[PATCH net] net: ethernet: sunplus: check budget before calling napi_complete_done()

[PATCH net] net: ethernet: sunplus: check budget before calling napi_complete_done()

[Janis Edvarts Lacis]

Sunplus drivers currently do napi_complete() after each rx/tx poll is
done without checking whether budget was exhausted or not. Interrupts
are also unmasked before the call to napi_complete().

Replace napi_complete() with napi_complete_done() and add a check for
budget_left. Call napi_complete_done() only when the budget has been
not exhausted fully, e.g. budget_left > 0 and unmask interrupts only when
napi_complete_done() returns true.

I do not have the hardware necessary, this patch is not tested on real
hardware.

Fixes: fd3040b9394c ("net: ethernet: Add driver for Sunplus SP7021")
Signed-off-by: Janis Edvarts Lacis <janislacis06@gmail.com>
---
 drivers/net/ethernet/sunplus/spl2sw_int.c | 26 ++++++++++++-----------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/sunplus/spl2sw_int.c b/drivers/net/ethernet/sunplus/spl2sw_int.c
index a37c9a4c281f..1aada11429d4 100644
--- a/drivers/net/ethernet/sunplus/spl2sw_int.c
+++ b/drivers/net/ethernet/sunplus/spl2sw_int.c
@@ -125,13 +125,14 @@ int spl2sw_rx_poll(struct napi_struct *napi, int budget)
 			h_desc = comm->rx_desc[queue] + rx_pos;
 	}
 
-	spin_lock_irqsave(&comm->int_mask_lock, flags);
-	mask = readl(comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
-	mask &= ~MAC_INT_RX;
-	writel(mask, comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
-	spin_unlock_irqrestore(&comm->int_mask_lock, flags);
+	if (budget_left > 0 && napi_complete_done(napi, budget - budget_left)) {
+		spin_lock_irqsave(&comm->int_mask_lock, flags);
+		mask = readl(comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
+		mask &= ~MAC_INT_RX;
+		writel(mask, comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
+		spin_unlock_irqrestore(&comm->int_mask_lock, flags);
+	}
 
-	napi_complete(napi);
 	return budget - budget_left;
 }
 
@@ -198,13 +199,14 @@ int spl2sw_tx_poll(struct napi_struct *napi, int budget)
 
 	spin_unlock(&comm->tx_lock);
 
-	spin_lock_irqsave(&comm->int_mask_lock, flags);
-	mask = readl(comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
-	mask &= ~MAC_INT_TX;
-	writel(mask, comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
-	spin_unlock_irqrestore(&comm->int_mask_lock, flags);
+	if (budget_left > 0 && napi_complete_done(napi, budget - budget_left)) {
+		spin_lock_irqsave(&comm->int_mask_lock, flags);
+		mask = readl(comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
+		mask &= ~MAC_INT_TX;
+		writel(mask, comm->l2sw_reg_base + L2SW_SW_INT_MASK_0);
+		spin_unlock_irqrestore(&comm->int_mask_lock, flags);
+	}
 
-	napi_complete(napi);
 	return budget - budget_left;
 }
 
-- 
2.43.0

Re: [PATCH net] net: ethernet: sunplus: check budget before calling napi_complete_done()

[Andrew Lunn]

On Sun, Nov 15, 2026 at 12:27:44AM +0200, Janis Edvarts Lacis wrote:
> Sunplus drivers currently do napi_complete() after each rx/tx poll is
> done without checking whether budget was exhausted or not. Interrupts
> are also unmasked before the call to napi_complete().
> 
> Replace napi_complete() with napi_complete_done() and add a check for
> budget_left. Call napi_complete_done() only when the budget has been
> not exhausted fully, e.g. budget_left > 0 and unmask interrupts only when
> napi_complete_done() returns true.
> 
> I do not have the hardware necessary, this patch is not tested on real
> hardware.
> 
> Fixes: fd3040b9394c ("net: ethernet: Add driver for Sunplus SP7021")
> Signed-off-by: Janis Edvarts Lacis <janislacis06@gmail.com>

Does this bother anybody? If not, net-next. No Fixes: tag.

Given that you have not tested this, how confident are you it is
correct?

	Andrew

Re: [PATCH net] net: ethernet: sunplus: check budget before calling napi_complete_done()

[netdev-bot+sinfo]

Hi!

This is an automated message. This series looks like a fix, but its
commit messages seem to be missing some information:

 - How the issue was discovered, e.g. hit in production, hit during
   development, syzbot report, manual code inspection, LLM or static
   analysis tool scan.

Please do not repost the series just to address the above. Instead,
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-- 
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