* [PATCH net v7 1/4] net: ethernet: oa_tc6: Protect skb pointer used by two different kernel instances
2026-08-24 21:57 [PATCH net v7 0/4] Fix to possible skb leak due to race condtion in tx path Selvamani Rajagopal via B4 Relay
@ 2026-08-24 21:57 ` Selvamani Rajagopal via B4 Relay
2026-08-24 21:57 ` [PATCH net v7 2/4] net: ethernet: oa_tc6: Improve the error recovery Selvamani Rajagopal via B4 Relay
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Selvamani Rajagopal via B4 Relay @ 2026-08-24 21:57 UTC (permalink / raw)
To: Parthiban Veerasooran, Andrew Lunn, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Selvamani Rajagopal
Cc: netdev, linux-kernel, Parthiban Veerasooran, Andrew Lunn
From: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
Threaded IRQ uses waiting_tx_skb. Transmit path also uses this pointer
without any mutual exclusion protection. As a result, it might leak skb
buffer, particularly if threaded IRQ sets disable_traffic true after
start_xmit already checked and found that disable_traffic being false,
if they happen to run on different cores.
On fatal error, where disable_traffic is set, transmit function drops the
packet and return NETDEV_TX_OK. Due to this change, skb_linearize call
is moved up to the beginning of the transmit function.
Since skb buffer may be freed from different contexts, dev_kfree_skb_any
is used to free skb buffer now, replacing one of the kfree_skb call.
oa_tc6_exit disables the irq before setting disable_traffic true.
Fixes: b542d13fab0f ("net: ethernet: oa_tc6: Interrupt is active low, level triggered.")
Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
---
changes in v7
- No change
changes in v6
- Updated the comment section for start_xmit function.
- disable_irq is called first before setting disable_traffic flag
changes in v5
- Fixed the typo in commit message
changes in v4
- No change
changes in v3
- Added the missed out spin lock protection for waiting_tx_skb and
disable_traffic flag
changes in v2
- added the missing prefix to the title
---
drivers/net/ethernet/oa_tc6.c | 109 +++++++++++++++++++++++++++++-------------
1 file changed, 76 insertions(+), 33 deletions(-)
diff --git a/drivers/net/ethernet/oa_tc6.c b/drivers/net/ethernet/oa_tc6.c
index 417c15d1ff42..2f45001be0f5 100644
--- a/drivers/net/ethernet/oa_tc6.c
+++ b/drivers/net/ethernet/oa_tc6.c
@@ -693,6 +693,26 @@ static int oa_tc6_enable_data_transfer(struct oa_tc6 *tc6)
return oa_tc6_write_register(tc6, OA_TC6_REG_CONFIG0, value);
}
+/* Called when a frame that is meant to be transmitted, is dropped. */
+static void oa_tc6_drop_tx_skb(struct oa_tc6 *tc6, struct sk_buff *skb)
+{
+ if (skb) {
+ tc6->netdev->stats.tx_dropped++;
+ dev_kfree_skb_any(skb);
+ }
+}
+
+static struct sk_buff *oa_tc6_detach_waiting_tx_skb(struct oa_tc6 *tc6)
+{
+ struct sk_buff *skb;
+
+ lockdep_assert_held(&tc6->tx_skb_lock);
+ skb = tc6->waiting_tx_skb;
+ tc6->waiting_tx_skb = NULL;
+
+ return skb;
+}
+
static void oa_tc6_cleanup_ongoing_rx_skb(struct oa_tc6 *tc6)
{
if (tc6->rx_skb) {
@@ -704,26 +724,30 @@ static void oa_tc6_cleanup_ongoing_rx_skb(struct oa_tc6 *tc6)
static void oa_tc6_cleanup_ongoing_tx_skb(struct oa_tc6 *tc6)
{
