Hi Geert, IMHO - QEMU is irrelevant here. since I can do passthrough -- in fact -- many drivers do use timeout in .fb_sync e.g. i810fb_sync(), nouveau_fbcon_sync(), sm501fb_sync() etc.. I believe the correct behaviour should be a timeout wait instead of waiting indefinitely. - Tong On Wed, Feb 24, 2021 at 6:35 AM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote: > > Hi Tong, > > On Sun, Feb 21, 2021 at 1:05 AM Tong Zhang <ztong0001@xxxxxxxxx> wrote: > > On Sat, Feb 20, 2021 at 6:33 PM Randy Dunlap <rdunlap@xxxxxxxxxxxxx> wrote: > > > On 2/20/21 3:02 PM, Tong Zhang wrote: > > > > pm2fb_sync is called when doing /dev/fb read or write. > > > > The original pm2fb_sync wait indefinitely on hardware flags which can > > > > possibly stall kernel and make everything unresponsive. > > > > Instead of waiting indefinitely, we can timeout to give user a chance to > > > > get back control. > > > > > > Is this a real problem or theoretical? > > > Does someone still use this driver? > > > > I currently have this problem on my machine. > > I have submitted a revised patch -- which includes the console log. > > Your machine is "QEMU Standard"? > Can this happen on real hardware, too, or is this a deficiency in QEMU, > which should be fixed there? > > Gr{oetje,eeting}s, > > Geert > > -- > Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx > > In personal conversations with technical people, I call myself a hacker. But > when I'm talking to journalists I just say "programmer" or something like that. > -- Linus Torvalds _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel