size the RX buffers from the frame length, not the MTU
  net: stmmac: selftests: Account for alignment shift on dwmac1000 for
    Jumbo test

 .../net/ethernet/stmicro/stmmac/stmmac_main.c |  20 +--
 .../stmicro/stmmac/stmmac_selftests.c         | 116 +++++++++++++++---
 2 files changed, 109 insertions(+), 27 deletions(-)

-- 
2.55.0

[PATCH net v2 1/6] net: stmmac: selftests: Support running selftests on DSA conduits

[Maxime Chevallier]

Most stmmac selftests rely on dev_add_pack() to add custom handlers,
that validate the packets sent to ourselves through MAC loopback.

However, when the stmmac-driven interface is a DSA CPU conduit, all
frames that are received have ETH_P_XDSA as a protocol, even though they
don't actually contain any tag as they come from the loopback and not
the switch.

This will prevent any incoming packet to match our packet handlers.

Let's register a ETH_P_ALL packet handler when we detect that we're a
DSA conduit, and use a proxy packet handler to filter the h_proto.

Note that we may still receive incoming packets from the switch, but
these frames shouldn't interfere with the very specific frames used for
selftests, and stmmac selftests in general aren't safe against external
traffic interferences.

This was validated on a WPQ864 devkit for IPQ8064, that has the SoC
connected to a QCA8k switch.

The ARP offload's packet handler is left alone, this feature is just not
implemented in stmmac and due for removal.

Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 .../stmicro/stmmac/stmmac_selftests.c         | 68 ++++++++++++++++---
 1 file changed, 58 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
index 6372ec7c3f31..6503678b646e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
@@ -12,6 +12,7 @@
 #include <linux/ethtool.h>
 #include <linux/ip.h>
 #include <linux/udp.h>
+#include <net/dsa.h>
 #include <net/pkt_cls.h>
 #include <net/pkt_sched.h>
 #include <net/tcp.h>
@@ -237,6 +238,9 @@ struct stmmac_test_priv {
 	struct stmmac_packet_attrs *packet;
 	struct packet_type pt;
 	struct completion comp;
+	__be16 packet_type;
+	int (*func)(struct sk_buff *skb, struct net_device *ndev,
+		    struct packet_type *pt, struct net_device *orig_ndev);
 	int double_vlan;
 	int vlan_id;
 	int ok;
@@ -316,6 +320,50 @@ static int stmmac_test_loopback_validate(struct sk_buff *skb,
 	return 0;
 }
 
+static int stmmac_sft_filter(struct sk_buff *skb, struct net_device *ndev,
+			     struct packet_type *pt,
+			     struct net_device *orig_ndev)
+{
+	struct stmmac_test_priv *tpriv = pt->af_packet_priv;
+	struct ethhdr *hdr = eth_hdr(skb);
+	int ret = 0;
+
+	if (hdr->h_proto == tpriv->packet_type) {
+		struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
+
+		if (nskb)
+			ret = tpriv->func(nskb, ndev, pt, orig_ndev);
+	}
+
+	kfree_skb(skb);
+	return ret;
+}
+
+static void stmmac_sft_add_pack(struct packet_type *pt)
+{
+	struct stmmac_test_priv *tpriv = pt->af_packet_priv;
+
+	if (netdev_uses_dsa(tpriv->pt.dev)) {
+		tpriv->packet_type = tpriv->pt.type;
+		tpriv->func = tpriv->pt.func;
+
+		/* DSA conduit will report ETH_P_XDSA, so our packet handler
+		 * won't match. Let's register a ETH_P_ALL match and filter
+		 * manually in stmmac_sft_filter.
+		 */
+		tpriv->pt.type = htons(ETH_P_ALL);
+		tpriv->pt.func = stmmac_sft_filter;
+		tpriv->pt.ignore_outgoing = true;
+	}
+
+	dev_add_pack(pt);
+}
+
+static void stmmac_sft_remove_pack(struct packet_type *pt)
+{
+	dev_remove_pack(pt);
+}
+
 static int __stmmac_test_loopback(struct stmmac_priv *priv,
 				  struct stmmac_packet_attrs *attr)
 {
@@ -337,7 +385,7 @@ static int __stmmac_test_loopback(struct stmmac_priv *priv,
 	tpriv->packet = attr;
 
 	if (!attr->dont_wait)
-		dev_add_pack(&tpriv->pt);
+		stmmac_sft_add_pack(&tpriv->pt);
 
 	skb = stmmac_test_get_udp_skb(priv, attr);
 	if (!skb) {
@@ -360,7 +408,7 @@ static int __stmmac_test_loopback(struct stmmac_priv *priv,
 
 cleanup:
 	if (!attr->dont_wait)
-		dev_remove_pack(&tpriv->pt);
+		stmmac_sft_remove_pack(&tpriv->pt);
 	kfree(tpriv);
 	return ret;
 }
@@ -767,7 +815,7 @@ static int stmmac_test_flowctrl(struct stmmac_priv *priv)
 	tpriv->pt.func = stmmac_test_flowctrl_validate;
 	tpriv->pt.dev = priv->dev;
 	tpriv->pt.af_packet_priv = tpriv;
-	dev_add_pack(&tpriv->pt);
+	stmmac_sft_add_pack(&tpriv->pt);
 