- if (tc6->ongoing_tx_skb) {
- tc6->netdev->stats.tx_dropped++;
- kfree_skb(tc6->ongoing_tx_skb);
- tc6->ongoing_tx_skb = NULL;
- }
+ oa_tc6_drop_tx_skb(tc6, tc6->ongoing_tx_skb);
+ tc6->ongoing_tx_skb = NULL;
}
static void oa_tc6_cleanup_waiting_tx_skb(struct oa_tc6 *tc6)
{
- if (tc6->waiting_tx_skb) {
- tc6->netdev->stats.tx_dropped++;
- kfree_skb(tc6->waiting_tx_skb);
- tc6->waiting_tx_skb = NULL;
- }
+ struct sk_buff *skb;
+
+ spin_lock_bh(&tc6->tx_skb_lock);
+ skb = oa_tc6_detach_waiting_tx_skb(tc6);
+ spin_unlock_bh(&tc6->tx_skb_lock);
+
+ oa_tc6_drop_tx_skb(tc6, skb);
}
-static void oa_tc6_free_pending_skbs(struct oa_tc6 *tc6)
+static void oa_tc6_free_ongoing_skbs(struct oa_tc6 *tc6)
{
oa_tc6_cleanup_ongoing_tx_skb(tc6);
oa_tc6_cleanup_ongoing_rx_skb(tc6);
+}
+
+static void oa_tc6_free_pending_skbs(struct oa_tc6 *tc6)
+{
+ oa_tc6_free_ongoing_skbs(tc6);
oa_tc6_cleanup_waiting_tx_skb(tc6);
}
@@ -734,9 +758,15 @@ static void oa_tc6_free_pending_skbs(struct oa_tc6 *tc6)
static void oa_tc6_disable_traffic(struct oa_tc6 *tc6)
{
u32 regval = OA_TC6_INT_MASK0_ALL_INTERRUPTS;
+ struct sk_buff *skb;
+ spin_lock_bh(&tc6->tx_skb_lock);
tc6->disable_traffic = true;
- oa_tc6_free_pending_skbs(tc6);
+ skb = oa_tc6_detach_waiting_tx_skb(tc6);
+ spin_unlock_bh(&tc6->tx_skb_lock);
+
+ oa_tc6_drop_tx_skb(tc6, skb);
+ oa_tc6_free_ongoing_skbs(tc6);
oa_tc6_write_register(tc6, OA_TC6_REG_INT_MASK0, regval);
oa_tc6_read_register(tc6, OA_TC6_REG_STATUS0, ®val);
oa_tc6_write_register(tc6, OA_TC6_REG_STATUS0, regval);
@@ -1177,8 +1207,7 @@ static int oa_tc6_try_spi_transfer(struct oa_tc6 *tc6)
if (ret == -EAGAIN)
continue;
- oa_tc6_cleanup_ongoing_tx_skb(tc6);
- oa_tc6_cleanup_ongoing_rx_skb(tc6);
+ oa_tc6_free_ongoing_skbs(tc6);
netdev_err(tc6->netdev, "Device error: %d\n", ret);
return ret;
}
@@ -1200,15 +1229,20 @@ static irqreturn_t oa_tc6_macphy_threaded_irq(int irq, void *data)
* no need to attempt spi transfer, once it fails. Pending skbs
* are already freed.
*/
- if (!tc6->disable_traffic) {
- while (tc6->int_flag ||
- (tc6->waiting_tx_skb && tc6->tx_credits)) {
- ret = oa_tc6_try_spi_transfer(tc6);
- if (ret) {
- disable_irq_nosync(tc6->spi->irq);
- oa_tc6_disable_traffic(tc6);
- break;
- }
+ spin_lock_bh(&tc6->tx_skb_lock);
+ if (tc6->disable_traffic) {
+ spin_unlock_bh(&tc6->tx_skb_lock);
+ return IRQ_HANDLED;
+ }
+ spin_unlock_bh(&tc6->tx_skb_lock);
+
+ while (tc6->int_flag ||
+ (tc6->waiting_tx_skb && tc6->tx_credits)) {
+ ret = oa_tc6_try_spi_transfer(tc6);
+ if (ret) {
+ disable_irq_nosync(tc6->spi->irq);
+ oa_tc6_disable_traffic(tc6);
+ break;
}
}
@@ -1287,23 +1321,30 @@ EXPORT_SYMBOL_GPL(oa_tc6_zero_align_receive_frame_enable);
* @tc6: oa_tc6 struct.
* @skb: socket buffer in which the ethernet frame is stored.
*
- * Return: NETDEV_TX_OK if the transmit ethernet frame skb added in the tx_skb_q
- * otherwise returns NETDEV_TX_BUSY.
+ * Return: NETDEV_TX_OK either on successful queueing of the packet for
+ * transmission, or on packet getting dropped. Packet can be dropped due to
+ * failure in linearizing the buffer or disable_traffic is set due to
+ * earlier fatal error. Returns NETDEV_TX_BUSY when there is no room
+ * to queue the packet.
*/
netdev_tx_t oa_tc6_start_xmit(struct oa_tc6 *tc6, struct sk_buff *skb)
{
- if (tc6->disable_traffic || tc6->waiting_tx_skb) {
- netif_stop_queue(tc6->netdev);
- return NETDEV_TX_BUSY;
- }
-
if (skb_linearize(skb)) {
- dev_kfree_skb_any(skb);
- tc6->netdev->stats.tx_dropped++;
+ oa_tc6_drop_tx_skb(tc6, skb);
return NETDEV_TX_OK;
}
spin_lock_bh(&tc6->tx_skb_lock);
+ if (tc6->waiting_tx_skb) {
+ netif_stop_queue(tc6->netdev);
+ spin_unlock_bh(&tc6->tx_skb_lock);
+ return NETDEV_TX_BUSY;
+ }
+ if (tc6->disable_traffic) {
+ spin_unlock_bh(&tc6->tx_skb_lock);
+ oa_tc6_drop_tx_skb(tc6, skb);
+ return NETDEV_TX_OK;
+ }
tc6->waiting_tx_skb = skb;
spin_unlock_bh(&tc6->tx_skb_lock);
@@ -1462,8 +1503,10 @@ EXPORT_SYMBOL_GPL(oa_tc6_init);
*/
void oa_tc6_exit(struct oa_tc6 *tc6)
{
- tc6->disable_traffic = true;
disable_irq(tc6->spi->irq);
+ spin_lock_bh(&tc6->tx_skb_lock);
+ tc6->disable_traffic = true;
+ spin_unlock_bh(&tc6->tx_skb_lock);
oa_tc6_phy_exit(tc6);
oa_tc6_free_pending_skbs(tc6);
}
--
2.43.0
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH net v7 2/4] net: ethernet: oa_tc6: Improve the error recovery
2026-08-24 21:57 [PATCH net v7 0/4] Fix to possible skb leak due to race condtion in tx path Selvamani Rajagopal via B4 Relay
2026-08-24 21:57 ` [PATCH net v7 1/4] net: ethernet: oa_tc6: Protect skb pointer used by two different kernel instances Selvamani Rajagopal via B4 Relay
@ 2026-08-24 21:57 ` Selvamani Rajagopal via B4 Relay
2026-08-24 21:58 ` [PATCH net v7 3/4] net: ethernet: oa_tc6: Disable tx queues on fatal error Selvamani Rajagopal via B4 Relay
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Selvamani Rajagopal via B4 Relay @ 2026-08-24 21:57 UTC (permalink / raw)
To: Parthiban Veerasooran, Andrew Lunn, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Selvamani Rajagopal
Cc: netdev, linux-kernel, Parthiban Veerasooran, Andrew Lunn
From: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
When oversubscribed traffic causes lot of buffer overflow errors,
probably due to loss of data chunks, driver fails to find a
data chunk with end_valid bit set, before it runs out of sk buffer
space. As a result, assert is seen during skb_put.
Now, check is made if skb buffer has enough tailroom for the
incoming data before accepting. If there is no room, current
frame is abandoned and it will start looking for a data chunk
with start_valid bit, that is a new frame.
SK buffer allocation error is considered as recoverable error.
rx_buf_overflow flag is too specific and no longer the only
condition this flag is used for. Therefore it is renamed as
wait_until_start_valid. This is more appropriate as this flag
is used to look for the next data chunk with SV bit set, after
failures like buffer overflow, buffer allocation failure, skb pointer
validity besides buffer overflow error.
Not writing to status0 if it reads 0.
Fixes: d70a0d8f2f2d ("net: ethernet: oa_tc6: implement receive path to receive rx ethernet frames")
Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>
---
changes in v7
- No change
changes in v6
- Changed the rx_buf_overflow flag to more appropriate name
- Using skb_tailroom instead of skb fields directly
- Avoid reading status0, where it is not needed
changes in v5
- Changed the summary to match the convention
- Added more clarity to why the return code is not checked for
the call to oa_tc6_prcs_rx_frame_end
changes in v4
- rx_buf_overflow flag cleared, when end of frame and start of
frame are handled in the same data chunk.
