On Tue, May 17, 2016 at 01:22:52PM +0300, Imre Deak wrote: > On ti, 2016-05-17 at 11:59 +0200, Takashi Iwai wrote: > > On Tue, 17 May 2016 11:42:17 +0200, > > Daniel Vetter wrote: > > > > > > On Tue, May 17, 2016 at 09:37:12AM +0200, Takashi Iwai wrote: > > > > On Tue, 17 May 2016 09:20:48 +0200, > > > > Daniel Vetter wrote: > > > > > > > > > > On Thu, May 12, 2016 at 09:06:53PM +0300, Imre Deak wrote: > > > > > > User may pass nomodeset or i915.modeset=0 option to disable i915 KMS > > > > > > explicitly. Although this itself works fine, it breaks the weak > > > > > > dependency the HD-audio driver requires, and it's the reason the > > > > > > delayed component binding isn't implemented in HD-audio. Since i915 > > > > > > doesn't notify its disablement, HD-audio would be blocked > > > > > > unnecessarily endlessly, waiting for the bind with i915. > > > > > > > > > > > > This patch introduces a stub audio component binding when i915 driver > > > > > > is loaded with KMS off like the boot options above. Then i915 driver > > > > > > still registers the slave component but with the new "disabled" ops > > > > > > flag, so that the master component (HD-audio) can know clearly the > > > > > > slave state. > > > > > > > > > > > > v2: > > > > > > - Fail the probe in case component registration fails, instead of > > > > > > suppressing the error. (Ville) > > > > > > - Register the component only for the real PCI device function. > > > > > > > > > > > > CC: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > > > > > Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> > > > > > > Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> > > > > > > > > > > We don't support not running with modesetting. Why do we suddenly care? > > > > > > > > This is needed for the patch 2 and 3. Right now we have no blocking > > > > or deferred component binding, so far, in HD-audio side. This caused > > > > problems when async module probe was done. > > > > > > > > So, the patch 3 implements the blocking behavior of HD-audio side. It > > > > would lead to another regression when i915 doesn't notify its disabled > > > > state by this patch. Otherwise the HD-audio driver will be blocked > > > > endlessly of unnecessarily long. > > > > > > > > > Same for users creating a .config that fails to boot or work ... > > > > > > > > The config isn't cared much, but the problem is about the runtime boot > > > > option. > > > > > > > > > If HDA needs to coporate with gfx to get things done, then imo we should > > > > > just require that i915.ko is there. > > > > > > > > Other way round: we do already require i915 in HD-audio side. But in > > > > this case, we do *not* want to require i915 when it's disabled in > > > > runtime. > > > > > > That's what I mean: If you boot with i915.nomodeset you're explicitly fine > > > with a somewhat non-useable system - that option is for debugging only > > > really. If that means audio also doesn't work, then I think that's ok. > > > > It's not only "it doesn't work". The module load gets stuck. So we > > need some notification for the blocked component binding. > > > > > Adding complexity for this case (which means more error paths we don't > > > ever test and hence _will_ break) seems over the top. > > > > > > I'm quite opposed to adding error handling for every condition in general > > > because the combinatorial testing madness just can't be handled. The one > > > exception in the i915.ko driver is that when the render side died > > > (terminal gpu hang) we'll try our best to keep the display alive. But > > > that's it, and the justification for that is "we want users to be able to > > > get the bug report out". I don't see a justification of that magnitude for > > > this feature here at all. > > > > Well, actually the patchset was proposed just because Intel CI tests > > failed due to async module probes. If Intel is happy with continued > > CI test failures, I'm also happy with the current situation ;) > > It's not only due to those particular failures. That was caused by a > kmod bug and as such would be good to not depend on that mechanism. But > things will fail atm even in the normal case when audio is built-in and > i915 is a module. This patchset would solve that too. I'm not against patch 3 from this series, which seems to be the bugfix we want. I'm against the kludge in patch 1 here only (and maybe patch 2, not sure about that). Patch 1 here looks like a workaround purely for the i915.modeset=0 case. And I don't want special code for debug knobs if we can avoid it. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
