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

Deepak S
2015-03-11T14:53:48Z

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@linux.intel.com
>> wrote:
>>> From: Deepak S <deepak.s@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@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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