- Added more comments to answer some of the AI review questions.
changes in v3
- Continue processing more chunks on error code -EAGAIN. Previously
we were bailing out.
changes in v2
- Check rx_skb pointer before new allocation and NULL before use.
---
drivers/net/ethernet/oa_tc6.c | 143 +++++++++++++++++++++++++++++++-----------
1 file changed, 108 insertions(+), 35 deletions(-)
diff --git a/drivers/net/ethernet/oa_tc6.c b/drivers/net/ethernet/oa_tc6.c
index 2f45001be0f5..657b1c6119da 100644
--- a/drivers/net/ethernet/oa_tc6.c
+++ b/drivers/net/ethernet/oa_tc6.c
@@ -83,7 +83,7 @@ struct oa_tc6 {
u16 spi_data_tx_buf_offset;
u16 tx_credits;
u8 rx_chunks_available;
- bool rx_buf_overflow;
+ bool wait_until_start_valid;
bool int_flag;
bool disable_traffic;
bool prot_ctrl;
@@ -751,6 +751,12 @@ static void oa_tc6_free_pending_skbs(struct oa_tc6 *tc6)
oa_tc6_cleanup_waiting_tx_skb(tc6);
}
+static void oa_tc6_look_for_new_frame(struct oa_tc6 *tc6)
+{
+ tc6->wait_until_start_valid = true;
+ oa_tc6_cleanup_ongoing_rx_skb(tc6);
+}
+
/* If the failure is at SPI interface level, masking and clearing
* the interrupt of the device won't work. Since SPI interrupt is
* disabled, it should stop the repeated interrupts.
@@ -785,6 +791,13 @@ static int oa_tc6_process_extended_status(struct oa_tc6 *tc6)
return ret;
}
+ /* This function is called for each chunk received in a given SPI
+ * transaction. In case, extended status bit is set in more than
+ * one chunk, skip the write, if status0 is already cleared.
+ */
+ if (!value)
+ return 0;
+
/* Clear the error interrupts status */
ret = oa_tc6_write_register(tc6, OA_TC6_REG_STATUS0, value);
if (ret) {
@@ -794,8 +807,7 @@ static int oa_tc6_process_extended_status(struct oa_tc6 *tc6)
}
if (FIELD_GET(OA_TC6_STATUS0_RX_BUFFER_OVERFLOW_ERROR, value)) {
- tc6->rx_buf_overflow = true;
- oa_tc6_cleanup_ongoing_rx_skb(tc6);
+ oa_tc6_look_for_new_frame(tc6);
net_err_ratelimited("%s: Receive buffer overflow error\n",
tc6->netdev->name);
return -EAGAIN;
@@ -821,6 +833,8 @@ static int oa_tc6_process_extended_status(struct oa_tc6 *tc6)
static int oa_tc6_process_rx_chunk_footer(struct oa_tc6 *tc6, u32 footer)
{
+ int ret = 0;
+
/* Process rx chunk footer for the following,
* 1. tx credits
* 2. errors if any from MAC-PHY
@@ -831,9 +845,11 @@ static int oa_tc6_process_rx_chunk_footer(struct oa_tc6 *tc6, u32 footer)
footer);
if (FIELD_GET(OA_TC6_DATA_FOOTER_EXTENDED_STS, footer)) {
- int ret = oa_tc6_process_extended_status(tc6);
-
- if (ret)
+ ret = oa_tc6_process_extended_status(tc6);
+ /* EAGAIN error is recoverable. Move on to check
+ * HEADER and SYNC errors before returning.
+ */
+ if (ret && ret != -EAGAIN)
return ret;
}
@@ -851,7 +867,7 @@ static int oa_tc6_process_rx_chunk_footer(struct oa_tc6 *tc6, u32 footer)
return -ENODEV;
}
- return 0;
+ return ret;
}
static void oa_tc6_submit_rx_skb(struct oa_tc6 *tc6)
@@ -876,13 +892,35 @@ static void oa_tc6_submit_rx_skb(struct oa_tc6 *tc6)
tc6->rx_skb = NULL;
}
-static void oa_tc6_update_rx_skb(struct oa_tc6 *tc6, u8 *payload, u8 length)
+/* On oversubscribed traffic condition, particularly with overwhelming rx
+ * buffer overflow errors, there could be data chunk loss. If tail + length
+ * goes beyond end pointer, that is an indication that the data chunk with
+ * end_valid bit is lost. Time to look for a data chunk with start_valid bit.
