Quoting Chris Wilson (2017-11-08 16:18:27)
Quoting Ville Syrjala (2017-11-08 13:35:55)
From: Ville Syrjälä ville.syrjala@linux.intel.com
Apparently setting up a bunch of GT registers before we've properly initialized the rest of the GT hardware leads to these setting being lost. So looks like I broke HSW with commit b7048ea12fbb ("drm/i915: Do .init_clock_gating() earlier to avoid it clobbering watermarks") by doing init_clock_gating() too early. This should actually affect other platforms as well, but apparently not to such a great degree.
What I was ultimately after in that commit was to move the ilk_init_lp_watermarks() call earlier. So let's undo the damage and move init_clock_gating() back to where it was, and call ilk_init_lp_watermarks() just before the watermark state readout.
This highlights how fragile and messed up our init order really is. I wonder why we even initialize the display before gem. The opposite order would make much more sense to me...
v2: Keep WaRsPkgCStateDisplayPMReq:hsw early as it really must be done before all planes might get disabled.
Cc: stable@vger.kernel.org Cc: Chris Wilson chris@chris-wilson.co.uk Cc: Mark Janes mark.a.janes@intel.com Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: Oscar Mateo oscar.mateo@intel.com Cc: Mika Kuoppala mika.kuoppala@linux.intel.com Reported-by: Mark Janes mark.a.janes@intel.com Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103549 Fixes: b7048ea12fbb ("drm/i915: Do .init_clock_gating() earlier to avoid it clobbering watermarks") References: https://lists.freedesktop.org/archives/intel-gfx/2017-November/145432.html Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com
CTS remains fixed, Tested-by: Chris Wilson chris@chris-wilson.co.uk
I know of no reason why this should work in this order,
s/should work/should not/work ;)
Reviewed-by: Chris Wilson chris@chris-wilson.co.uk (but I didn't know about the v2 requirement either!) -Chris