[PATCH 1/4] drm/i915/display: Disable wakeref asserts around GU_MISC irq handling

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

The GU_MISC/GSE interrupt may be raised even when we're not
holding a runtime PM wakeref. Disable the asserts while
processing GU_MISC irqs. Previously this was covered by
the use of raw_reg_{read,write}() which lack the assert.

Not having an assert is fine since we synchronize irqs
during runtime suspend.

Arguably this stuff shouldn't really be in the display code
since GU_MISC is for Gunit interrupts. But I suppose as long
as we only care about the GSE interrupt bit it doesn't really
matter that the code is misplaced.

Cc: Jani Nikula <jani.nikula at intel.com>
Reported-by: Jason A. Donenfeld <Jason at zx2c4.com>
Closes: https://lore.kernel.org/intel-gfx/aG0tWkfmxWtxl_xc@zx2c4.com/
Fixes: 8d9908e8fe9c ("drm/i915/display: remove small micro-optimizations in irq handling")
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_display_irq.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_irq.c b/drivers/gpu/drm/i915/display/intel_display_irq.c
index fb25ec8adae3..68157f177b6a 100644
--- a/drivers/gpu/drm/i915/display/intel_display_irq.c
+++ b/drivers/gpu/drm/i915/display/intel_display_irq.c
@@ -1506,10 +1506,14 @@ u32 gen11_gu_misc_irq_ack(struct intel_display *display, const u32 master_ctl)
 	if (!(master_ctl & GEN11_GU_MISC_IRQ))
 		return 0;
 
+	intel_display_rpm_assert_block(display);
+
 	iir = intel_de_read(display, GEN11_GU_MISC_IIR);
 	if (likely(iir))
 		intel_de_write(display, GEN11_GU_MISC_IIR, iir);
 
+	intel_display_rpm_assert_unblock(display);
+
 	return iir;
 }
 
-- 
2.49.0