[PATCH net] dpaa2-switch: Fix error checking in dpaa2_switch_seed_bp()

[PATCH net] dpaa2-switch: Fix error checking in dpaa2_switch_seed_bp()

[Dan Carpenter]

The dpaa2_switch_add_bufs() function returns the number of bufs that it
was able to add.  It returns BUFS_PER_CMD (7) for complete success or a
smaller number if there are not enough pages available.  However, the
error checking is looking at the total number of bufs instead of the
number which were added on this iteration.  Thus the error checking
only works correctly for the first iteration through the loop and
subsequent iterations are always counted as a success.

Fix this by checking only the bufs added in the current iteration.

Fixes: 0b1b71370458 ("staging: dpaa2-switch: handle Rx path on control interface")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
From reviewing the code.  Not tested.
---
 drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
index a71f848adc05..a293b08f36d4 100644
--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
+++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c
@@ -2638,13 +2638,14 @@ static int dpaa2_switch_refill_bp(struct ethsw_core *ethsw)
 
 static int dpaa2_switch_seed_bp(struct ethsw_core *ethsw)
 {
-	int *count, i;
+	int *count, ret, i;
 
 	for (i = 0; i < DPAA2_ETHSW_NUM_BUFS; i += BUFS_PER_CMD) {
+		ret = dpaa2_switch_add_bufs(ethsw, ethsw->bpid);
 		count = &ethsw->buf_count;
-		*count += dpaa2_switch_add_bufs(ethsw, ethsw->bpid);
+		*count += ret;
 
-		if (unlikely(*count < BUFS_PER_CMD))
+		if (unlikely(ret < BUFS_PER_CMD))
 			return -ENOMEM;
 	}
 
-- 
2.43.0

Re: [PATCH net] dpaa2-switch: Fix error checking in dpaa2_switch_seed_bp()

[Simon Horman]

On Sat, Aug 17, 2024 at 09:52:46AM +0300, Dan Carpenter wrote:
> The dpaa2_switch_add_bufs() function returns the number of bufs that it
> was able to add.  It returns BUFS_PER_CMD (7) for complete success or a
> smaller number if there are not enough pages available.  However, the
> error checking is looking at the total number of bufs instead of the
> number which were added on this iteration.  Thus the error checking
> only works correctly for the first iteration through the loop and
> subsequent iterations are always counted as a success.
> 
> Fix this by checking only the bufs added in the current iteration.
> 
> Fixes: 0b1b71370458 ("staging: dpaa2-switch: handle Rx path on control interface")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> ---
> >From reviewing the code.  Not tested.

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH net] dpaa2-switch: Fix error checking in dpaa2_switch_seed_bp()

[Ioana Ciornei]

On Sat, Aug 17, 2024 at 09:52:46AM +0300, Dan Carpenter wrote:
> The dpaa2_switch_add_bufs() function returns the number of bufs that it
> was able to add.  It returns BUFS_PER_CMD (7) for complete success or a
> smaller number if there are not enough pages available.  However, the
> error checking is looking at the total number of bufs instead of the
> number which were added on this iteration.  Thus the error checking
> only works correctly for the first iteration through the loop and
> subsequent iterations are always counted as a success.
> 
> Fix this by checking only the bufs added in the current iteration.
> 
> Fixes: 0b1b71370458 ("staging: dpaa2-switch: handle Rx path on control interface")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>

Thanks,
Ioana

Re: [PATCH net] dpaa2-switch: Fix error checking in dpaa2_switch_seed_bp()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Sat, 17 Aug 2024 09:52:46 +0300 you wrote:
> The dpaa2_switch_add_bufs() function returns the number of bufs that it
> was able to add.  It returns BUFS_PER_CMD (7) for complete success or a
> smaller number if there are not enough pages available.  However, the
> error checking is looking at the total number of bufs instead of the
> number which were added on this iteration.  Thus the error checking
> only works correctly for the first iteration through the loop and
> subsequent iterations are always counted as a success.
> 
> [...]

Here is the summary with links:
  - [net] dpaa2-switch: Fix error checking in dpaa2_switch_seed_bp()
    https://git.kernel.org/netdev/net/c/c50e7475961c

You are awesome, thank you!
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