On Thu, Oct 10, 2019 at 5:13 PM Sean Paul sean@poorly.run wrote:
From: Sean Paul seanpaul@chromium.org
This reverts commit 1dfdb0e107dbe6ebff3f6bbbe4aad0b5aa87bba4.
As Daniel mentions in his email [1], non-blocking commits don't hold the modeset locks, so we can safely access state as long as these functions are in the commit path. I'm not entirely sure if these have always been isolated to the commit path, but they seem to be now.
[1]- https://lists.freedesktop.org/archives/dri-devel/2019-October/239441.html
Fixes: 1dfdb0e107db ("drm/msm: dpu: Add modeset lock checks where applicable") Cc: Jeykumar Sankaran jsanka@codeaurora.org Cc: Rob Clark robdclark@chromium.org Suggested-by: Daniel Vetter daniel@ffwll.ch Signed-off-by: Sean Paul seanpaul@chromium.org
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 2 -- drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 1 - 2 files changed, 3 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c index db6c9ccf3be26..c645dd201368b 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c @@ -282,8 +282,6 @@ enum dpu_intf_mode dpu_crtc_get_intf_mode(struct drm_crtc *crtc) return INTF_MODE_NONE; }
WARN_ON(!drm_modeset_is_locked(&crtc->mutex));
This one is worse ... it's used in two places: - debugfs, where you actually want to make sure you're holding this lock - atomic_check, where this is broken since you're supposed to look at the free-standing states only, except if you really know what you're doing. Given that there's no comment here, I suspect that's not the case. Note that for atomic_check you're guaranteed to hold the modeset lock.
I'd put a FIXME here, but leave the WARN_ON until this is fixed properly.
/* TODO: Returns the first INTF_MODE, could there be multiple values? */ drm_for_each_encoder_mask(encoder, crtc->dev, crtc->state->encoder_mask) return dpu_encoder_get_intf_mode(encoder);diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c index e393a423d7d7a..0e68e20d19c87 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c @@ -305,7 +305,6 @@ void dpu_kms_encoder_enable(struct drm_encoder *encoder) if (funcs && funcs->commit) funcs->commit(encoder);
WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch
but only for this hunk here. -Daniel
drm_for_each_crtc(crtc, dev) { if (!(crtc->state->encoder_mask & drm_encoder_mask(encoder))) continue;-- Sean Paul, Software Engineer, Google / Chromium OS