> -----Original Message----- > From: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> > Sent: Wednesday, April 24, 2024 3:19 PM > To: Kandpal, Suraj <suraj.kandpal@xxxxxxxxx>; intel-gfx@xxxxxxxxxxxxxxxxxxxxx > Cc: Murthy, Arun R <arun.r.murthy@xxxxxxxxx>; Kandpal, Suraj > <suraj.kandpal@xxxxxxxxx> > Subject: Re: [RFC 0/3] Enable darkscreen detection > > On Wed, 24 Apr 2024, Suraj Kandpal <suraj.kandpal@xxxxxxxxx> wrote: > > Fifo underrun can lead to flicker, screen corruption and blank screen > > in case of pipe hang. > > This patch series aims to enable dark screen detection whenever FIFO > > underruns are hit and in case we face a darkscreen at this point > > instead of disabling irq and fbc we want to try reset the pipe on > > which the underrun has occured and keep a track on the number of times > > underrun occurs post reset and if this persists more than 5 times we > > go ahead and reset the whole display. If this still persists we then > > fallback to disabling irq and the fb. > > To summarize we are using the dark screen detction feature to detect > > the pipe hung scenario of FIFO underrun. After detection as corrective > > measurements following is done. > > 1)pipe reset > > 2)display reset > > Comments on this design and ideas on how else this can be implemented > > or diffrent scenarios dark screen detection can be used are also > > welcome. > > I don't know what the above has to do with the patches posted. Please don't > send this raw patches even as RFC. If you only want to discuss, let's discuss, > but in this case the patches were a distraction, sorry. > > One of the big opens is that AFAICT this still detects desired black screen as > dark screen, and flags it as a problem. Now, the patches do only log something > to dmesg, so it's neither here or there, but if you want to do something more > clever, this is a consideration. > Hi Jani, The patches posted were a little clean up of the work we already have and want to move forward from here. This was posted to initiate a discussion if using this dark screen detection can we reset a pipe or display based on what was written on the cover letter .So yes we do want to replace the simple print and do a pipe reset whenever darkscreen is detected during FIFO underrun. Wanted to have a consent if that would be okay before going ahead and putting efforts on that. Regards, Suraj Kandpal > BR, > Jani. > > > > > > Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx> > > > > Suraj Kandpal (3): > > drm/i915: Add Dark screen detection registers > > drm/i915/darkscreen: Enable darkscreen detection > > drm/i915: Schedule darkscreen detection work > > > > drivers/gpu/drm/i915/Makefile | 1 + > > .../gpu/drm/i915/display/intel_darkscreen.c | 139 ++++++++++++++++++ > > .../gpu/drm/i915/display/intel_darkscreen.h | 25 ++++ > > .../drm/i915/display/intel_display_types.h | 3 + > > .../drm/i915/display/intel_fifo_underrun.c | 2 + > > drivers/gpu/drm/i915/i915_reg.h | 8 + > > drivers/gpu/drm/xe/Makefile | 1 + > > 7 files changed, 179 insertions(+) > > create mode 100644 drivers/gpu/drm/i915/display/intel_darkscreen.c > > create mode 100644 drivers/gpu/drm/i915/display/intel_darkscreen.h > > -- > Jani Nikula, Intel
