Add more. On Mon, Sep 18, 2023 at 1:22 PM xingxing luo <xingxing0070.luo@xxxxxxxxx> wrote: > > On Fri, Sep 15, 2023 at 4:48 PM Sergey Shtylyov <s.shtylyov@xxxxxx> wrote: > > > > On 9/15/23 5:59 AM, xingxing luo wrote: > > [...] > > > > >>> When multiple threads are performing USB transmission, musb->lock will be > > >>> unlocked when musb_giveback is executed. At this time, qh may be released > > >>> in the dequeue process in other threads, resulting in a wild pointer, so > > >>> it needs to be here get qh again, and judge whether qh is NULL, and when > > >>> dequeue, you need to set qh to NULL. > > >>> > > >>> Fixes: dbac5d07d13e ("usb: musb: host: don't start next rx urb if current one failed") > > >>> Signed-off-by: Xingxing Luo <xingxing.luo@xxxxxxxxxx> > > >>> --- > > >>> drivers/usb/musb/musb_host.c | 9 ++++++++- > > >>> 1 file changed, 8 insertions(+), 1 deletion(-) > > >>> > > >>> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c > > >>> index a02c29216955..9df27db5847a 100644 > > >>> --- a/drivers/usb/musb/musb_host.c > > >>> +++ b/drivers/usb/musb/musb_host.c > > >>> @@ -321,10 +321,16 @@ static void musb_advance_schedule(struct musb *musb, struct urb *urb, > > >>> musb_giveback(musb, urb, status); > > >>> qh->is_ready = ready; > > >>> > > >>> + /* > > >>> + * musb->lock had been unlocked in musb_giveback, so somtimes qh > > >> > > >> Sometimes? > > > > You have a typo... > > > > >> > > >>> + * may freed, need get it again > > >>> + */ > > >>> + qh = musb_ep_get_qh(hw_ep, is_in); > > >>> + > > >>> /* reclaim resources (and bandwidth) ASAP; deschedule it, and > > >>> * invalidate qh as soon as list_empty(&hep->urb_list) > > >>> */ > > >>> - if (list_empty(&qh->hep->urb_list)) { > > >>> + if (qh != NULL && list_empty(&qh->hep->urb_list)) { > > >> > > >> Just qh, perhaps? > > > > > > Could you elaborate a little more? > > > Thanks. > > > > Just 'qh' gives you the same as 'qh != NULL'. > > Ok, I will address this in the next version. > > > > > [...] > > > > MBR, Sergey B.R Xingxing.Luo