 	/* Compute minimum number of packets to make FIFO full */
 	pkt_count = rx_fifo_size;
@@ -823,7 +871,7 @@ static int stmmac_test_flowctrl(struct stmmac_priv *priv)
 cleanup:
 	dev_mc_del(priv->dev, paddr);
 	dev_set_promiscuity(priv->dev, -1);
-	dev_remove_pack(&tpriv->pt);
+	stmmac_sft_remove_pack(&tpriv->pt);
 	kfree(tpriv);
 	return ret;
 }
@@ -928,7 +976,7 @@ static int __stmmac_test_vlanfilt(struct stmmac_priv *priv)
 	 * HASH values.
 	 */
 	tpriv->vlan_id = 0x123;
-	dev_add_pack(&tpriv->pt);
+	stmmac_sft_add_pack(&tpriv->pt);
 
 	ret = vlan_vid_add(priv->dev, htons(ETH_P_8021Q), tpriv->vlan_id);
 	if (ret)
@@ -968,7 +1016,7 @@ static int __stmmac_test_vlanfilt(struct stmmac_priv *priv)
 vlan_del:
 	vlan_vid_del(priv->dev, htons(ETH_P_8021Q), tpriv->vlan_id);
 cleanup:
-	dev_remove_pack(&tpriv->pt);
+	stmmac_sft_remove_pack(&tpriv->pt);
 	kfree(tpriv);
 	return ret;
 }
@@ -1022,7 +1070,7 @@ static int __stmmac_test_dvlanfilt(struct stmmac_priv *priv)
 	 * HASH values.
 	 */
 	tpriv->vlan_id = 0x123;
-	dev_add_pack(&tpriv->pt);
+	stmmac_sft_add_pack(&tpriv->pt);
 
 	ret = vlan_vid_add(priv->dev, htons(ETH_P_8021AD), tpriv->vlan_id);
 	if (ret)
@@ -1062,7 +1110,7 @@ static int __stmmac_test_dvlanfilt(struct stmmac_priv *priv)
 vlan_del:
 	vlan_vid_del(priv->dev, htons(ETH_P_8021AD), tpriv->vlan_id);
 cleanup:
-	dev_remove_pack(&tpriv->pt);
+	stmmac_sft_remove_pack(&tpriv->pt);
 	kfree(tpriv);
 	return ret;
 }
@@ -1293,7 +1341,7 @@ static int stmmac_test_vlanoff_common(struct stmmac_priv *priv, bool svlan)
 	tpriv->pt.af_packet_priv = tpriv;
 	tpriv->packet = &attr;
 	tpriv->vlan_id = 0x123;
-	dev_add_pack(&tpriv->pt);
+	stmmac_sft_add_pack(&tpriv->pt);
 
 	ret = vlan_vid_add(priv->dev, htons(proto), tpriv->vlan_id);
 	if (ret)
@@ -1320,7 +1368,7 @@ static int stmmac_test_vlanoff_common(struct stmmac_priv *priv, bool svlan)
 vlan_del:
 	vlan_vid_del(priv->dev, htons(proto), tpriv->vlan_id);
 cleanup:
-	dev_remove_pack(&tpriv->pt);
+	stmmac_sft_remove_pack(&tpriv->pt);
 	kfree(tpriv);
 	return ret;
 }
-- 
2.55.0

Re: [PATCH net v2 1/6] net: stmmac: selftests: Support running selftests on DSA conduits

[Nicolai Buchwitz]

On 10.9.2026 17:13, Maxime Chevallier wrote:
> Most stmmac selftests rely on dev_add_pack() to add custom handlers,
> that validate the packets sent to ourselves through MAC loopback.
> 
> However, when the stmmac-driven interface is a DSA CPU conduit, all
> frames that are received have ETH_P_XDSA as a protocol, even though 
> they
> don't actually contain any tag as they come from the loopback and not
> the switch.
> 
> This will prevent any incoming packet to match our packet handlers.
> 
> Let's register a ETH_P_ALL packet handler when we detect that we're a
> DSA conduit, and use a proxy packet handler to filter the h_proto.
> 
> Note that we may still receive incoming packets from the switch, but
> these frames shouldn't interfere with the very specific frames used for
> selftests, and stmmac selftests in general aren't safe against external
> traffic interferences.
> 
> This was validated on a WPQ864 devkit for IPQ8064, that has the SoC
> connected to a QCA8k switch.
> 
> The ARP offload's packet handler is left alone, this feature is just 
> not
> implemented in stmmac and due for removal.
> 
> Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> ---

> [...]

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>

Thanks,
Nicolai

[PATCH net v2 2/6] net: stmmac: selftests: Validate EEE based on the actual LPI timer value

[Maxime Chevallier]

The EEE selftest is a 2-step test :
 - It validates that we enter in LPI mode with the
   irq_tx_path_in_lpi_mode_n counter
 - It then validates that we exit LPI when sending a frame, with the
   irq_tx_path_exit_lpi_mode_n counter.

