[Intel-gfx] [PATCH 01/19] drm/atomic: Add new iterators over all state

[Maarten Lankhorst]

Op 01-11-16 om 14:09 schreef Ville Syrjälä:
> On Mon, Oct 17, 2016 at 02:37:00PM +0200, Maarten Lankhorst wrote:
>> Add for_each_(old)(new)_(plane,connector,crtc)_in_state iterators to
>> replace the old for_each_xxx_in_state ones. This is useful for >1 flip
>> depth and getting rid of all xxx->state dereferences.
>>
>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
>> ---
>>  drivers/gpu/drm/drm_atomic.c         |  6 +++
>>  drivers/gpu/drm/drm_atomic_helper.c  | 52 +++++++++++++++++++++--
>>  drivers/gpu/drm/i915/intel_display.c | 11 ++---
>>  include/drm/drm_atomic.h             | 81 ++++++++++++++++++++++++++++++++++--
>>  include/drm/drm_atomic_helper.h      |  3 ++
>>  5 files changed, 142 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
>> index 5dd70540219c..120775fcfb70 100644
>> --- a/drivers/gpu/drm/drm_atomic.c
>> +++ b/drivers/gpu/drm/drm_atomic.c
>> @@ -278,6 +278,8 @@ drm_atomic_get_crtc_state(struct drm_atomic_state *state,
>>  		return ERR_PTR(-ENOMEM);
>>  
>>  	state->crtcs[index].state = crtc_state;
>> +	state->crtcs[index].old_state = crtc->state;
>> +	state->crtcs[index].new_state = crtc_state;
>>  	state->crtcs[index].ptr = crtc;
>>  	crtc_state->state = state;
>>  
>> @@ -640,6 +642,8 @@ drm_atomic_get_plane_state(struct drm_atomic_state *state,
>>  
>>  	state->planes[index].state = plane_state;
>>  	state->planes[index].ptr = plane;
>> +	state->planes[index].old_state = plane->state;
>> +	state->planes[index].new_state = plane_state;
>>  	plane_state->state = state;
>>  
>>  	DRM_DEBUG_ATOMIC("Added [PLANE:%d:%s] %p state to %p\n",
>> @@ -931,6 +935,8 @@ drm_atomic_get_connector_state(struct drm_atomic_state *state,
>>  
>>  	drm_connector_reference(connector);
>>  	state->connectors[index].state = connector_state;
>> +	state->connectors[index].old_state = connector->state;
>> +	state->connectors[index].new_state = connector_state;
>>  	state->connectors[index].ptr = connector;
>>  	connector_state->state = state;
>>  
>> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
>> index 07b432f43b98..fcb6e5b55217 100644
>> --- a/drivers/gpu/drm/drm_atomic_helper.c
>> +++ b/drivers/gpu/drm/drm_atomic_helper.c
>> @@ -2495,7 +2495,7 @@ EXPORT_SYMBOL(drm_atomic_helper_disable_all);
>>   *
>>   * See also:
>>   * drm_atomic_helper_duplicate_state(), drm_atomic_helper_disable_all(),
>> - * drm_atomic_helper_resume()
>> + * drm_atomic_helper_resume(), drm_atomic_helper_commit_duplicated_state()
>>   */
>>  struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev)
>>  {
>> @@ -2536,6 +2536,52 @@ unlock:
>>  EXPORT_SYMBOL(drm_atomic_helper_suspend);
>>  
>>  /**
>> + * drm_atomic_helper_commit_duplicated_state - commit duplicated state
>> + * @state: duplicated atomic state to commit
>> + * @ctx: pointer to acquire_ctx to use for commit.
>> + * @nonblock: commit the state non-blocking.
>> + *
>> + * The state returned by drm_atomic_helper_duplicate_state() and
>> + * drm_atomic_helper_suspend() is partially invalid, and needs to
>> + * be fixed up before commit.
> So the old_state pointers are potentially invalid because whatever->state
> may have changed since we duplicated the state?

Yes when you use drm_atomic_helper_duplicate_state, and commit a different state before committing the duplicated state.
This only happens during suspend/resume and gpu reset.

~Maarten