Re: Patch "wifi: mt76: Disable napi when removing device" has been added to the 6.18-stable tree

Re: Patch "wifi: mt76: Disable napi when removing device" has been added to the 6.18-stable tree

[Nicolas Cavallari]

This patch alone causes regressions on mt792x, please wait for this fix
to reach mainline before applying both:

https://lore.kernel.org/linux-wireless/20260728002048.19351-1-mikhail.v.gavrilov@gmail.com/T/#u

On 7/28/26 20:31, Sasha Levin wrote:
> This is a note to let you know that I've just added the patch titled
>
>     wifi: mt76: Disable napi when removing device
>
> to the 6.18-stable tree which can be found at:
>     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>
> The filename of the patch is:
>      wifi-mt76-disable-napi-when-removing-device.patch
> and it can be found in the queue-6.18 subdirectory.
>
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable@vger.kernel.org> know about it.
>
>
>
> commit ec85c41196070fef11374b2a774ece87083c8a84
> Author: Nicolas Cavallari <nicolas.cavallari@green-communications.fr>
> Date:   Wed Jul 8 16:43:47 2026 +0200
>
>     wifi: mt76: Disable napi when removing device
>     
>     [ Upstream commit 13b7e6a96a005c656d38f3da51581deaf9866375 ]
>     
>     Unloading the mt7915e module with a MT7916 triggers multiples WARN in
>     __netif_napi_del_locked() and in page_pool_disable_direct_recycling()
>     because the driver does not disable the napi before destroying it.
>     
>     This is troublesome since on MT7916 it is required to unload the module
>     and reinsert it with a different enable_6ghz parameter to change the
>     frequency.  The system generally becomes unstable after reinserting the
>     module.
>     
>     Fix it by disabling napi before deleting it.  Also, do not delete napi
>     on WED queues since napi is neither used nor initialized on them.
>     
>     Fixes: 17f1de56df05 ("mt76: add common code shared between multiple chipsets")
>     Signed-off-by: Nicolas Cavallari <nicolas.cavallari@green-communications.fr>
>     Link: https://patch.msgid.link/20260708144615.24092-1-nicolas.cavallari@green-communications.fr
>     Signed-off-by: Felix Fietkau <nbd@nbd.name>
>     Signed-off-by: Sasha Levin <sashal@kernel.org>
>
> diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
> index 9ef073c27f3096..f5b2c8996affd1 100644
> --- a/drivers/net/wireless/mediatek/mt76/dma.c
> +++ b/drivers/net/wireless/mediatek/mt76/dma.c
> @@ -1174,7 +1174,10 @@ void mt76_dma_cleanup(struct mt76_dev *dev)
>  	mt76_for_each_q_rx(dev, i) {
>  		struct mt76_queue *q = &dev->q_rx[i];
>  
> -		netif_napi_del(&dev->napi[i]);
> +		if (!mt76_queue_is_wed_rro(q)) {
> +			napi_disable(&dev->napi[i]);
> +			netif_napi_del(&dev->napi[i]);
> +		}
>  		mt76_dma_rx_cleanup(dev, q);
>  
>  		page_pool_destroy(q->page_pool);

Re: Patch "wifi: mt76: Disable napi when removing device" has been added to the 6.18-stable tree

[Sasha Levin]

> This patch alone causes regressions on mt792x, please wait for this fix
> to reach mainline before applying both:
> 
> https://lore.kernel.org/linux-wireless/20260728002048.19351-1-mikhail.v.gavrilov@gmail.com/T/#u

Thanks for the heads up. I've dropped the backport of 13b7e6a96a00 ("wifi:
mt76: Disable napi when removing device") from the queue - it was only
queued for 7.1 and 6.18 and it is gone from both, so nothing shipped to
users.

I'll pick it up again together with the mt792x follow-up fix once that one
lands in mainline.

-- 
Thanks,
Sasha

Re: Patch "wifi: mt76: Disable napi when removing device" has been added to the 6.18-stable tree

[Nicolas Cavallari]

Le 30/07/2026 à 04:40, Sasha Levin a écrit :
>> This patch alone causes regressions on mt792x, please wait for this fix
>> to reach mainline before applying both:
>>
>> https://lore.kernel.org/linux-wireless/20260728002048.19351-1-mikhail.v.gavrilov@gmail.com/T/#u
> 
> Thanks for the heads up. I've dropped the backport of 13b7e6a96a00 ("wifi:
> mt76: Disable napi when removing device") from the queue - it was only
> queued for 7.1 and 6.18 and it is gone from both, so nothing shipped to
> users.
> 
> I'll pick it up again together with the mt792x follow-up fix once that one
> lands in mainline.

The followup patch has been dropped and the former patch is being 
reverted, so you may stop waiting for it.

Re: Patch "wifi: mt76: Disable napi when removing device" has been added to the 6.18-stable tree

[Sasha Levin]

> The followup patch has been dropped and the former patch is being
> reverted, so you may stop waiting for it.

Good to know, thanks - I've dropped it from my list, so nothing is
waiting on the mt792x follow-up any more.

-- 
Thanks,
Sasha