341a15bb91
An oddity occurs on Sandybridge, Ivybridge and Haswell (and presumably Valleyview) in that for the period following the GPU restart after a reset, there are no GT interrupts received. From Ville's notes, bit 0 in the HWSTAM corresponds to the render interrupt, and if we unmask it we do see immediate resumption of GT interrupt delivery (via the master irq handler) after the reset. v2: Limit the w/a to the render interrupt from rcs Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107500 Fixes:c549808946("drm/i915: Mask everything in ring HWSTAM on gen6+ in ringbuffer mode") References:d420a50c21("drm/i915: Clean up the HWSTAM mess") Testcase: igt/gem_eio/reset-stress Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180808105101.913-2-chris@chris-wilson.co.uk (cherry picked from commita4a717010f) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>