2017-12-09 00:35:16

by Bjorn Andersson

Subject: [PATCH] wcn36xx: Reduce spinlock in indication handler

The purpose of pushing indication on a list and handle these in a
separate worker is to allow the handlers to sleep. It does therefor not
make much sense to hold the queue spinlock through the entire indication
worker function.

By removing items from the queue early we don't need to hold the lock
throughout the indication worker, allowing the individual handlers to
sleep.

Signed-off-by: Bjorn Andersson <[email protected]>
---
drivers/net/wireless/ath/wcn36xx/smd.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/wcn36xx/smd.c b/drivers/net/wireless/ath/wcn36xx/smd.c
index fa88a2a460aa..52daae863aed 100644
--- a/drivers/net/wireless/ath/wcn36xx/smd.c
+++ b/drivers/net/wireless/ath/wcn36xx/smd.c
@@ -2414,6 +2414,8 @@ static void wcn36xx_ind_smd_work(struct work_struct *work)
hal_ind_msg = list_first_entry(&wcn->hal_ind_queue,
struct wcn36xx_hal_ind_msg,
list);
+ list_del(wcn->hal_ind_queue.next);
+ spin_unlock_irqrestore(&wcn->hal_ind_lock, flags);

msg_header = (struct wcn36xx_hal_msg_header *)hal_ind_msg->msg;

@@ -2450,8 +2452,6 @@ static void wcn36xx_ind_smd_work(struct work_struct *work)
wcn36xx_err("SMD_EVENT (%d) not supported\n",
msg_header->msg_type);
}
- list_del(wcn->hal_ind_queue.next);
- spin_unlock_irqrestore(&wcn->hal_ind_lock, flags);
kfree(hal_ind_msg);
}
int wcn36xx_smd_open(struct wcn36xx *wcn)
--
2.15.0

2017-12-14 15:32:39

by Kalle Valo

Subject: Re: wcn36xx: Reduce spinlock in indication handler

Bjorn Andersson <[email protected]> wrote:

> The purpose of pushing indication on a list and handle these in a
> separate worker is to allow the handlers to sleep. It does therefor not
> make much sense to hold the queue spinlock through the entire indication
> worker function.
>
> By removing items from the queue early we don't need to hold the lock
> throughout the indication worker, allowing the individual handlers to
> sleep.
>
> Signed-off-by: Bjorn Andersson <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>

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

6d1f37323f5b wcn36xx: Reduce spinlock in indication handler

--
https://patchwork.kernel.org/patch/10103469/

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