[igt-dev] [PATCH 1/2] lib/ioctl_wrappers: Query if device supports set/get legacy tiling

[Vanshidhar Konda]

On Thu, Nov 14, 2019 at 09:42:24PM -0800, Dixit, Ashutosh wrote:
>On Thu, 14 Nov 2019 21:33:25 -0800, Vanshidhar Konda wrote:
>>
>> Add a method to query if the device supports setting and
>> getting legacy tiling formats for buffer objects.
>>
>> Signed-off-by: Vanshidhar Konda <vanshidhar.r.konda at intel.com>
>> ---
>>  lib/ioctl_wrappers.c | 16 ++++++++++++++++
>>  lib/ioctl_wrappers.h |  1 +
>>  2 files changed, 17 insertions(+)
>>
>> diff --git a/lib/ioctl_wrappers.c b/lib/ioctl_wrappers.c
>> index 628f8b83..837ef2cf 100644
>> --- a/lib/ioctl_wrappers.c
>> +++ b/lib/ioctl_wrappers.c
>> @@ -133,6 +133,22 @@ __gem_get_tiling(int fd, struct drm_i915_gem_get_tiling *arg)
>>	return err;
>>  }
>>
>> +/**
>> + * gem_has_legacy_hw_tiling:
>> + * @fd: open i915 drm file descriptor
>> + *
>> + * Feature check to query if the device supports setting/getting
>> + * legacy tiling formats for buffer objects
>> + *
>> + * Returns: True if tiling is supported
>> + */
>> +bool
>> +gem_has_legacy_hw_tiling(int fd)
>> +{
>> +	struct drm_i915_gem_get_tiling arg = {};
>> +	return (__gem_get_tiling(fd, &arg) != -EOPNOTSUPP);
>
>Probably just
>
>	return !__gem_get_tiling(fd, &arg);

No. Only this specific error means it is not supported by the hardware.
Other errors could mean that I made a mistake with the arguments - I've
not set them to valid values.

Vanshi

>
>That is, no need to check for specific error code?