2018-05-06 13:26:00

by Erik Stromdahl

[permalink] [raw]
Subject: [PATCH] ath10k: fix return value check in wake_tx_q op

ath10k_mac_tx_push_txq returns either a postive integer (length) on
success or a negative error code on error.

The "if (ret) break;" statement will thus always break out of the loop
immediately after ath10k_mac_tx_push_txq has returned (making the loop
pointless).

A side effect of this fix is that we will iterate the queue until
ath10k_mac_tx_push_txq returns -ENOENT. This will make sure the queue is
not added back to ar->txqs when it is empty. This could potentially
improve performance somewhat (I have seen a small improvement with SDIO
devices).

Signed-off-by: Erik Stromdahl <[email protected]>
---
drivers/net/wireless/ath/ath10k/mac.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 3d7119ad7c7a..487a7a7380fd 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -4290,7 +4290,7 @@ static void ath10k_mac_op_wake_tx_queue(struct ieee80211_hw *hw,

while (ath10k_mac_tx_can_push(hw, f_txq) && max--) {
ret = ath10k_mac_tx_push_txq(hw, f_txq);
- if (ret)
+ if (ret < 0)
break;
}
if (ret != -ENOENT)
--
2.17.0


2018-05-12 09:03:32

by Kalle Valo

[permalink] [raw]
Subject: Re: ath10k: fix return value check in wake_tx_q op

Erik Stromdahl <[email protected]> wrote:

> ath10k_mac_tx_push_txq returns either a postive integer (length) on
> success or a negative error code on error.
>
> The "if (ret) break;" statement will thus always break out of the loop
> immediately after ath10k_mac_tx_push_txq has returned (making the loop
> pointless).
>
> A side effect of this fix is that we will iterate the queue until
> ath10k_mac_tx_push_txq returns -ENOENT. This will make sure the queue is
> not added back to ar->txqs when it is empty. This could potentially
> improve performance somewhat (I have seen a small improvement with SDIO
> devices).
>
> Signed-off-by: Erik Stromdahl <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>

Patch applied to ath-next branch of ath.git, thanks.

e3148cc5fecf ath10k: fix return value check in wake_tx_q op

--
https://patchwork.kernel.org/patch/10382789/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches