+ Tim K (reporter) Hi Tim, Could you please try this patch can help your rtw8822bu? Ping-Ke Shih <pkshih@xxxxxxxxxxx> wrote: > Kalle Valo <kvalo@xxxxxxxxxx> wrote: > > marcin.slusarz@xxxxxxxxx writes: > > > > > From: Marcin Ślusarz <mslusarz@xxxxxxxxx> > > > > > > Right now it's possible to hit NULL pointer dereference in > > > rtw_rx_fill_rx_status on hw object and/or its fields because > > > initialization routine can start getting USB replies before > > > rtw_dev is fully setup. > > > > > > The stack trace looks like this: > > > > > > rtw_rx_fill_rx_status > > > rtw8821c_query_rx_desc > > > rtw_usb_rx_handler > > > ... > > > queue_work > > > rtw_usb_read_port_complete > > > ... > > > usb_submit_urb > > > rtw_usb_rx_resubmit > > > rtw_usb_init_rx > > > rtw_usb_probe > > > > > > So while we do the async stuff rtw_usb_probe continues and calls > > > rtw_register_hw, which does all kinds of initialization (e.g. > > > via ieee80211_register_hw) that rtw_rx_fill_rx_status relies on. > > > > > > Fix this by moving the first usb_submit_urb after everything > > > is set up. > > > > > > For me, this bug manifested as: > > > [ 8.893177] rtw_8821cu 1-1:1.2: band wrong, packet dropped > > > [ 8.910904] rtw_8821cu 1-1:1.2: hw->conf.chandef.chan NULL in rtw_rx_fill_rx_status > > > because I'm using Larry's backport of rtw88 driver with the NULL > > > checks in rtw_rx_fill_rx_status. > > > > > > This should fix: > > > https://marc.info/?l=linux-wireless&m=167907688311943&w=2 > > > > Please use permalinks from lore.kernel.org, marc links don't contain the > > Message-Id and are hence unreliable. > > > > Use tags below: > > Reported-by: Tim K <tpkuester@xxxxxxxxx> > Closes: > https://lore.kernel.org/linux-wireless/CA+shoWQ7P49jhQasofDcTdQhiuarPTjYEDa--NiVVx494WcuQw@mail.gmail. > com/ >