+ *
+ * If rx_skb is NULL, it is time to start looking for data chunk with
+ * start_bit.
+ */
+static int oa_tc6_update_rx_skb(struct oa_tc6 *tc6, u8 *payload, u8 length)
{
+ if (!tc6->rx_skb ||
+ skb_tailroom(tc6->rx_skb) < length) {
+ oa_tc6_look_for_new_frame(tc6);
+ return -EAGAIN;
+ }
+
memcpy(skb_put(tc6->rx_skb, length), payload, length);
+ return 0;
}
+/* On overwhelming rx buffer overflow errors, due to data chunk loss, it is
+ * possible that we get two data chunks with start_valid bit set, without
+ * end_valid bit set in between. In this case, rx_skb would have a valid
+ * buffer pointer. We should release, if a valid pointer is found before
+ * allocating a new one.
+ */
static int oa_tc6_allocate_rx_skb(struct oa_tc6 *tc6)
{
+ oa_tc6_cleanup_ongoing_rx_skb(tc6);
tc6->rx_skb = netdev_alloc_skb_ip_align(tc6->netdev, tc6->netdev->mtu +
ETH_HLEN + ETH_FCS_LEN);
if (!tc6->rx_skb) {
@@ -902,7 +940,9 @@ static int oa_tc6_prcs_complete_rx_frame(struct oa_tc6 *tc6, u8 *payload,
if (ret)
return ret;
- oa_tc6_update_rx_skb(tc6, payload, size);
+ ret = oa_tc6_update_rx_skb(tc6, payload, size);
+ if (ret)
+ return ret;
oa_tc6_submit_rx_skb(tc6);
@@ -917,22 +957,24 @@ static int oa_tc6_prcs_rx_frame_start(struct oa_tc6 *tc6, u8 *payload, u16 size)
if (ret)
return ret;
- oa_tc6_update_rx_skb(tc6, payload, size);
-
- return 0;
+ return oa_tc6_update_rx_skb(tc6, payload, size);
}
-static void oa_tc6_prcs_rx_frame_end(struct oa_tc6 *tc6, u8 *payload, u16 size)
+static int oa_tc6_prcs_rx_frame_end(struct oa_tc6 *tc6, u8 *payload, u16 size)
{
- oa_tc6_update_rx_skb(tc6, payload, size);
+ int ret;
- oa_tc6_submit_rx_skb(tc6);
+ ret = oa_tc6_update_rx_skb(tc6, payload, size);
+ if (!ret)
+ oa_tc6_submit_rx_skb(tc6);
+ return ret;
}
-static void oa_tc6_prcs_ongoing_rx_frame(struct oa_tc6 *tc6, u8 *payload,
- u32 footer)
+static int oa_tc6_prcs_ongoing_rx_frame(struct oa_tc6 *tc6, u8 *payload,
+ u32 footer)
{
- oa_tc6_update_rx_skb(tc6, payload, OA_TC6_CHUNK_PAYLOAD_SIZE);
+ return oa_tc6_update_rx_skb(tc6, payload,
+ OA_TC6_CHUNK_PAYLOAD_SIZE);
}
static int oa_tc6_prcs_rx_chunk_payload(struct oa_tc6 *tc6, u8 *data,
@@ -947,10 +989,10 @@ static int oa_tc6_prcs_rx_chunk_payload(struct oa_tc6 *tc6, u8 *data,
u16 size;
/* Restart the new rx frame after receiving rx buffer overflow error */
- if (start_valid && tc6->rx_buf_overflow)
- tc6->rx_buf_overflow = false;
+ if (start_valid && tc6->wait_until_start_valid)
+ tc6->wait_until_start_valid = false;
- if (tc6->rx_buf_overflow)
+ if (tc6->wait_until_start_valid)
return 0;
/* Process the chunk with complete rx frame */
@@ -972,8 +1014,7 @@ static int oa_tc6_prcs_rx_chunk_payload(struct oa_tc6 *tc6, u8 *data,
/* Process the chunk with only rx frame end */
if (end_valid && !start_valid) {
size = end_byte_offset + 1;
- oa_tc6_prcs_rx_frame_end(tc6, data, size);
- return 0;
+ return oa_tc6_prcs_rx_frame_end(tc6, data, size);
}
/* Process the chunk with previous rx frame end and next rx frame
@@ -987,6 +1028,15 @@ static int oa_tc6_prcs_rx_chunk_payload(struct oa_tc6 *tc6, u8 *data,
if (tc6->rx_skb) {
size = end_byte_offset + 1;
oa_tc6_prcs_rx_frame_end(tc6, data, size);
+
+ /* Return value from oa_tc6_prcs_rx_frame_end is not
+ * checked. If it returned an error, it is to make
+ * the code to look for new frame. At this stage,
+ * code below is going to process a new frame. So,
+ * error condition is set to false, in case it is
+ * set before proceeding.
