Re: [PATCH v2] drm/i915: Fix to Enable GT/PM Interrupts for cherryview.

[Deepak S <deepak.s@intel.com>]

On Thursday 28 August 2014 11:00 AM, Daniel Vetter wrote:
> On Fri, Aug 29, 2014 at 08:45:21AM +0530, Deepak S wrote:
>> On Tuesday 26 August 2014 07:24 PM, Daniel Vetter wrote:
>>> On Fri, Aug 22, 2014 at 08:32:40AM +0530, deepak.s@linux.intel.com wrote:
>>>> From: Deepak S <deepak.s@linux.intel.com>
>>>>
>>>> Programing GT IER interrupts was fumbled while enabling Interrupts for
>>>> gen8
>>>>
>>>> This is a regression from
>>>>      commit abd58f0175915bed644aa67c8f69dc571b8280e0
>>>>      Author: Ben Widawsky <benjamin.widawsky@intel.com>
>>>>      Date:   Sat Nov 2 21:07:09 2013 -0700
>>>>
>>>> 	drm/i915/bdw: Implement interrupt changes
>>> _Really_ unlikely that this is a regression from this commit, since that
>>> introduced all the gen8 interrupt handling in the first place. I think
>>> this is because of the reworked interrupt handling over gpu resets, where
>>> we want to keep rps interrupts enabled. But I'm not terribly sure.
>>>
>>> I think a more convincing story is that this is an oversight from
>>>
>>> commit a6706b45a57a23a613b34793e1414991b60a09c1
>>> Author: Deepak S <deepak.s@linux.intel.com>
>>> Date:   Sat Mar 15 20:23:22 2014 +0530
>>>
>>>      drm/i915: Track the enabled PM interrupts in dev_priv
>>>
>>> or more precisely (since chv wasn't public back then iirc) we forgot to
>>> add the corresponding patch to -internal.
>>>
>>> In any case please clarify the commit message and please also add a few
>>> words about why exactly we need this - I had to dig through git history to
>>> figure this all out.
>>>
>>> I've applied the patch already, so you can just reply with the revised
>>> commit message that I should put in.
>>>
>>> Thanks, Daniel
>> Daniel, This patch is not just for chv right. it affects the gen8(BDW).
>> Your right we might have missed in (drm/i915: Track the enabled PM interrupts in dev_priv).
>> In -internal, for chv, We used to program the IER in enable_interrupts routing so it was already taken care.
>> After the interrupt re-work, we are supposed to add IER in post_irq handler which we missed it.
>>
>> New commit msg:  Is this fine? Do i need to resubmit the patch?
> Yeah fine and thanks for confirming. I've adjusted the commit message.
> -Daniel

Thanks Daniel.

>> ------------------------------------------------------------------
>>
>> Programing GT IER interrupts was fumbled while enabling Interrupts for
>> gen8
>>
>> We forgot to program PM IER interrupt in gen8_gt_irq_postinstall based on the new  re-worked interrupt
>> routines.
>>
>>>> v2: Kill the loop and init GT interrupts (Ville)
>>>>
>>>> Signed-off-by: Deepak S <deepak.s@linux.intel.com>
>>>> ---
>>>>   drivers/gpu/drm/i915/i915_irq.c | 9 ++++-----
>>>>   1 file changed, 4 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
>>>> index d5445e7..c33cf89 100644
>>>> --- a/drivers/gpu/drm/i915/i915_irq.c
>>>> +++ b/drivers/gpu/drm/i915/i915_irq.c
>>>> @@ -3799,8 +3799,6 @@ static int valleyview_irq_postinstall(struct drm_device *dev)
>>>>   static void gen8_gt_irq_postinstall(struct drm_i915_private *dev_priv)
>>>>   {
>>>> -	int i;
>>>> -
>>>>   	/* These are interrupts we'll toggle with the ring mask register */
>>>>   	uint32_t gt_interrupts[] = {
>>>>   		GT_RENDER_USER_INTERRUPT << GEN8_RCS_IRQ_SHIFT |
>>>> @@ -3817,10 +3815,11 @@ static void gen8_gt_irq_postinstall(struct drm_i915_private *dev_priv)
>>>>   			GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VECS_IRQ_SHIFT
>>>>   		};
>>>> -	for (i = 0; i < ARRAY_SIZE(gt_interrupts); i++)
>>>> -		GEN8_IRQ_INIT_NDX(GT, i, ~gt_interrupts[i], gt_interrupts[i]);
>>>> -
>>>>   	dev_priv->pm_irq_mask = 0xffffffff;
>>>> +	GEN8_IRQ_INIT_NDX(GT, 0, ~gt_interrupts[0], gt_interrupts[0]);
>>>> +	GEN8_IRQ_INIT_NDX(GT, 1, ~gt_interrupts[1], gt_interrupts[1]);
>>>> +	GEN8_IRQ_INIT_NDX(GT, 2, dev_priv->pm_irq_mask, dev_priv->pm_rps_events);
>>>> +	GEN8_IRQ_INIT_NDX(GT, 3, ~gt_interrupts[3], gt_interrupts[3]);
>>>>   }
>>>>   static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)
>>>> -- 
>>>> 1.9.1
>>>>
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