On Mon, 2019-08-19 at 09:05 +0000, Lisovskiy, Stanislav wrote:
On Mon, 2019-08-19 at 08:35 +0100, Peres, Martin wrote:
On 19/08/2019 10:23, Lisovskiy, Stanislav wrote:
On Wed, 2019-08-07 at 23:07 +0200, Daniel Vetter wrote:
So igt isn't valid userspace (it's just good testcases). Can we repro the same on real userspace? Does this work with real userspace? We've had userspace which tries to be clever and filters out what looks like redundant hotplug events. And then gets it wrong in cases like this.
Also, we've had forever an unconditional uevent on resume, exactly because anything could have changed. Did we loose this one on the way somewhere? Or maybe I misremember ...
If all we care about is resume re-adding that uncondtional uevent on resume is going to be a lot easier than this here. -Daniel
Sorry for long reply(was on vacation), that is a good question regarding reproducing this in real life scenario. My obvious guess was to suspend the machine and meanwhile change connected display to another one. However this situation seems to be already handled by kernel nicely(tried few times and we always get a hotplug event). So that edid change during suspend chamelium test case seems to be a bit different. I will talk to our guys who wrote this about what is the real life scenario for this, because I'm now curious as well.
Thanks Daniel for the feedback.
I also now wonder why our IGT test (chamelium-based) does not pass if a uevent is sent on resume automatically and all the test is expecting is a uevent...
Martin
In fact I was wrong - when it worked, it was using exactly those patches :). With clean drm-tip - it seems to work ocassionally and it doesn't update the actual display edid and other stuff, so even when displays are changed we still see the old info/edid from userspace.
We always get a hpd irq when suspend/resume however it doesn't always result in uevent being sent. So there is a real need in those patches.
Just decided to "ping" this discussion again. The issue is already some years old and still nothing is fixed. I do agree that may be something needs to be fixed/changed here in those patches, but something must be agreed at least I guess, as discussions themself do not fix bugs. Currently those patches address a particular issue which occurs, if display is changed during suspend. On ocassional basis, userspace might not get a hotplug event at all, causing different kind of problems(like wrong mode set on display or diaply not working at all). Also some kms_chamelium hotplug tests fail because of that.
- Stanislav
-Stanislav
Cheers, Daniel
> > > -Stanislav > > > > -Daniel > > > > > > > > Stanislav Lisovskiy (3): > > > drm: Add helper to compare edids. > > > drm: Introduce change counter to drm_connector > > > drm/i915: Send hotplug event if edid had changed. > > > > > > drivers/gpu/drm/drm_connector.c | 1 + > > > drivers/gpu/drm/drm_edid.c | 33 > > > ++++++++++++++++++++ > > > drivers/gpu/drm/drm_probe_helper.c | 29 > > > +++++++++++++++- > > > - > > > drivers/gpu/drm/i915/display/intel_dp.c | 16 > > > +++++++++- > > > drivers/gpu/drm/i915/display/intel_hdmi.c | 16 > > > ++++++++-- > > > drivers/gpu/drm/i915/display/intel_hotplug.c | 21 > > > ++++++++++ > > > --- > > > include/drm/drm_connector.h | 3 ++ > > > include/drm/drm_edid.h | 9 > > > ++++++ > > > 8 files changed, 117 insertions(+), 11 deletions(-) > > > > > > -- > > > 2.17.1 > > > > > > >
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