[Intel-gfx] [RFC PATCH 2/2] drm/i915: Account for platform without mappable aperture when returning size

[Antonio Argenziano]

On 07/03/19 13:59, Chris Wilson wrote:
> Quoting Antonio Argenziano (2019-03-07 19:11:15)
>> Some devices will not expose a mappable aperture anymore so we need to
>> return an appropriate value in that case.
>>
>> Signed-off-by: Antonio Argenziano <antonio.argenziano at intel.com>
>>
>> Cc: Matthew Auld <matthew.auld at intel.com>
>> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>> ---
>>   drivers/gpu/drm/i915/i915_gem.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
>> index d109f6dbe992..5125a5329100 100644
>> --- a/drivers/gpu/drm/i915/i915_gem.c
>> +++ b/drivers/gpu/drm/i915/i915_gem.c
>> @@ -221,7 +221,8 @@ i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
>>          args->aper_size = ggtt->vm.total;
>>          args->aper_available_size = args->aper_size - pinned;
>>   
>> -       args->mappable_aperture_size = ggtt->mappable_end;
>> +       args->mappable_aperture_size =
>> +                       HAS_MAPPABLE_APERTURE(to_i915(dev)) ? ggtt->mappable_end : (__u64)-ENODEV;
> 
> Looking above, args->aper_size will also be 0 so that'll be a good clue

Is it? ggtt should still be there so that shouldn't be zero.

Antonio

> for ENODEV. So maybe we can get away with the ambiguous 0 here as we can
> use aper_size to differentiate the classes of HW.
> -Chris
>