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drm/i915/gen8: Disable master intr before reading

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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@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20181015141440.21845-1-mika.kuoppala@linux.intel.com
This commit is contained in:
Mika Kuoppala 2018-10-15 17:14:38 +03:00
parent 04c388d429
commit 4376b9c965
1 changed files with 26 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
drivers/gpu/drm/i915/i915_irq.c
View File

@ -2887,21 +2887,39 @@ gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
return ret; return ret;
} }
static inline u32 gen8_master_intr_disable(void __iomem * const regs)
{
raw_reg_write(regs, GEN8_MASTER_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, GEN8_MASTER_IRQ);
}
static inline void gen8_master_intr_enable(void __iomem * const regs)
{
raw_reg_write(regs, GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL);
}
static irqreturn_t gen8_irq_handler(int irq, void *arg) static irqreturn_t gen8_irq_handler(int irq, void *arg)
{ {
struct drm_i915_private *dev_priv = to_i915(arg); struct drm_i915_private *dev_priv = to_i915(arg);
void __iomem * const regs = dev_priv->regs;
u32 master_ctl; u32 master_ctl;
u32 gt_iir[4]; u32 gt_iir[4];
if (!intel_irqs_enabled(dev_priv)) if (!intel_irqs_enabled(dev_priv))
return IRQ_NONE; return IRQ_NONE;
master_ctl = I915_READ_FW(GEN8_MASTER_IRQ); master_ctl = gen8_master_intr_disable(regs);
master_ctl &= ~GEN8_MASTER_IRQ_CONTROL; if (!master_ctl) {
if (!master_ctl) gen8_master_intr_enable(regs);
return IRQ_NONE; return IRQ_NONE;
}
I915_WRITE_FW(GEN8_MASTER_IRQ, 0);
/* Find, clear, then process each source of interrupt */ /* Find, clear, then process each source of interrupt */
gen8_gt_irq_ack(dev_priv, master_ctl, gt_iir); gen8_gt_irq_ack(dev_priv, master_ctl, gt_iir);
@ -2913,7 +2931,7 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
enable_rpm_wakeref_asserts(dev_priv); enable_rpm_wakeref_asserts(dev_priv);
} }
I915_WRITE_FW(GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL); gen8_master_intr_enable(regs);
gen8_gt_irq_handler(dev_priv, master_ctl, gt_iir); gen8_gt_irq_handler(dev_priv, master_ctl, gt_iir);
@ -3598,8 +3616,7 @@ static void gen8_irq_reset(struct drm_device *dev)
struct drm_i915_private *dev_priv = to_i915(dev); struct drm_i915_private *dev_priv = to_i915(dev);
int pipe; int pipe;
I915_WRITE(GEN8_MASTER_IRQ, 0); gen8_master_intr_disable(dev_priv->regs);
POSTING_READ(GEN8_MASTER_IRQ);
gen8_gt_irq_reset(dev_priv); gen8_gt_irq_reset(dev_priv);
@ -4244,8 +4261,7 @@ static int gen8_irq_postinstall(struct drm_device *dev)
if (HAS_PCH_SPLIT(dev_priv)) if (HAS_PCH_SPLIT(dev_priv))
ibx_irq_postinstall(dev); ibx_irq_postinstall(dev);
I915_WRITE(GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL); gen8_master_intr_enable(dev_priv->regs);
POSTING_READ(GEN8_MASTER_IRQ);
return 0; return 0;
} }