Re: [PATCH v2] wifi: mt76: mt7921: Add PCIe AER handler support to prevent system crash

[Johannes Berg <johannes@sipsolutions.net>]

Hi,

So ... yeah it's your driver, and yes it's already at v2, but ... this
still seems very much papering over a problem?

On Wed, 2025-10-08 at 16:59 +0800, Mingyen Hsieh wrote:
> 
> Unable to handle kernel paging request at virtual address ffffffc01099eac0
> pc : mt76_dma_add_buf+0x124/0x188 [mt76]

Why does it even crash there?

> +++ b/drivers/net/wireless/mediatek/mt76/agg-rx.c
> @@ -96,6 +96,9 @@ mt76_rx_aggr_reorder_work(struct work_struct *work)
>  	struct sk_buff_head frames;
>  	int nframes;
>  
> +	if (atomic_read(&dev->bus_hung) == 1)
> +		return;

And how does sprinkling this "magic dust" all over even do anything?


This sounds a bit like the driver isn't able to deal with surprise
removal, what happens if you e.g. rmmod it while running traffic? I
believe the effect of the error recovery would be similar, if you don't
handle it, so are you sure there's not a completely different underlying
bug?

johannes