diff mbox series

[4/4] drm/i915/icl: Handle GT interrupts after enabling master

Message ID 20181002140552.1051-4-mika.kuoppala@linux.intel.com (mailing list archive)
State New, archived
Headers show
Series [1/4] drm/i915/gen8: Disable master intr before reading | expand

Commit Message

Mika Kuoppala Oct. 2, 2018, 2:05 p.m. UTC
Don't keep master disabled while we handle the current
interrupts. This should help a little on latency of
generating the next interrupt.

Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
---
 drivers/gpu/drm/i915/i915_irq.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

Comments

Chris Wilson Oct. 2, 2018, 3:21 p.m. UTC | #1
Quoting Mika Kuoppala (2018-10-02 15:05:52)
> Don't keep master disabled while we handle the current
> interrupts. This should help a little on latency of
> generating the next interrupt.
> 
> Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_irq.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 5d1f53723388..9d8d5fb68c84 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3163,9 +3163,6 @@ static irqreturn_t gen11_irq_handler(int irq, void *arg)
>                 return IRQ_NONE;
>         }
>  
> -       /* Find, clear, then process each source of interrupt. */
> -       gen11_gt_irq_handler(i915, master_ctl);
> -
>         /* IRQs are synced during runtime_suspend, we don't require a wakeref */
>         if (master_ctl & GEN11_DISPLAY_IRQ) {
>                 const u32 disp_ctl = raw_reg_read(regs, GEN11_DISPLAY_INT_CTL);
> @@ -3183,6 +3180,7 @@ static irqreturn_t gen11_irq_handler(int irq, void *arg)
>  
>         gen11_master_intr_enable(regs);
>  
> +       gen11_gt_irq_handler(i915, master_ctl);

Are we not still acking GT_INTR_DW at this point?
-Chris
Mika Kuoppala Oct. 11, 2018, 2:19 p.m. UTC | #2
Chris Wilson <chris@chris-wilson.co.uk> writes:

> Quoting Mika Kuoppala (2018-10-02 15:05:52)
>> Don't keep master disabled while we handle the current
>> interrupts. This should help a little on latency of
>> generating the next interrupt.
>> 
>> Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
>> Cc: Chris Wilson <chris@chris-wilson.co.uk>
>> Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
>> ---
>>  drivers/gpu/drm/i915/i915_irq.c | 4 +---
>>  1 file changed, 1 insertion(+), 3 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
>> index 5d1f53723388..9d8d5fb68c84 100644
>> --- a/drivers/gpu/drm/i915/i915_irq.c
>> +++ b/drivers/gpu/drm/i915/i915_irq.c
>> @@ -3163,9 +3163,6 @@ static irqreturn_t gen11_irq_handler(int irq, void *arg)
>>                 return IRQ_NONE;
>>         }
>>  
>> -       /* Find, clear, then process each source of interrupt. */
>> -       gen11_gt_irq_handler(i915, master_ctl);
>> -
>>         /* IRQs are synced during runtime_suspend, we don't require a wakeref */
>>         if (master_ctl & GEN11_DISPLAY_IRQ) {
>>                 const u32 disp_ctl = raw_reg_read(regs, GEN11_DISPLAY_INT_CTL);
>> @@ -3183,6 +3180,7 @@ static irqreturn_t gen11_irq_handler(int irq, void *arg)
>>  
>>         gen11_master_intr_enable(regs);
>>  
>> +       gen11_gt_irq_handler(i915, master_ctl);
>
> Are we not still acking GT_INTR_DW at this point?

We are.
-Mika
Chris Wilson Oct. 11, 2018, 2:56 p.m. UTC | #3
Quoting Mika Kuoppala (2018-10-11 15:19:24)
> Chris Wilson <chris@chris-wilson.co.uk> writes:
> 
> > Quoting Mika Kuoppala (2018-10-02 15:05:52)
> >> Don't keep master disabled while we handle the current
> >> interrupts. This should help a little on latency of
> >> generating the next interrupt.
> >> 
> >> Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
> >> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> >> Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/i915_irq.c | 4 +---
> >>  1 file changed, 1 insertion(+), 3 deletions(-)
> >> 
> >> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> >> index 5d1f53723388..9d8d5fb68c84 100644
> >> --- a/drivers/gpu/drm/i915/i915_irq.c
> >> +++ b/drivers/gpu/drm/i915/i915_irq.c
> >> @@ -3163,9 +3163,6 @@ static irqreturn_t gen11_irq_handler(int irq, void *arg)
> >>                 return IRQ_NONE;
> >>         }
> >>  
> >> -       /* Find, clear, then process each source of interrupt. */
> >> -       gen11_gt_irq_handler(i915, master_ctl);
> >> -
> >>         /* IRQs are synced during runtime_suspend, we don't require a wakeref */
> >>         if (master_ctl & GEN11_DISPLAY_IRQ) {
> >>                 const u32 disp_ctl = raw_reg_read(regs, GEN11_DISPLAY_INT_CTL);
> >> @@ -3183,6 +3180,7 @@ static irqreturn_t gen11_irq_handler(int irq, void *arg)
> >>  
> >>         gen11_master_intr_enable(regs);
> >>  
> >> +       gen11_gt_irq_handler(i915, master_ctl);
> >
> > Are we not still acking GT_INTR_DW at this point?
> 
> We are.

Then we re-enable MASTER before we ack the in the individual GT_IIR, and
by the logic before, that means MASTER still has the GT bits asserted
(as we said they are not cleared until we ack the individual GT_IIR).
Doesn't that mean that the interrupt will be raised again immediately?
-Chris
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 5d1f53723388..9d8d5fb68c84 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -3163,9 +3163,6 @@  static irqreturn_t gen11_irq_handler(int irq, void *arg)
 		return IRQ_NONE;
 	}
 
-	/* Find, clear, then process each source of interrupt. */
-	gen11_gt_irq_handler(i915, master_ctl);
-
 	/* IRQs are synced during runtime_suspend, we don't require a wakeref */
 	if (master_ctl & GEN11_DISPLAY_IRQ) {
 		const u32 disp_ctl = raw_reg_read(regs, GEN11_DISPLAY_INT_CTL);
@@ -3183,6 +3180,7 @@  static irqreturn_t gen11_irq_handler(int irq, void *arg)
 
 	gen11_master_intr_enable(regs);
 
+	gen11_gt_irq_handler(i915, master_ctl);
 	gen11_gu_misc_irq_handler(i915, gu_misc_iir);
 
 	return IRQ_HANDLED;