Re: [PATCH 1/3] drm/nouveau: Use drm_vblank_on/off consistently

On 05/27/2015 11:04 AM, Daniel Vetter wrote:

In

commit 9cba5efab5a8145ae6c52ea273553f069c294482 Author: Mario Kleiner mario.kleiner.de@gmail.com Date: Tue Jul 29 02:36:44 2014 +0200

 drm/nouveau: Dis/Enable vblank irqs during suspend/resume

drm_vblank_on/off calls where added around suspend/resume to make sure vblank stay doesn't go boom over that transition. But nouveau already used drm_vblank_pre/post_modeset over modesets. Instead use drm_vblank_on/off everyhwere. The slight change here is that after _off drm_vblank_get will refuse to work right away, but nouveau doesn't seem to depend upon that anywhere outside of the pageflip paths.

The longer-term plan here is to switch all kms drivers to drm_vblank_on/off so that common code like pending event cleanup can be done there, while drm_vblank_pre/post_modeset will be purely drm internal for the old UMS ioctl.

Note that the drm_vblank_off still seems required in the suspend path since nouveau doesn't explicitly disable crtcs. But on the resume side drm_helper_resume_force_mode should end up calling drm_vblank_on through the nouveau crtc hooks already. Hence remove the call in the resume code.

Cc: Mario Kleiner mario.kleiner.de@gmail.com Cc: Ben Skeggs bskeggs@redhat.com Signed-off-by: Daniel Vetter daniel.vetter@intel.com

---

drivers/gpu/drm/nouveau/dispnv04/crtc.c | 4 ++-- drivers/gpu/drm/nouveau/nouveau_display.c | 4 ---- 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/dispnv04/crtc.c b/drivers/gpu/drm/nouveau/dispnv04/crtc.c index 3d96b49fe662..dab24066fa21 100644 --- a/drivers/gpu/drm/nouveau/dispnv04/crtc.c +++ b/drivers/gpu/drm/nouveau/dispnv04/crtc.c @@ -708,7 +708,7 @@ static void nv_crtc_prepare(struct drm_crtc *crtc) if (nv_two_heads(dev)) NVSetOwner(dev, nv_crtc->index);

• drm_vblank_pre_modeset(dev, nv_crtc->index);

• drm_vblank_off(dev, nv_crtc->index); funcs->dpms(crtc, DRM_MODE_DPMS_OFF);

  NVBlankScreen(dev, nv_crtc->index, true);

@@ -740,7 +740,7 @@ static void nv_crtc_commit(struct drm_crtc *crtc) #endif

funcs->dpms(crtc, DRM_MODE_DPMS_ON);

• drm_vblank_post_modeset(dev, nv_crtc->index);

• drm_vblank_on(dev, nv_crtc->index); }

The above hunk is probably correct, but i couldn't test it without sufficiently old pre-nv 50 hardware.

static void nv_crtc_destroy(struct drm_crtc *crtc) diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c index 8670d90cdc11..d824023f9fc6 100644 --- a/drivers/gpu/drm/nouveau/nouveau_display.c +++ b/drivers/gpu/drm/nouveau/nouveau_display.c @@ -620,10 +620,6 @@ nouveau_display_resume(struct drm_device *dev, bool runtime) nv_crtc->lut.depth = 0; }

• /* Make sure that drm and hw vblank irqs get resumed if needed. */
• for (head = 0; head < dev->mode_config.num_crtc; head++)

• drm_vblank_on(dev, head);
  

• /* This should ensure we don't hit a locking problem when someone
  • wakes us up via a connector. We should never go into suspend
  • while the display is on anyways.

Tested this one and this hunk breaks suspend/resume. After a suspend/resume cycle, all OpenGL apps and composited desktop are dead, as the core can't get any vblank irq's enabled anymore.

So the drm_vblank_on() is still needed here.

thanks, -mario