[Intel-gfx] [PATCH] drm/i915: Disable GEN9LP decoupled mmio

[Jani Nikula]

On Tue, 23 May 2017, Tvrtko Ursulin <tvrtko.ursulin at linux.intel.com> wrote:
> On 23/05/2017 01:18, kai.chen at intel.com wrote:
>> From: Kai Chen <kai.chen at intel.com>
>>
>> This change is used as a backport fix from top of drm-intel ([PATCH]
>> drm/i915: Disable decoupled mmio for GEN9LP) to disable decoupled mmio
>> on GEN9LP for those shipped kernels as a quick fix.
>
> Should we have a more complete commit message for the backportable 
> commit instead? Perhaps copy the one from the full patch, and change it 
> there to refer to this one and explain that it is removing previously 
> disabled code?
>
> For example:
>
> """
> The decoupled mmio feature doesn't work as intended by HW team. Enabling
> it with forcewake will only make debugging efforts more difficult, so
> let's disable it.
> """

I want a two-patch series, with this patch here as 1/2, with the dim
fixes blob and cc: stable from below, and a proper commit message. Patch
2/2 is the other patch with the dead code removal, on top of this one.

BR,
Jani.

>
>
>> V2:
>> - Add signed-off-by
>>
>> Signed-off-by: Kai Chen <kai.chen at intel.com>
>
> Adding the dim fixes blob:
>
> Fixes: 85ee17ebeedd ("drm/i915/bxt: Broxton decoupled MMIO")
> Cc: Zhe Wang <zhe1.wang at intel.com>
> Cc: Praveen Paneri <praveen.paneri at intel.com>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Daniel Vetter <daniel.vetter at intel.com>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: intel-gfx at lists.freedesktop.org

Cc: <stable at vger.kernel.org> # v4.10+

>
> Regards,
>
> Tvrtko
>
>> ---
>>  drivers/gpu/drm/i915/i915_pci.c | 1 -
>>  1 file changed, 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
>> index f80db2c..cf43dc1 100644
>> --- a/drivers/gpu/drm/i915/i915_pci.c
>> +++ b/drivers/gpu/drm/i915/i915_pci.c
>> @@ -385,7 +385,6 @@ static const struct intel_device_info intel_skylake_gt3_info = {
>>  	.has_gmbus_irq = 1, \
>>  	.has_logical_ring_contexts = 1, \
>>  	.has_guc = 1, \
>> -	.has_decoupled_mmio = 1, \
>>  	.has_aliasing_ppgtt = 1, \
>>  	.has_full_ppgtt = 1, \
>>  	.has_full_48bit_ppgtt = 1, \
>>

-- 
Jani Nikula, Intel Open Source Technology Center