+ */
+ tc6->wait_until_start_valid = false;
}
size = OA_TC6_CHUNK_PAYLOAD_SIZE - start_byte_offset;
return oa_tc6_prcs_rx_frame_start(tc6,
@@ -995,9 +1045,7 @@ static int oa_tc6_prcs_rx_chunk_payload(struct oa_tc6 *tc6, u8 *data,
}
/* Process the chunk with ongoing rx frame data */
- oa_tc6_prcs_ongoing_rx_frame(tc6, data, footer);
-
- return 0;
+ return oa_tc6_prcs_ongoing_rx_frame(tc6, data, footer);
}
static u32 oa_tc6_get_rx_chunk_footer(struct oa_tc6 *tc6, u16 footer_offset)
@@ -1013,8 +1061,9 @@ static u32 oa_tc6_get_rx_chunk_footer(struct oa_tc6 *tc6, u16 footer_offset)
static int oa_tc6_process_spi_data_rx_buf(struct oa_tc6 *tc6, u16 length)
{
u16 no_of_rx_chunks = length / OA_TC6_CHUNK_SIZE;
+ bool retry = false;
+ int ret = 0;
u32 footer;
- int ret;
/* All the rx chunks in the receive SPI data buffer are examined here */
for (int i = 0; i < no_of_rx_chunks; i++) {
@@ -1023,8 +1072,11 @@ static int oa_tc6_process_spi_data_rx_buf(struct oa_tc6 *tc6, u16 length)
OA_TC6_CHUNK_PAYLOAD_SIZE);
ret = oa_tc6_process_rx_chunk_footer(tc6, footer);
- if (ret)
- return ret;
+ if (ret) {
+ if (ret != -EAGAIN)
+ return ret;
+ retry = true;
+ }
/* If there is a data valid chunks then process it for the
* information needed to determine the validity and the location
@@ -1036,12 +1088,35 @@ static int oa_tc6_process_spi_data_rx_buf(struct oa_tc6 *tc6, u16 length)
ret = oa_tc6_prcs_rx_chunk_payload(tc6, payload,
footer);
- if (ret)
- return ret;
+ if (ret) {
+ if (ret != -ENOMEM && ret != -EAGAIN)
+ return ret;
+ retry = true;
+ }
}
}
- return 0;
+ /* Not bailing out on recoverable error codes, -EAGAIN and
+ * -ENOMEM. If subsequent loop iterations, if any, succeeds,
+ * error code would be overwritten. retry flag helps to
+ * make the caller to continue and retry. Since recovery
+ * action for -ENOMEM and -EAGAIN are same, we are returning
+ * one of the error codes, that is -EAGAIN.
+ *
+ * Successful recovery depends on how small the frames are,
+ * how many chunks, among the received chunks triggered the
+ * error, whether data is intact even with error conditions.
+ * As a result, there is no single, best method to recover
+ * most data when error conditions hit. We do our best by
+ * processing all the chunks with good "footer header" and
+ * "data valid" bit set.
+ */
+ if (retry) {
+ ret = -EAGAIN;
+ oa_tc6_look_for_new_frame(tc6);
+ }
+
+ return ret;
}
static __be32 oa_tc6_prepare_data_header(bool data_valid, bool start_valid,
@@ -1203,10 +1278,8 @@ static int oa_tc6_try_spi_transfer(struct oa_tc6 *tc6)
}
ret = oa_tc6_process_spi_data_rx_buf(tc6, spi_len);
- if (ret) {
- if (ret == -EAGAIN)
- continue;
+ if (ret && ret != -EAGAIN) {
oa_tc6_free_ongoing_skbs(tc6);
netdev_err(tc6->netdev, "Device error: %d\n", ret);
return ret;
--
2.43.0
^ permalink raw reply [flat|nested] 6+ messages in thread