Hi Jonathan,
On Tue, Jul 13, 2021 at 01:13:03PM +1000, Jonathan Gray wrote:
> On Mon, Jul 12, 2021 at 06:22:36PM +0000, Tom Murphy wrote:
> > I had firefox open (various tabs/windows) and was playing a 3D game
> > (games/quakespasm) and after a random amount of time I got a hard lock up,
> > but the second time it happened I was able to get into a ddb prompt. I've
> > added the panic message and trace and dmesg.
> >
> > I don't have a serial console on this laptop so had to transcribe this by
> > hand from a photo I took on my phone. (Is there an easier way to save
> > these?)
>
> It is possible to get a trace out of a crash dump, see crash(8).
> But yes serial or amt sol is easier.
Thanks! I'll have a closer look at crash(8).
> > panic: kernel diagnostic assertion "to_ticks >= 0" failed: file
> > "/usr/src/sys/kern/kern_timeout.c", line 299
> > Stopped at db_enter+0x10: popq %rbp
> > TID PID UID PRFLAGS PFLAGS CPU COMMAND
> > *395451 18070 0 0x14000 0x200 0K drmtskl
> > 61931 46160 0 0x14000 0x200 2 drmwq
> > 185485 53694 0 0x14000 0x200 1 drmwq
> > 284820 77991 0 0x14000 0x200 3 drmwq
> > db_enter() at db_enter+0x10
> > panic(ffffffff81e5f243) at panic+0xbf
> > __assert(ffffffff81ec940a,ffffffff81eb2a3e,12b,ffffffff81ec1795) at
> > __assert+0x2b
> > timeout_add(ffff800000bf0410,ffffffff) at timeout_add+0x1cc
> > process_csb(ffff800000bf0000) at process_csb+0x38b
> > execlists_submission_tasklet(ffff800000bf0000) at
> > execlists_submission_tasklet+0x48
> > tasklet_run(ffff800000bf03c0) at tasklet_run+0x44
> > taskq_thread(ffff800000220f00) at taskq_thread+0x81
> > end trace frame: 0x0, count: 7
>
> The timeout_add() call comes from i915_utils.c set_timer_ms()
> mod_timer(t, jiffies + timeout ?: 1);
>
> can you try this patch?
>
> Index: sys/dev/pci/drm/include/linux/timer.h
> ===================================================================
> RCS file: /cvs/src/sys/dev/pci/drm/include/linux/timer.h,v
> retrieving revision 1.6
> diff -u -p -r1.6 timer.h
> --- sys/dev/pci/drm/include/linux/timer.h 7 Jul 2021 02:38:36 -0000
> 1.6
> +++ sys/dev/pci/drm/include/linux/timer.h 13 Jul 2021 02:54:26 -0000
> @@ -24,10 +24,20 @@
> #include <sys/kernel.h>
> #include <linux/ktime.h>
>
> -#define mod_timer(x, y) timeout_add((x), ((y) - jiffies))
> #define del_timer_sync(x) timeout_del_barrier((x))
> #define del_timer(x) timeout_del((x))
> #define timer_pending(x) timeout_pending((x))
> +
> +static inline int
> +mod_timer(struct timeout *to, unsigned long j)
> +{
> + int ticks = j - jiffies;
> + if (ticks <= 0) {
> + timeout_del(to);
> + return timeout_add(to, 1);
> + }
> + return timeout_add(to, ticks);
> +}
>
> static inline unsigned long
> round_jiffies_up(unsigned long j)
This patch seems to work for me. I did some pretty rigorous testing
with it and attempted to recreate the same conditions that made it
crash however I wasn't able to get the kernel panic so that is a good
sign!
Thanks,
Tom