The current state of the test lacks 2 main things :

 - We don't know exactly when was the previous frame sent (it's from the
   previous selftest)

 - The timeout is hardcoded, while the LPI is entered after a
   user-configurable delay. On top of that, the timeout loop uses a
   pre-decrement iterator (--retries) that actually only iterate nine
   times, so 900ms while the default LPI value is 1 second.

Let's therefore make it more deterministic :

 - Send a frame at the beginning of the test
 - Wait for more than the lpi timer value, we timeout after about twice
   the value,
 - Then send another frame, and verify that we do go out of LPI, also
   with a timeout.

Note that the test's goal isn't to validate the LPI timer value itself,
only that we enter/leave LPI mode.

Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 .../stmicro/stmmac/stmmac_selftests.c         | 39 +++++++++++++++----
 1 file changed, 32 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
index 6503678b646e..a8280834185c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
@@ -462,7 +462,7 @@ static int stmmac_test_mmc(struct stmmac_priv *priv)
 static int stmmac_test_eee(struct stmmac_priv *priv)
 {
 	struct stmmac_extra_stats *initial, *final;
-	int retries = 10;
+	unsigned long timeout, max_duration;
 	int ret;
 
 	if (!priv->dma_cap.eee || !priv->eee_active)
@@ -478,14 +478,21 @@ static int stmmac_test_eee(struct stmmac_priv *priv)
 		goto out_free_initial;
 	}
 
+	/* Snapshot stats, we want to count the in_lpi events. We may enter
+	 * LPI just after the packet was sent.
+	 */
 	memcpy(initial, &priv->xstats, sizeof(*initial));
 
+	/* Send a frame, then wait to enter LPI */
 	ret = stmmac_test_mac_loopback(priv);
 	if (ret)
 		goto out_free_final;
 
+	max_duration = usecs_to_jiffies(2 * priv->tx_lpi_timer);
+
 	/* We have no traffic in the line so, sooner or later it will go LPI */
-	while (--retries) {
+	timeout = jiffies + max_duration;
+	while (!time_after(jiffies, timeout)) {
 		memcpy(final, &priv->xstats, sizeof(*final));
 
 		if (final->irq_tx_path_in_lpi_mode_n >
@@ -494,20 +501,38 @@ static int stmmac_test_eee(struct stmmac_priv *priv)
 		msleep(100);
 	}
 
-	if (!retries) {
+	memcpy(final, &priv->xstats, sizeof(*final));
+	if (final->irq_tx_path_in_lpi_mode_n <=
+	    initial->irq_tx_path_in_lpi_mode_n) {
 		ret = -ETIMEDOUT;
 		goto out_free_final;
 	}
 
-	if (final->irq_tx_path_in_lpi_mode_n <=
-	    initial->irq_tx_path_in_lpi_mode_n) {
-		ret = -EINVAL;
+	/* Re-snapshot, as we want to measure exit_lpi events. We should be
+	 * in LPI right now.
+	 */
+	memcpy(initial, &priv->xstats, sizeof(*initial));
+
+	/* TX something so we go out of LPI */
+	ret = stmmac_test_mac_loopback(priv);
+	if (ret)
 		goto out_free_final;
+
+	/* Wait for the exit LPI interrupt */
+	timeout = jiffies + max_duration;
+	while (!time_after(jiffies, timeout)) {
+		memcpy(final, &priv->xstats, sizeof(*final));
+
+		if (final->irq_tx_path_exit_lpi_mode_n >
+		    initial->irq_tx_path_exit_lpi_mode_n)
+			break;
+		msleep(100);
 	}
 
+	memcpy(final, &priv->xstats, sizeof(*final));
 	if (final->irq_tx_path_exit_lpi_mode_n <=
 	    initial->irq_tx_path_exit_lpi_mode_n) {
-		ret = -EINVAL;
+		ret = -ETIMEDOUT;
 		goto out_free_final;
 	}
 
-- 
2.55.0

Re: [PATCH net v2 2/6] net: stmmac: selftests: Validate EEE based on the actual LPI timer value

[Nicolai Buchwitz]

Hi Maxime,

On 10.9.2026 17:13, Maxime Chevallier wrote:
> The EEE selftest is a 2-step test :
>  - It validates that we enter in LPI mode with the
>    irq_tx_path_in_lpi_mode_n counter
>  - It then validates that we exit LPI when sending a frame, with the
>    irq_tx_path_exit_lpi_mode_n counter.
> 
> The current state of the test lacks 2 main things :
> 
>  - We don't know exactly when was the previous frame sent (it's from 
> the
>    previous selftest)
> 
>  - The timeout is hardcoded, while the LPI is entered after a
>    user-configurable delay. On top of that, the timeout loop uses a
>    pre-decrement iterator (--retries) that actually only iterate nine
>    times, so 900ms while the default LPI value is 1 second.
> 
> Let's therefore make it more deterministic :
> 
>  - Send a frame at the beginning of the test
>  - Wait for more than the lpi timer value, we timeout after about twice
>    the value,
>  - Then send another frame, and verify that we do go out of LPI, also
>    with a timeout.
> 
> Note that the test's goal isn't to validate the LPI timer value itself,
> only that we enter/leave LPI mode.
> 
> Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> ---
>  .../stmicro/stmmac/stmmac_selftests.c         | 39 +++++++++++++++----
>  1 file changed, 32 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c 
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> index 6503678b646e..a8280834185c 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> @@ -462,7 +462,7 @@ static int stmmac_test_mmc(struct stmmac_priv 
> *priv)
>  static int stmmac_test_eee(struct stmmac_priv *priv)
>  {
>  	struct stmmac_extra_stats *initial, *final;
> -	int retries = 10;
> +	unsigned long timeout, max_duration;
>  	int ret;
> 
>  	if (!priv->dma_cap.eee || !priv->eee_active)
> @@ -478,14 +478,21 @@ static int stmmac_test_eee(struct stmmac_priv 
> *priv)
>  		goto out_free_initial;
>  	}
> 
> +	/* Snapshot stats, we want to count the in_lpi events. We may enter
> +	 * LPI just after the packet was sent.
> +	 */
>  	memcpy(initial, &priv->xstats, sizeof(*initial));
> 
> +	/* Send a frame, then wait to enter LPI */
>  	ret = stmmac_test_mac_loopback(priv);
>  	if (ret)
>  		goto out_free_final;
> 
> +	max_duration = usecs_to_jiffies(2 * priv->tx_lpi_timer);
> +
>  	/* We have no traffic in the line so, sooner or later it will go LPI 
> */
> -	while (--retries) {
> +	timeout = jiffies + max_duration;
> +	while (!time_after(jiffies, timeout)) {
>  		memcpy(final, &priv->xstats, sizeof(*final));
> 
>  		if (final->irq_tx_path_in_lpi_mode_n >
> @@ -494,20 +501,38 @@ static int stmmac_test_eee(struct stmmac_priv 
> *priv)
>  		msleep(100);
>  	}
> 
> -	if (!retries) {
> +	memcpy(final, &priv->xstats, sizeof(*final));
> +	if (final->irq_tx_path_in_lpi_mode_n <=
> +	    initial->irq_tx_path_in_lpi_mode_n) {
>  		ret = -ETIMEDOUT;
>  		goto out_free_final;
>  	}
> 
> -	if (final->irq_tx_path_in_lpi_mode_n <=
> -	    initial->irq_tx_path_in_lpi_mode_n) {
> -		ret = -EINVAL;
> +	/* Re-snapshot, as we want to measure exit_lpi events. We should be
> +	 * in LPI right now.
> +	 */
> +	memcpy(initial, &priv->xstats, sizeof(*initial));
> +
> +	/* TX something so we go out of LPI */
> +	ret = stmmac_test_mac_loopback(priv);
> +	if (ret)
>  		goto out_free_final;
> +
> +	/* Wait for the exit LPI interrupt */
> +	timeout = jiffies + max_duration;
> +	while (!time_after(jiffies, timeout)) {
> +		memcpy(final, &priv->xstats, sizeof(*final));
> +
> +		if (final->irq_tx_path_exit_lpi_mode_n >
> +		    initial->irq_tx_path_exit_lpi_mode_n)
> +			break;
> +		msleep(100);
>  	}
> 
> +	memcpy(final, &priv->xstats, sizeof(*final));
>  	if (final->irq_tx_path_exit_lpi_mode_n <=
>  	    initial->irq_tx_path_exit_lpi_mode_n) {
> -		ret = -EINVAL;
> +		ret = -ETIMEDOUT;
>  		goto out_free_final;
>  	}

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de

Thanks,
Nicolai

Re: [PATCH net v2 2/6] net: stmmac: selftests: Validate EEE based on the actual LPI timer value

[Nicolai Buchwitz]

Hi Maxime,

Sorry for the noise, but after having a second look, there is something
which I think should be discussed at least.

On 10.9.2026 17:13, Maxime Chevallier wrote:
> The EEE selftest is a 2-step test :
>  - It validates that we enter in LPI mode with the
>    irq_tx_path_in_lpi_mode_n counter
>  - It then validates that we exit LPI when sending a frame, with the
>    irq_tx_path_exit_lpi_mode_n counter.
> 
> The current state of the test lacks 2 main things :
> 
>  - We don't know exactly when was the previous frame sent (it's from 
> the
>    previous selftest)
> 
>  - The timeout is hardcoded, while the LPI is entered after a
>    user-configurable delay. On top of that, the timeout loop uses a
>    pre-decrement iterator (--retries) that actually only iterate nine
>    times, so 900ms while the default LPI value is 1 second.
> 
> Let's therefore make it more deterministic :
> 
>  - Send a frame at the beginning of the test
>  - Wait for more than the lpi timer value, we timeout after about twice
>    the value,
>  - Then send another frame, and verify that we do go out of LPI, also
>    with a timeout.
> 
> Note that the test's goal isn't to validate the LPI timer value itself,
> only that we enter/leave LPI mode.
> 
> Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> ---
> [...]

> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c 
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> [...]

> 
> +	max_duration = usecs_to_jiffies(2 * priv->tx_lpi_timer);

tx_lpi_timer comes direct from ethtool as an unvalidated u32. So if a 
(arguable privileged
user) does 'ethtool --set-eee eth0 tx-lpi-timer 1000000000', the code 
will sleep ~2000 seconds
under rtnl_lock. Tge old code capped it at 900 ms regardless of the 
timer.

Thus I think we should clamp it at some sane value. Feel free to keep my 
R-b with the clamp.

> [...]

Regards,
Nicolai

Re: [PATCH net v2 2/6] net: stmmac: selftests: Validate EEE based on the actual LPI timer value

[Maxime Chevallier]

Hi Nicolai,

On 9/10/26 20:50, Nicolai Buchwitz wrote:

>> +    max_duration = usecs_to_jiffies(2 * priv->tx_lpi_timer);
> 
> tx_lpi_timer comes direct from ethtool as an unvalidated u32. So if a (arguable privileged
> user) does 'ethtool --set-eee eth0 tx-lpi-timer 1000000000', the code will sleep ~2000 seconds
> under rtnl_lock. Tge old code capped it at 900 ms regardless of the timer.
> 
> Thus I think we should clamp it at some sane value. Feel free to keep my R-b with the clamp.

I was wondering if 802.3 said anything about the LPI timer value, but
Clause 78 says :

  78.1.2.1.3 When generated

  Specification of the time when this primitive is generated by the LPI
  client is out of the scope of this standard.

I'll clamp that as a safety precaution.

As a side-note, there are other limitations, that apply to both eee
and flow control. Even though we're in MAC loopback mode, the link
MUST be up for the selftests to run, and both EEE and Pause are
affected by the autoneg results, and this will affect the selftest
outcome.

I'll address that in another series though, but I'll send a V3 for the
clamping still :)

Thanks for taking a look,

Maxime

[PATCH net v2 3/6] net: stmmac: selftests: Check the dev->features for S-TAG offload testing

[Maxime Chevallier]

The S-TAG offload insertion incorrectly checks the dvlan (double vlan)
DMA cap, which is different than S-TAG support. Use
NETIF_F_HW_VLAN_STAG_TX to check if the feature is supported instead.

Note that this flag isn't set in stmmac yet, but contrary to ARP
offload, this is a feature that has a chance to get there eventually so
let's leave the selftest here for now. It'll report -EOPNOTSUPP in the
meantime.

Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
index a8280834185c..f3a533bc6bb6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
@@ -1405,7 +1405,7 @@ static int stmmac_test_vlanoff(struct stmmac_priv *priv)
 
 static int stmmac_test_svlanoff(struct stmmac_priv *priv)
 {
-	if (!priv->dma_cap.dvlan)
+	if (!(priv->dev->features & NETIF_F_HW_VLAN_STAG_TX))
 		return -EOPNOTSUPP;
 	return stmmac_test_vlanoff_common(priv, true);
 }
-- 
2.55.0

Re: [PATCH net v2 3/6] net: stmmac: selftests: Check the dev->features for S-TAG offload testing

[Nicolai Buchwitz]

On 10.9.2026 17:14, Maxime Chevallier wrote:
> The S-TAG offload insertion incorrectly checks the dvlan (double vlan)
> DMA cap, which is different than S-TAG support. Use
> NETIF_F_HW_VLAN_STAG_TX to check if the feature is supported instead.
> 
> Note that this flag isn't set in stmmac yet, but contrary to ARP
> offload, this is a feature that has a chance to get there eventually so
> let's leave the selftest here for now. It'll report -EOPNOTSUPP in the
> meantime.
> 
> Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c 
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> index a8280834185c..f3a533bc6bb6 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> @@ -1405,7 +1405,7 @@ static int stmmac_test_vlanoff(struct stmmac_priv 
> *priv)
> 
>  static int stmmac_test_svlanoff(struct stmmac_priv *priv)
>  {
> -	if (!priv->dma_cap.dvlan)
> +	if (!(priv->dev->features & NETIF_F_HW_VLAN_STAG_TX))
>  		return -EOPNOTSUPP;
>  	return stmmac_test_vlanoff_common(priv, true);
>  }

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>

Thanks,
Nicolai

[PATCH net v2 4/6] net: stmmac: selftests: Capture all packets for vlan checks

[Maxime Chevallier]

While we use vlan_vid_add to trigger the tag filtering machinery
in the driver, there's no netdev associated to the VLAN. This causes the
skb to arrive with empty skb->vlan_tci fields, as the packet is marked
OTHERHOST in __netif_receive_skb_core(), and we fail our validation.

Let's use the proxy mechanism introduced for DSA, that registers a
ETH_P_ALL packet handler that runs earlier, before the vlan netdev
lookup, then filters for the correct ethertype before passing an skb
clone to our validation function.

Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
index f3a533bc6bb6..ec56ee0031ab 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
@@ -241,6 +241,7 @@ struct stmmac_test_priv {
 	__be16 packet_type;
 	int (*func)(struct sk_buff *skb, struct net_device *ndev,
 		    struct packet_type *pt, struct net_device *orig_ndev);
+	bool capture_all;
 	int double_vlan;
 	int vlan_id;
 	int ok;
@@ -343,7 +344,7 @@ static void stmmac_sft_add_pack(struct packet_type *pt)
 {
 	struct stmmac_test_priv *tpriv = pt->af_packet_priv;
 
-	if (netdev_uses_dsa(tpriv->pt.dev)) {
+	if (netdev_uses_dsa(tpriv->pt.dev) || tpriv->capture_all) {
 		tpriv->packet_type = tpriv->pt.type;
 		tpriv->func = tpriv->pt.func;
 
@@ -994,6 +995,7 @@ static int __stmmac_test_vlanfilt(struct stmmac_priv *priv)
 	tpriv->pt.dev = priv->dev;
 	tpriv->pt.af_packet_priv = tpriv;
 	tpriv->packet = &attr;
+	tpriv->capture_all = true;
 
 	/*
 	 * As we use HASH filtering, false positives may appear. This is a
@@ -1088,6 +1090,7 @@ static int __stmmac_test_dvlanfilt(struct stmmac_priv *priv)
 	tpriv->pt.dev = priv->dev;
 	tpriv->pt.af_packet_priv = tpriv;
 	tpriv->packet = &attr;
+	tpriv->capture_all = true;
 
 	/*
 	 * As we use HASH filtering, false positives may appear. This is a
@@ -1366,6 +1369,7 @@ static int stmmac_test_vlanoff_common(struct stmmac_priv *priv, bool svlan)
 	tpriv->pt.af_packet_priv = tpriv;
 	tpriv->packet = &attr;
 	tpriv->vlan_id = 0x123;
+	tpriv->capture_all = true;
 	stmmac_sft_add_pack(&tpriv->pt);
 
 	ret = vlan_vid_add(priv->dev, htons(proto), tpriv->vlan_id);
-- 
2.55.0

Re: [PATCH net v2 4/6] net: stmmac: selftests: Capture all packets for vlan checks

[Nicolai Buchwitz]

On 10.9.2026 17:14, Maxime Chevallier wrote:
> While we use vlan_vid_add to trigger the tag filtering machinery
> in the driver, there's no netdev associated to the VLAN. This causes 
> the
> skb to arrive with empty skb->vlan_tci fields, as the packet is marked
> OTHERHOST in __netif_receive_skb_core(), and we fail our validation.
> 
> Let's use the proxy mechanism introduced for DSA, that registers a
> ETH_P_ALL packet handler that runs earlier, before the vlan netdev
> lookup, then filters for the correct ethertype before passing an skb
> clone to our validation function.
> 
> Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support")
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c 
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> index f3a533bc6bb6..ec56ee0031ab 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> @@ -241,6 +241,7 @@ struct stmmac_test_priv {
>  	__be16 packet_type;
>  	int (*func)(struct sk_buff *skb, struct net_device *ndev,
>  		    struct packet_type *pt, struct net_device *orig_ndev);
> +	bool capture_all;
>  	int double_vlan;
>  	int vlan_id;
>  	int ok;
> @@ -343,7 +344,7 @@ static void stmmac_sft_add_pack(struct packet_type 
> *pt)
>  {
>  	struct stmmac_test_priv *tpriv = pt->af_packet_priv;
> 
> -	if (netdev_uses_dsa(tpriv->pt.dev)) {
> +	if (netdev_uses_dsa(tpriv->pt.dev) || tpriv->capture_all) {
>  		tpriv->packet_type = tpriv->pt.type;
>  		tpriv->func = tpriv->pt.func;
> 
> @@ -994,6 +995,7 @@ static int __stmmac_test_vlanfilt(struct 
> stmmac_priv *priv)
>  	tpriv->pt.dev = priv->dev;
>  	tpriv->pt.af_packet_priv = tpriv;
>  	tpriv->packet = &attr;
> +	tpriv->capture_all = true;
> 
>  	/*
>  	 * As we use HASH filtering, false positives may appear. This is a
> @@ -1088,6 +1090,7 @@ static int __stmmac_test_dvlanfilt(struct 
> stmmac_priv *priv)
>  	tpriv->pt.dev = priv->dev;
>  	tpriv->pt.af_packet_priv = tpriv;
>  	tpriv->packet = &attr;
> +	tpriv->capture_all = true;
> 
>  	/*
>  	 * As we use HASH filtering, false positives may appear. This is a
> @@ -1366,6 +1369,7 @@ static int stmmac_test_vlanoff_common(struct 
> stmmac_priv *priv, bool svlan)
>  	tpriv->pt.af_packet_priv = tpriv;
>  	tpriv->packet = &attr;
>  	tpriv->vlan_id = 0x123;
> +	tpriv->capture_all = true;
>  	stmmac_sft_add_pack(&tpriv->pt);
> 
>  	ret = vlan_vid_add(priv->dev, htons(proto), tpriv->vlan_id);

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>

Thanks,
Nicolai

[PATCH net v2 5/6] net: stmmac: size the RX buffers from the frame length, not the MTU

[Maxime Chevallier]

When picking the buffsize to use based on the MTU, we shouldn't check
only the MTU value, but also :
 - ETH_HLEN for the L2 header,
 - up to 2 VLAN tags,
 - the FCS,
 - the NET_IP_ALIGN

The default bufsize is 1536 bytes, which is enough to contain all the
above so this hasn't surfaced before, but the addition of NET_IP_ALIGN
to the start of buffer address tripped the Jumbo selftest, leading to
this discovery.

With that, we don't need the '>=' checks on the buffer len, we can use
more consistent comparison operators in stmmac_set_bfsize.

Fixes: 286a83721720 ("stmmac: add CHAINED descriptor mode support (V4)")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 .../net/ethernet/stmicro/stmmac/stmmac_main.c | 20 ++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 5fe7e95fdd34..3664a298574a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1536,17 +1536,17 @@ static unsigned int stmmac_rx_offset(struct stmmac_priv *priv)
 	return NET_SKB_PAD + NET_IP_ALIGN;
 }
 
-static int stmmac_set_bfsize(int mtu)
+static int stmmac_set_bfsize(int len)
 {
 	int ret;
 
-	if (mtu >= BUF_SIZE_8KiB)
+	if (len > BUF_SIZE_8KiB)
 		ret = BUF_SIZE_16KiB;
-	else if (mtu >= BUF_SIZE_4KiB)
+	else if (len > BUF_SIZE_4KiB)
 		ret = BUF_SIZE_8KiB;
-	else if (mtu >= BUF_SIZE_2KiB)
+	else if (len > BUF_SIZE_2KiB)
 		ret = BUF_SIZE_4KiB;
-	else if (mtu > DEFAULT_BUFSIZE)
+	else if (len > DEFAULT_BUFSIZE)
 		ret = BUF_SIZE_2KiB;
 	else
 		ret = DEFAULT_BUFSIZE;
@@ -4063,7 +4063,7 @@ static struct stmmac_dma_conf *
 stmmac_setup_dma_desc(struct stmmac_priv *priv, unsigned int mtu)
 {
 	struct stmmac_dma_conf *dma_conf;
-	int bfsize, ret;
+	int bfsize, len, ret;
 	u8 chan;
 
 	dma_conf = kzalloc_obj(*dma_conf);
@@ -4073,13 +4073,15 @@ stmmac_setup_dma_desc(struct stmmac_priv *priv, unsigned int mtu)
 		return ERR_PTR(-ENOMEM);
 	}
 
-	/* Returns 0 or BUF_SIZE_16KiB if mtu > 8KiB and dwmac4 or ring mode */
-	bfsize = stmmac_set_16kib_bfsize(priv, mtu);
+	len = mtu + ETH_HLEN + 2 * VLAN_HLEN + ETH_FCS_LEN + NET_IP_ALIGN;
+
+	/* Returns 0 or BUF_SIZE_16KiB if len > 8KiB and dwmac4 or ring mode */
+	bfsize = stmmac_set_16kib_bfsize(priv, len);
 	if (bfsize < 0)
 		bfsize = 0;
 
 	if (bfsize < BUF_SIZE_16KiB)
-		bfsize = stmmac_set_bfsize(mtu);
+		bfsize = stmmac_set_bfsize(len);
 
 	dma_conf->dma_buf_sz = bfsize;
 	/* Chose the tx/rx size from the already defined one in the
-- 
2.55.0

Re: [PATCH net v2 5/6] net: stmmac: size the RX buffers from the frame length, not the MTU

[Nicolai Buchwitz]

On 10.9.2026 17:14, Maxime Chevallier wrote:
> When picking the buffsize to use based on the MTU, we shouldn't check
> only the MTU value, but also :
>  - ETH_HLEN for the L2 header,
>  - up to 2 VLAN tags,
>  - the FCS,
>  - the NET_IP_ALIGN
> 
> The default bufsize is 1536 bytes, which is enough to contain all the
> above so this hasn't surfaced before, but the addition of NET_IP_ALIGN
> to the start of buffer address tripped the Jumbo selftest, leading to
> this discovery.
> 
> With that, we don't need the '>=' checks on the buffer len, we can use
> more consistent comparison operators in stmmac_set_bfsize.
> 
> Fixes: 286a83721720 ("stmmac: add CHAINED descriptor mode support 
> (V4)")
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> ---
>  .../net/ethernet/stmicro/stmmac/stmmac_main.c | 20 ++++++++++---------
>  1 file changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c 
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 5fe7e95fdd34..3664a298574a 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -1536,17 +1536,17 @@ static unsigned int stmmac_rx_offset(struct 
> stmmac_priv *priv)
>  	return NET_SKB_PAD + NET_IP_ALIGN;
>  }
> 
> -static int stmmac_set_bfsize(int mtu)
> +static int stmmac_set_bfsize(int len)
>  {
>  	int ret;
> 
> -	if (mtu >= BUF_SIZE_8KiB)
> +	if (len > BUF_SIZE_8KiB)
>  		ret = BUF_SIZE_16KiB;



