[Intel-gfx] [PATCH v13 19/21] drm/i915/guc: Fix enable/disable of GuC GGTT invalidate functions

[Michal Wajdeczko]

On Wed, 11 Oct 2017 19:44:31 +0200, Sagar Arun Kamble  
<sagar.a.kamble at intel.com> wrote:

>
>
> On 10/11/2017 11:05 PM, Michal Wajdeczko wrote:
>> On Wed, 11 Oct 2017 10:54:14 +0200, Sagar Arun Kamble  
>> <sagar.a.kamble at intel.com> wrote:
>>
>>> i915_ggtt_enable_guc has to happen first during i915_gem_resume
>>> if GuC loading is enabled before GTT restore. In case GuC is not
>>> loaded this enabling happening during intel_uc_init_hw need to
>>> skipped. (avoid the GEM_BUG_ON)
>>> i915_ggtt_disable_guc at the end of reset/suspend/unload is needed
>>> post GGTT suspend operations. Calling it during uc_sanitize covers
>>> all scenarios. Hence, it is removed from intel_uc_fini_hw. Also these
>>> needto be protected by struct_mutex. Hence struct_mutex locking is
>>> added in i915_gem_sanitize while sanitizing uC. struct_mutex is already
>>> held during i915_gem_reset_prepare.
>>>
>>> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
>>> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
>>> Cc: Michał Winiarski <michal.winiarski at intel.com>
>>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>>> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
>>> ---
>>>  drivers/gpu/drm/i915/i915_gem.c |  4 ++++
>>>  drivers/gpu/drm/i915/intel_uc.c | 16 +++++++++++-----
>>>  2 files changed, 15 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_gem.c  
>>> b/drivers/gpu/drm/i915/i915_gem.c
>>> index a4bbf6c..77a0746 100644
>>> --- a/drivers/gpu/drm/i915/i915_gem.c
>>> +++ b/drivers/gpu/drm/i915/i915_gem.c
>>> @@ -4759,6 +4759,10 @@ void i915_gem_resume(struct drm_i915_private  
>>> *dev_priv)
>>>      WARN_ON(dev_priv->gt.awake);
>>>     mutex_lock(&dev->struct_mutex);
>>> +    /* We need to notify the guc whenever we change the GGTT */
>>> +    if (i915_modparams.enable_guc_loading)
>>> +        i915_ggtt_enable_guc(dev_priv);
>>> +
>>>      i915_gem_restore_gtt_mappings(dev_priv);
>>>      i915_gem_restore_fences(dev_priv);
>>> diff --git a/drivers/gpu/drm/i915/intel_uc.c  
>>> b/drivers/gpu/drm/i915/intel_uc.c
>>> index 9010ab5..0b799fe 100644
>>> --- a/drivers/gpu/drm/i915/intel_uc.c
>>> +++ b/drivers/gpu/drm/i915/intel_uc.c
>>> @@ -184,8 +184,14 @@ int intel_uc_init_hw(struct drm_i915_private  
>>> *dev_priv)
>>>      guc_disable_communication(guc);
>>>      gen9_reset_guc_interrupts(dev_priv);
>>> -    /* We need to notify the guc whenever we change the GGTT */
>>> -    i915_ggtt_enable_guc(dev_priv);
>>> +    /*
>>> +     * We need to notify the guc whenever we change the GGTT.
>>> +     * During resume from sleep we would have already updated the
>>> +     * GGTT invalidate function for GuC during i915_gem_resume so
>>> +     * we need to skip here. Will enable here on driver load/reset.
>>> +     */
>>> +    if (!guc->suspended)
>>> +        i915_ggtt_enable_guc(dev_priv);
>>>     if (i915_modparams.enable_guc_submission) {
>>>          /*
>>> @@ -309,9 +315,6 @@ void intel_uc_cleanup(struct drm_i915_private  
>>> *dev_priv)
>>>      guc_free_load_err_log(guc);
>>>     i915_guc_submission_cleanup(dev_priv);
>>> -
>>> -    if (i915_modparams.enable_guc_loading)
>>> -        i915_ggtt_disable_guc(dev_priv);
>>>  }
>>> /**
>>> @@ -452,6 +455,9 @@ void intel_uc_sanitize(struct drm_i915_private  
>>> *dev_priv)
>>>      struct intel_uc_fw *huc_fw = &dev_priv->huc.fw;
>>>     if (i915_modparams.enable_guc_loading) {
>>> +        if (guc_fw->load_status == INTEL_UC_FIRMWARE_SUCCESS)
>>
>> Hmm, isn't that check redundant ?
> uc_sanitize can happen without firmware loaded too in which case we

If uc_sanitize can be loaded without firmware loaded, then I assume
i915_modparams.enable_guc_loading will be cleared too, right ?

I'm just wondering if we need to check both modparam and fw status.

> don't want to ggtt_disable_guc.
> if we want to ggtt_disable_guc then we should remove the GEM_BUG_ON in  
> it.

Hmm, this is the way how we run CI tests ;)

>>
>>> + i915_ggtt_disable_guc(dev_priv);
>>> +
>>>          guc_fw->load_status = INTEL_UC_FIRMWARE_NONE;
>>>          huc_fw->load_status = INTEL_UC_FIRMWARE_NONE;
>>>      }
>>
>> Btw, what should we do with "suspended" flag during sanitize ?
> suspended flag is set to true on suspend and false on resume.
> sanitize is done post suspend and before resume so we should not touch  
> it.
> initializing it to false during guc_init_early should take care of  
> reload (during unload we are suspending gem but we wont resume)