On Wed, 2 Jan 2019 17:29:46 +0800 Chris Chiu <chiu@xxxxxxxxxxxx> wrote: > Happy New Year. > Sorry for bothering you guys again, I don't really want to make myself > a nuisance. > Is there any better idea for fixing this issue? I've already back ported this change into the kernel 4.18.17 and sent it to our customer for integration test - So far so good. Thanks, -Guang > > Chris > > On Mon, Dec 3, 2018 at 6:38 PM Chris Chiu <chiu@xxxxxxxxxxxx> wrote: > > > > On Fri, Nov 30, 2018 at 1:15 AM Guang Bai <guang.bai@xxxxxxxxx> > > wrote: > > > > > > On Thu, 29 Nov 2018 10:17:49 +0200 > > > Jani Nikula <jani.nikula@xxxxxxxxx> wrote: > > > > > > > On Wed, 28 Nov 2018, Guang Bai <guang.bai@xxxxxxxxx> wrote: > > > > > On some GEN9 platforms, slowly unplugging (wiggling) the HDMI > > > > > cable makes the kernel to believe the HDMI display is still > > > > > connected. This is because the HDMI DDC lines are > > > > > disconnected a little bit later after the hot-plug interrupt > > > > > triggered thus an immediate edid fetch can be made. This > > > > > problem has been identified by more than one customer > > > > > recently. Use digital port live states to authorize the edid > > > > > read at HDMI detection point will ensure most of the display > > > > > related software states updated and rest of them will be > > > > > renewed accordingly when the port is connected. > > > > > > > > > > v2: Fix the formatting issue > > > > > v3: Use digital port states to authorize the edid read > > > > > v4: Add comments on issue histories and rationale of the fix > > > > > (Chris W) > > > > > > > > You're not answering Chris Wilson's question. > > > > > > > > Why do you think the problems we've historically had with live > > > > status are no longer a problem? We've tried and reverted live > > > > status checks at least twice before because of regressions. Why > > > > do you think this time there won't be regressions? Why do you > > > > think this patch makes forward progress? > > > Jani, > > > I'm still new to kernel developments compared with all of you > > > working in this area for many years - Haven't got any feedbacks > > > on how exactly the HDMI live statue *not* fit for HDMI hot-plug > > > related port status checking, neither had time to track all > > > upstream bugzilla, plus not working directly with Intel OTC teams > > > - What are those failing cases/regressions you mentioned above? > > > - what were the kernel versions related with those developments? > > > - Given the fact i915 architecture and implementation are > > > constantly evolving - Should we re-visit those issues with > > > current kernel implementation? > > > - Fundamentally, do you think the edid fetch is still *valid* > > > when the HDMI is unplugged (status either from PCH or DE)? Or > > > other platform configurations may present more complexities such > > > as kvm switches are used along with HDMI? > > > Again, if you could provide me more historical issue details, I'd > > > like to have some reviews/re-investigation for those cases with > > > current 4.20 kernel. > > > Thanks, > > > -Guang > > > > Hi Jani, > > I don't know the history and what kind of painful regression > > that you had run into. Could you maybe provide a test plan or some > > test cases for the regression verification? I can follow steps to > > try to verify whether if the patch can work on all cases. > > > > Chris > > > > > > > > > > I've *repeatedly* said from the beginning that I am very > > > > sceptical of using live status because we've been burned by it > > > > so many times before. I don't much care to repeat this anymore. > > > > > > > > > > > > BR, > > > > Jani. > > > > > > > > > > > > > > > > > > Cc: Jani Nikula <jani.nikula@xxxxxxxxx> > > > > > Cc: Chris Chiu <chiu@xxxxxxxxxxxx> > > > > > Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > > > > > Signed-off-by: Guang Bai <guang.bai@xxxxxxxxx> > > > > > --- > > > > > drivers/gpu/drm/i915/intel_hdmi.c | 2 +- > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > > > diff --git a/drivers/gpu/drm/i915/intel_hdmi.c > > > > > b/drivers/gpu/drm/i915/intel_hdmi.c index e2c6a2b..8cf7c78 > > > > > 100644 --- a/drivers/gpu/drm/i915/intel_hdmi.c > > > > > +++ b/drivers/gpu/drm/i915/intel_hdmi.c > > > > > @@ -1929,7 +1929,7 @@ intel_hdmi_detect(struct drm_connector > > > > > *connector, bool force) > > > > > intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS); > > > > > > > > > > - if (IS_ICELAKE(dev_priv) && > > > > > + if ((IS_ICELAKE(dev_priv) || IS_GEN9_BC(dev_priv)) && > > > > > !intel_digital_port_connected(encoder)) > > > > > goto out; > > > > > > > _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
