[Intel-gfx] [PATCH 1/5] drm/i915/chv: Remove Wait for a previous gfx force-off

[Deepak S]

On Thursday 26 February 2015 09:12 PM, Deepak S wrote:
>
> On Thursday 26 February 2015 09:13 PM, Ville Syrjälä wrote:
>> On Thu, Feb 26, 2015 at 08:46:54PM +0530, deepak.s at linux.intel.com 
>> wrote:
>>> From: Deepak S <deepak.s at linux.intel.com>
>>>
>>> On CHV, PUNIT team confirmed that 'VLV_GFX_CLK_STATUS_BIT' is not a
>>> sticky bit and it will always be set. So ignore Check for previous
>>> Gfx force off during suspend and allow the force clk as part S0ix
>>> Sequence
>> Do we need the force clock at all since we don't do any gunit register
>> save/restore? I tried to peddle a patch to remove it totally in this bug
>> report, but never got any decent answer back:
>> https://bugs.freedesktop.org/show_bug.cgi?id=87086
>
> hmm. your right we might not need. Let me confirm

Hi Ville,

Based on the spec we still  need to follow the Gfx force clk sequence :(
Can you review the patch to skip wait for previous Gfx force-off?
This patch has gone through lot of S0ix testing.

Thanks
Deepak


>>> Signed-off-by: Deepak S <deepak.s at linux.intel.com>
>>> ---
>>>   drivers/gpu/drm/i915/i915_drv.c | 6 ++++--
>>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_drv.c 
>>> b/drivers/gpu/drm/i915/i915_drv.c
>>> index 4badb23..b88b7b1 100644
>>> --- a/drivers/gpu/drm/i915/i915_drv.c
>>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>>> @@ -1193,11 +1193,13 @@ int vlv_force_gfx_clock(struct 
>>> drm_i915_private *dev_priv, bool force_on)
>>>       int err;
>>>         val = I915_READ(VLV_GTLC_SURVIVABILITY_REG);
>>> -    WARN_ON(!!(val & VLV_GFX_CLK_FORCE_ON_BIT) == force_on);
>>>     #define COND (I915_READ(VLV_GTLC_SURVIVABILITY_REG) & 
>>> VLV_GFX_CLK_STATUS_BIT)
>>>       /* Wait for a previous force-off to settle */
>>> -    if (force_on) {
>>> +    if (force_on && !IS_CHERRYVIEW(dev_priv->dev)) {
>>> +        /* WARN_ON only for the Valleyview */
>>> +        WARN_ON(!!(val & VLV_GFX_CLK_FORCE_ON_BIT) == force_on);
>>> +
>>>           err = wait_for(!COND, 20);
>>>           if (err) {
>>>               DRM_ERROR("timeout waiting for GFX clock force-off 
>>> (%08x)\n",
>>> -- 
>>> 1.9.1
>
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