Disable master interrupt before reading level indications.
This will close a race where we get a level indication between
reading and disabling, generating an extra interrupt where we
could have avoided one.
Further, as the reading acts also as a post, replace the
write/post on the irq reset with the helper. On enabling side,
posting doesn't serve any purpose so it can also be replaced
with helper.
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@xxxxxxxxx>
Signed-off-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_irq.c | 37 ++++++++++++++++++++++-----------
1 file changed, 25 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index e0310ebd9c8d..5d1f53723388 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -3129,6 +3129,24 @@ gen11_gu_misc_irq_handler(struct drm_i915_private *dev_priv, const u32 iir)
intel_opregion_asle_intr(dev_priv);
}
+static inline u32 gen11_master_intr_disable(void __iomem * const regs)
+{
+ raw_reg_write(regs, GEN11_GFX_MSTR_IRQ, 0);
+
+ /*
+ * Now with master disabled, get a sample of level indications
+ * for this interrupt. Indications will be cleared on related acks.
+ * New indications can and will light up during processing,
+ * and will generate new interrupt after enabling master.
+ */
+ return raw_reg_read(regs, GEN11_GFX_MSTR_IRQ);
+}
+
+static inline void gen11_master_intr_enable(void __iomem * const regs)
+{
+ raw_reg_write(regs, GEN11_GFX_MSTR_IRQ, GEN11_MASTER_IRQ);
+}
+
static irqreturn_t gen11_irq_handler(int irq, void *arg)
{
struct drm_i915_private * const i915 = to_i915(arg);
@@ -3139,13 +3157,11 @@ static irqreturn_t gen11_irq_handler(int irq, void *arg)
if (!intel_irqs_enabled(i915))
return IRQ_NONE;
- master_ctl = raw_reg_read(regs, GEN11_GFX_MSTR_IRQ);
- master_ctl &= ~GEN11_MASTER_IRQ;
- if (!master_ctl)
+ master_ctl = gen11_master_intr_disable(regs);
+ if (!master_ctl) {
+ gen11_master_intr_enable(regs);
return IRQ_NONE;
-
- /* Disable interrupts. */
- raw_reg_write(regs, GEN11_GFX_MSTR_IRQ, 0);
+ }
/* Find, clear, then process each source of interrupt. */
gen11_gt_irq_handler(i915, master_ctl);
@@ -3165,8 +3181,7 @@ static irqreturn_t gen11_irq_handler(int irq, void *arg)
gu_misc_iir = gen11_gu_misc_irq_ack(i915, master_ctl);
- /* Enable interrupts. */
- raw_reg_write(regs, GEN11_GFX_MSTR_IRQ, GEN11_MASTER_IRQ);
+ gen11_master_intr_enable(regs);
gen11_gu_misc_irq_handler(i915, gu_misc_iir);
@@ -3658,8 +3673,7 @@ static void gen11_irq_reset(struct drm_device *dev)
struct drm_i915_private *dev_priv = dev->dev_private;
int pipe;
- I915_WRITE(GEN11_GFX_MSTR_IRQ, 0);
- POSTING_READ(GEN11_GFX_MSTR_IRQ);
+ gen11_master_intr_disable(dev_priv->regs);
gen11_gt_irq_reset(dev_priv);
@@ -4323,8 +4337,7 @@ static int gen11_irq_postinstall(struct drm_device *dev)
I915_WRITE(GEN11_DISPLAY_INT_CTL, GEN11_DISPLAY_IRQ_ENABLE);
- I915_WRITE(GEN11_GFX_MSTR_IRQ, GEN11_MASTER_IRQ);
- POSTING_READ(GEN11_GFX_MSTR_IRQ);
+ gen11_master_intr_enable(dev_priv->regs);
return 0;
}
--
2.17.1
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
