On Wed, 20 Apr 2022, "Vivi, Rodrigo" <rodrigo.vivi@xxxxxxxxx> wrote: > On Tue, 2022-04-19 at 22:54 -0700, Dixit, Ashutosh wrote: >> On Fri, 15 Apr 2022 03:21:26 -0700, Rodrigo Vivi wrote: >> > On Thu, Apr 14, 2022 at 03:31:07PM -0700, Dixit, Ashutosh wrote: >> > > On Thu, 14 Apr 2022 06:28:57 -0700, Jani Nikula wrote: >> > > > >> > > > On Wed, 13 Apr 2022, Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx> >> > > > wrote: >> > > > > Each gt contains an independent instance of pcode. Extend >> > > > > pcode functions >> > > > > to interface with pcode on different gt's. Previous (GT0) >> > > > > pcode read/write >> > > > > interfaces are preserved. >> > > > >> > > > The big problem here is that this hard couples display code to >> > > > gt code, >> > > > while we're trying hard to go the opposite direction. It >> > > > doesn't matter >> > > > that the existing interfaces are preserved as wrappers when it >> > > > relies on >> > > > an intel_gt being available (via i915->gt0). >> > >> > I don't believe there is a big problem in here... >> > >> > please note the intel_pcode.h is keeping the abstraction for >> > display >> > >> > #define snb_pcode_write_timeout(i915, mbox, val, fast_timeout_us, >> > slow_timeout_ms) \ >> > intel_gt_pcode_write_timeout(&(i915)->gt0, mbox, val, >> > fast_timeout_us, slow_timeout_ms) >> > >> > #define snb_pcode_write(i915, mbox, val) \ >> > snb_pcode_write_timeout(i915, mbox, val, 500, 0) >> > >> > display only uses these macros that Ashutosh didn't touch. >> > >> > > > >> > > > Note how 'git grep intel_gt -- drivers/gpu/drm/i915/display/' >> > > > matches >> > > > only 1 line. >> > >> > As well with the patches applied: >> > >> > $ git log --oneline -1 >> > 1f58f1195478 (HEAD -> drm-tip) drm/i915/gt: Expose per-gt RPS >> > defaults in sysfs >> > >> > $ git grep intel_gt -- drivers/gpu/drm/i915/display/ >> > drivers/gpu/drm/i915/display/intel_display.c: >> > intel_gt_set_wedged(to_gt(dev_priv)); >> > >> > > >> > > Hi Jani, would you have suggestions about how to do this (handle >> > > pcode on >> > > multiple gt's)? The thinking was this patch would be a >> > > straightforward way >> > > to avoid code duplication. Also: >> > >> > Maybe it is just a matter of renaming the macros used by display >> > in intel_pcode.h to reflect that it should be used by display only? >> >> In v2 I have added a patch ([PATCH 4/9] drm/i915/gt: Convert callers >> to >> user per-gt pcode functions) which correctly calls per-gt pcode >> functions >> where this is required. With this patch only display functions (and >> one >> other caller) are left calling the "global scope" >> snb_pcode_read/write* >> functions. So the legacy snb_pcode_read/write* are now basically >> being used >> only by display. Let's see if Jani is ok with this. Thanks. > > Jani is not happy with this abstraction because it still creates some > dependency and also no with the name intel_gt_pcode_ in the > functions... > > He has some valid points. > > I believe the right way to do this is to keep intel_pcode totally clean > from intel_gt and only receive intel_uncore as the argument. Then, if > needed we create display/intel_display_pcode and/or gt/intel_gt_pcode > with the needed abstractions... but better with none I'd say. I'd prefer it if you only passed uncore, not gt, to the pcode functions. BR, Jani. -- Jani Nikula, Intel Open Source Graphics Center
