[Intel-gfx] [PATCH v2 1/2] drm/atomic: move waiting for hw_done to a helper

[Maarten Lankhorst]

Op 14-06-17 om 16:52 schreef Ville Syrjälä:
> On Wed, Jun 14, 2017 at 11:08:41AM +0200, Maarten Lankhorst wrote:
>> Moving the wait to a helper allows callers outside of the core to
>> wait for pending updates to complete.
>>
>> This can be used to prevent races against nonblocking modesets.
>> Only the hw_done call in swap_state is moved to a helper, doing
>> it for the other callers requires too many changes and I think this
>> is the only useful one to export.
>>
>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>> ---
>>  drivers/gpu/drm/drm_atomic_helper.c | 51 +++++++++++++++++++++++++++----------
>>  include/drm/drm_atomic_helper.h     |  1 +
>>  2 files changed, 38 insertions(+), 14 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
>> index 86d3093c6c9b..1b068ce1aea9 100644
>> --- a/drivers/gpu/drm/drm_atomic_helper.c
>> +++ b/drivers/gpu/drm/drm_atomic_helper.c
>> @@ -2067,6 +2067,41 @@ void drm_atomic_helper_cleanup_planes(struct drm_device *dev,
>>  EXPORT_SYMBOL(drm_atomic_helper_cleanup_planes);
>>  
>>  /**
>> + * drm_atomic_helper_wait_for_hw_done - wait for all previous hw updates to complete.
>> + * @crtc: crtc to wait on.
>> + *
>> + * This function waits for all previous hardware updates queued on @crtc
>> + * to complete.
>> + *
>> + * Returns:
>> + * 0 on success, negative error code on failure.
>> + */
>> +int drm_atomic_helper_wait_for_hw_done(struct drm_crtc *crtc)
>> +{
>> +	struct drm_crtc_commit *commit;
>> +	long ret;
>> +
>> +	spin_lock(&crtc->commit_lock);
>> +	commit = list_first_entry_or_null(&crtc->commit_list,
>> +			struct drm_crtc_commit, commit_entry);
>> +	if (commit)
>> +		drm_crtc_commit_get(commit);
>> +	spin_unlock(&crtc->commit_lock);
>> +
>> +	if (!commit)
>> +		return 0;
>> +
>> +	ret = wait_for_completion_timeout(&commit->hw_done, 10 * HZ);
>> +	drm_crtc_commit_put(commit);
>> +
>> +	if (ret == 0)
>> +		return -EBUSY;
> -ETIMEDOUT ?
ETIMEDOUT -> /* Connection timed out */

No I don't think that would match.