diff options
| author | Dave Gordon <david.s.gordon@intel.com> | 2016-09-12 23:19:35 +0300 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2016-09-15 12:55:43 +0300 |
| commit | b20e3cfe4b7dc62869a1f7e25d910a039c9aeb15 (patch) | |
| tree | ce95a917dfdbbab8226514764fd11dea667904d8 /drivers/gpu/drm/i915/intel_guc_loader.c | |
| parent | b0876afdff45a4714e11f18ebbfb81762b417eac (diff) | |
| download | linux-b20e3cfe4b7dc62869a1f7e25d910a039c9aeb15.tar.xz | |
drm/i915: clarify PMINTRMSK/pm_intr_keep usage
No functional changes; just renaming a bit, tweaking a datatype,
prettifying layout, and adding comments, in particular in the
GuC setup code that touches this data.
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1473711577-11454-2-git-send-email-david.s.gordon@intel.com
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_guc_loader.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_guc_loader.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c index 853928f21596..00217481f1fa 100644 --- a/drivers/gpu/drm/i915/intel_guc_loader.c +++ b/drivers/gpu/drm/i915/intel_guc_loader.c @@ -134,13 +134,28 @@ static void direct_interrupts_to_guc(struct drm_i915_private *dev_priv) I915_WRITE(GUC_WD_VECS_IER, ~irqs); /* - * If GuC has routed PM interrupts to itself, don't keep it. - * and keep other interrupts those are unmasked by GuC. - */ + * The REDIRECT_TO_GUC bit of the PMINTRMSK register directs all + * (unmasked) PM interrupts to the GuC. All other bits of this + * register *disable* generation of a specific interrupt. + * + * 'pm_intr_keep' indicates bits that are NOT to be set when + * writing to the PM interrupt mask register, i.e. interrupts + * that must not be disabled. + * + * If the GuC is handling these interrupts, then we must not let + * the PM code disable ANY interrupt that the GuC is expecting. + * So for each ENABLED (0) bit in this register, we must SET the + * bit in pm_intr_keep so that it's left enabled for the GuC. + * + * OTOH the REDIRECT_TO_GUC bit is initially SET in pm_intr_keep + * (so interrupts go to the DISPLAY unit at first); but here we + * need to CLEAR that bit, which will result in the register bit + * being left SET! + */ tmp = I915_READ(GEN6_PMINTRMSK); - if (tmp & GEN8_PMINTR_REDIRECT_TO_NON_DISP) { - dev_priv->rps.pm_intr_keep |= ~(tmp & ~GEN8_PMINTR_REDIRECT_TO_NON_DISP); - dev_priv->rps.pm_intr_keep &= ~GEN8_PMINTR_REDIRECT_TO_NON_DISP; + if (tmp & GEN8_PMINTR_REDIRECT_TO_GUC) { + dev_priv->rps.pm_intr_keep |= ~tmp; + dev_priv->rps.pm_intr_keep &= ~GEN8_PMINTR_REDIRECT_TO_GUC; } } |