On Wed, Jul 16, 2014 at 06:19:13PM -0300, Paulo Zanoni wrote: > 2014-07-14 14:34 GMT-03:00 Daniel Vetter <daniel@xxxxxxxx>: > > On Mon, Jul 14, 2014 at 11:56:57AM -0300, Paulo Zanoni wrote: > >> 2014-07-07 18:53 GMT-03:00 Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>: > >> > On Mon, 7 Jul 2014 18:48:47 -0300 > >> > Paulo Zanoni <przanoni@xxxxxxxxx> wrote: > >> > > >> >> (documenting what we discussed on IRC) > >> >> > >> >> 2014-06-20 13:29 GMT-03:00 Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>: > >> >> > This was always the case on our suspend path, but it was recently > >> >> > exposed by the change to use our runtime IRQ disable routine rather than > >> >> > the full DRM IRQ disable. Keep the warning on the enable side, as that > >> >> > really would indicate a bug. > >> >> > >> >> While I understand the patch and think it's a reasonable thing to do, > >> >> I feel the need to spend some time persuading you in replacing it with > >> >> something that doesn't involve removing WARNs from our driver. While > >> >> the driver is runtime suspended, no one should really be manipulating > >> >> IRQs, even if they're disabling stuff that is already disabled: this > >> >> reflects there's probably a problem somewhere. These WARNs are > >> >> extremely helpful for the runtime PM feature because almost nobody > >> >> actually uses runtime PM to notice any bugs with it, so the WARNs can > >> >> make QA report bugs and bisect things for us. > >> >> > >> >> Also, it seems S3 suspend is currently a little disaster on our > >> >> driver. Your 6 patches just solve some of the WARNs, not all of them. > >> >> And last week I even solved another WARN on the S3 path. I just did > >> >> some investigation, and the current bad commits are: > >> >> 8abdc17941c71b37311bb93876ac83dce58160c8, > >> >> e11aa362308f5de467ce355a2a2471321b15a35c and > >> >> 85e90679335f56d162f4a0ff525573818e17ce44. If I just revert these 3 > >> >> commits, S3 doesn't give me any WARNs. > >> >> > >> >> Instead of the change you proposed, can't we think of another solution > >> >> that would maybe address all the 3 regressions we have? Since we're > >> >> always submitting patches to change the order we do things at S3 > >> >> suspend/resume, shouldn't we add something like "dev_priv->suspending" > >> >> that could be used to avoid the strict ordering that is required > >> >> during runtime? > >> > > >> > Hm I was running with those changes and didn't see additional warnings, > >> > so I'll have to look again. > >> > > >> > I agree we want sensible warnings in place, and maybe removing this one > >> > is too permissive, but I'd like to avoid a suspending flag if we can. > >> > > >> > Maybe we just need to bundle up our assertions and check all the > >> > relevant state after runtime suspend or S3 like we do for mode set > >> > state in various places. That would let us keep our warnings, but also > >> > save us from having them spread out in code paths that get used in > >> > many different contexts. > >> > >> I'm probably going to regret this, but since no one proposed a better > >> patch and the bug is still there: > >> Reviewed-by: Paulo Zanoni <paulo.r.zanoni@xxxxxxxxx> > > > > Not really eager to merge a patch soaking in preemptive regrets ... > > > > I'll punt on this for now. > > Possible solutions: > > 1 - Patch xxx_disable_vblank to do nothing in case dev_priv->pm.suspended > 2 - Add a flag dev_priv->suspending and don't print those WARNs in > case it is set. > 3 - Merge Jesse's original patch > 4 - Something else? > > I can implement any of the proposed solutions if needed... I've gone with 3 for now. It sounds like we need to work with this code a bit more still until the best solution is clear. The patch at least addresses the WARN. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