> -	else if (mtu >= BUF_SIZE_4KiB)
> +	else if (len > BUF_SIZE_4KiB)
>  		ret = BUF_SIZE_8KiB;
> -	else if (mtu >= BUF_SIZE_2KiB)
> +	else if (len > BUF_SIZE_2KiB)
>  		ret = BUF_SIZE_4KiB;
> -	else if (mtu > DEFAULT_BUFSIZE)
> +	else if (len > DEFAULT_BUFSIZE)
>  		ret = BUF_SIZE_2KiB;
>  	else
>  		ret = DEFAULT_BUFSIZE;
> @@ -4063,7 +4063,7 @@ static struct stmmac_dma_conf *
>  stmmac_setup_dma_desc(struct stmmac_priv *priv, unsigned int mtu)
>  {
>  	struct stmmac_dma_conf *dma_conf;
> -	int bfsize, ret;
> +	int bfsize, len, ret;
>  	u8 chan;
> 
>  	dma_conf = kzalloc_obj(*dma_conf);
> @@ -4073,13 +4073,15 @@ stmmac_setup_dma_desc(struct stmmac_priv *priv, 
> unsigned int mtu)
>  		return ERR_PTR(-ENOMEM);
>  	}
> 
> -	/* Returns 0 or BUF_SIZE_16KiB if mtu > 8KiB and dwmac4 or ring mode 
> */
> -	bfsize = stmmac_set_16kib_bfsize(priv, mtu);
> +	len = mtu + ETH_HLEN + 2 * VLAN_HLEN + ETH_FCS_LEN + NET_IP_ALIGN;
> +
> +	/* Returns 0 or BUF_SIZE_16KiB if len > 8KiB and dwmac4 or ring mode 
> */
> +	bfsize = stmmac_set_16kib_bfsize(priv, len);
>  	if (bfsize < 0)
>  		bfsize = 0;
> 
>  	if (bfsize < BUF_SIZE_16KiB)
> -		bfsize = stmmac_set_bfsize(mtu);
> +		bfsize = stmmac_set_bfsize(len);
> 
>  	dma_conf->dma_buf_sz = bfsize;
>  	/* Chose the tx/rx size from the already defined one in the

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>

Thanks,
Nicolai

[PATCH net v2 6/6] net: stmmac: selftests: Account for alignment shift on dwmac1000 for Jumbo test

[Maxime Chevallier]

On dwmac1000, we currently only support single-descriptor frames. The
Jumbo test started failing when NET_IP_ALIGN was added to align the IP
header, as this tests tries to send the biggest possible frame.

On dwmac1000 the DMA transfer is aligned on 4-bytes, so adding a 2-byte
shift at the start-of-buffer address means it takes a whole extra 4-byte
DMA burst to receive the Jumbo packet, causing it to spill over the next
descriptor.

This doesn't seem to happen on dwmac4 and xgmac that appear to correctly
handle unaligned xfers (only tested on dwmac4)

Let's account for that in the Jumbo test, reduce the size of our big
packet by the align size.

Fixes: 23680bf5f8c6 ("net: stmmac: restore NET_IP_ALIGN in the RX DMA offset")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
index ec56ee0031ab..fc8d69260f43 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
@@ -1776,6 +1776,9 @@ static int __stmmac_test_jumbo(struct stmmac_priv *priv, u16 queue)
 	struct stmmac_packet_attrs attr = { };
 	int size = priv->dma_conf.dma_buf_sz;
 
+	if (!dwmac_is_xmac(priv->plat->core_type))
+		size -= NET_IP_ALIGN;
+
 	attr.dst = priv->dev->dev_addr;
 	attr.max_size = size - ETH_FCS_LEN;
 	attr.queue_mapping = queue;
-- 
2.55.0

Re: [PATCH net v2 6/6] net: stmmac: selftests: Account for alignment shift on dwmac1000 for Jumbo test

[Nicolai Buchwitz]

On 10.9.2026 17:14, Maxime Chevallier wrote:
> On dwmac1000, we currently only support single-descriptor frames. The
> Jumbo test started failing when NET_IP_ALIGN was added to align the IP
> header, as this tests tries to send the biggest possible frame.
> 
> On dwmac1000 the DMA transfer is aligned on 4-bytes, so adding a 2-byte
> shift at the start-of-buffer address means it takes a whole extra 
> 4-byte
> DMA burst to receive the Jumbo packet, causing it to spill over the 
> next
> descriptor.
> 
> This doesn't seem to happen on dwmac4 and xgmac that appear to 
> correctly
> handle unaligned xfers (only tested on dwmac4)
> 
> Let's account for that in the Jumbo test, reduce the size of our big
> packet by the align size.
> 
> Fixes: 23680bf5f8c6 ("net: stmmac: restore NET_IP_ALIGN in the RX DMA 
> offset")
> Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> ---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c 
> b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> index ec56ee0031ab..fc8d69260f43 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c
> @@ -1776,6 +1776,9 @@ static int __stmmac_test_jumbo(struct stmmac_priv 
> *priv, u16 queue)
>  	struct stmmac_packet_attrs attr = { };
>  	int size = priv->dma_conf.dma_buf_sz;
> 
> +	if (!dwmac_is_xmac(priv->plat->core_type))
> +		size -= NET_IP_ALIGN;
> +
>  	attr.dst = priv->dev->dev_addr;
>  	attr.max_size = size - ETH_FCS_LEN;
>  	attr.queue_mapping = queue;

Reviewed-by: Nicolai Buchwitz <nb@tipi-net.de>

Thanks,
Nicolai