[Intel-gfx] [PATCH 11/13] drm/i915/bxt: Enable IPC support

[Mahesh Kumar]

Hi,


On Thursday 13 July 2017 04:18 PM, Chris Wilson wrote:
> Quoting Mahesh Kumar (2017-07-13 11:39:02)
>> +void intel_enable_ipc(struct drm_i915_private *dev_priv)
>> +{
>> +       u32 val;
>> +
>> +       val = I915_READ(DISP_ARB_CTL2);
>> +
>> +       if (dev_priv->ipc_enabled)
>> +               val |= DISP_IPC_ENABLE;
>> +       else
>> +               val &= ~DISP_IPC_ENABLE;
>> +
>> +       I915_WRITE(DISP_ARB_CTL2, val);
>> +}
>> +
>> +void intel_init_ipc(struct drm_i915_private *dev_priv)
>> +{
>> +       dev_priv->ipc_enabled = false;
>> +       if (INTEL_GEN(dev_priv) < 9 || IS_SKYLAKE(dev_priv))
>> +               return;
> So dev_priv->ipc_enabled is just a dev_priv->info.has_ipc, its state
> never changes at runtime?
For debug purpose we may want to disable ipc, So no, it's value 
(dev_priv->ipc_enabled) will not be a fixed value.
I have a plan to make a debugfs entry to change the IPC value at runtime.
But having it also in dev_priv->info.has_ipc a good idea, It will make 
condition check easy.
I'll float another patch incorporating this change.

thanks,
-Mahesh
> Using a intel_device_info field then has a few
> useful side-effects including automatic printing in the lists of
> capabilities.
> -Chris