Hi!
On Wed, Jul 29, 2020 at 04:02:06PM +0100, Dave Stevenson wrote:
Hi Maxime
On Wed, 8 Jul 2020 at 18:42, Maxime Ripard maxime@cerno.tech wrote:
The vc4 atomic commit loop has an handrolled loop that is basically identical to for_each_new_crtc_state, let's convert it to that helper.
Signed-off-by: Maxime Ripard maxime@cerno.tech
drivers/gpu/drm/vc4/vc4_kms.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c index 210cc2408087..717673b18132 100644 --- a/drivers/gpu/drm/vc4/vc4_kms.c +++ b/drivers/gpu/drm/vc4/vc4_kms.c @@ -152,14 +152,13 @@ vc4_atomic_complete_commit(struct drm_atomic_state *state) struct drm_device *dev = state->dev; struct vc4_dev *vc4 = to_vc4_dev(dev); struct vc4_hvs *hvs = vc4->hvs;
struct vc4_crtc *vc4_crtc;
struct drm_crtc_state *new_crtc_state;struct drm_crtc *crtc; int i;
for (i = 0; i < dev->mode_config.num_crtc; i++) {if (!state->crtcs[i].ptr || !state->crtcs[i].commit)continue;
for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);for_each_new_crtc_in_state doesn't check !state->crtcs[i].commit as the hand rolled loop did. Sorry, this is my lack of knowledge, but does that actually make any real difference?
I see nothing wrong in calling vc4_hvs_mask_underrun multiple times anyway, so it's most likely going to be harmless anyway, but wanted to query it.
Sorry for not getting back to this earlier.
I don't really know :)
It looks like the commit pointer is always going to be !NULL in our case: https://elixir.bootlin.com/linux/latest/source/include/drm/drm_crtc.h#L385
The only case where it seems to be checked is when using for_each_old_crtc_in_state, and when the commit pointer is being accessed, and we're in neither of those cases.
Since I don't really know though, I guess we can remain on the safe side and keep it for now.
Maxime