On Thu, Jul 09, 2015 at 06:22:01PM +0530, Sivakumar Thulasimani wrote: > > > On 7/8/2015 8:50 PM, Daniel Vetter wrote: > >On Wed, Jul 08, 2015 at 06:54:06PM +0530, Sivakumar Thulasimani wrote: > >> > >>On 7/7/2015 5:01 PM, Daniel Vetter wrote: > >>>On Tue, Jul 07, 2015 at 04:10:49PM +0530, Sivakumar Thulasimani wrote: > >>>>From: "Thulasimani,Sivakumar" <sivakumar.thulasimani@xxxxxxxxx> > >>>> > >>>>Update the hotplug documentation to explain that hotplug storm > >>>>is not expected for Display port panels and hence is not handled > >>>>in current code. > >>>> > >>>>Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani@xxxxxxxxx> > >>>>--- > >>>> drivers/gpu/drm/i915/intel_hotplug.c | 4 ++++ > >>>> 1 file changed, 4 insertions(+) > >>>> > >>>>diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c > >>>>index bac91a1..7dc5e6a 100644 > >>>>--- a/drivers/gpu/drm/i915/intel_hotplug.c > >>>>+++ b/drivers/gpu/drm/i915/intel_hotplug.c > >>>>@@ -66,6 +66,10 @@ > >>>> * while before being re-enabled. The intention is to mitigate issues raising > >>>> * from broken hardware triggering massive amounts of interrupts and grinding > >>>> * the system to a halt. > >>>>+ * > >>>>+ * Hotplug interrupt storm is not expected on Display port panel, hence the > >>>>+ * current code only handles disabling and later enabling of HPD interrupts > >>>>+ * for HDMI panels through the storm handling set of functions. > >>>This isn't accurate, we handle storms on everything _but_ DP (tv, vga, > >>>sdvo, ...). I'd go with > >>> > >>> * Hotplug interrupt storm is not expected on Display port panel, hence the > >>> * current code doesn't handle irq reenabling when a DP sink is connected > >>> * and the hpd is handled by the DP callbacks. But on DP+ ports > >>> * storms are still handled correctly in all other cases (e.g. due to HDMI > >>> * sinks). > >>> > >>>Could still be improved I think. > >>> > >>>-Daniel > >>> > >>Sorry i don't get the "DP+" reference here. By DP+, do you mean dongles ? > >>passive dongles will report them selves as HDMI to respective detect > >>routines > >>active dongles will be still treated as DP hence not handling HPD will apply > >>to any > >>display connected through active dongle as well. > >DP+ is DP with support for HDMI with level shifter cables (i.e. all the > >ports on intel chips). I just wanted to make it clear that storm handling > >doesn't work if we have a confirmed DP sink on the port, but will work in > >any other cases (nothing or HDMI sink or DVI or whatever connected). Like > >I said some room for improvement ;-) > >-Daniel > how about the following ? > > * current implementation expects that hotplug interrupt storm will not be s/current/Current/ > * seen when display port sink is connected, hence on platforms whose DP > * callback is handled by i915_digport_work_func reenabling of hpd is not > * performed ( it was never expected to be disabled in the first place ;) ) > * this is specific to DP sinks handled by this routine and any other display > * such as HDMI or DVI enabled on the same port will have proper logic since > * it will use i915_hotplug_work_func where this logic is handled. lgtm. -Daniel > > please provide any corrections or new comment to be used, i'll upload a new > patch with > the final approved text block. > > -- > regards, > Sivakumar > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx