Intel-GFX Archive on lore.kernel.org
 help / color / Atom feed
From: Jesse Barnes <jbarnes@virtuousgeek.org>
To: intel-gfx@lists.freedesktop.org
Subject: [PATCH] drm/i915: don't set unpin_work if vblank_get fails
Date: Mon, 22 Aug 2011 11:05:31 -0700
Message-ID: <20110822110531.57d85c32@jbarnes-desktop> (raw)

This fixes a race where we may try to finish a page flip and decrement
the refcount even if our vblank_get failed and we ended up with a
spurious flip pending interrupt.

Fixes https://bugs.freedesktop.org/show_bug.cgi?id=34211.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 2319f62..0910537 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6896,6 +6896,10 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 	work->old_fb_obj = intel_fb->obj;
 	INIT_WORK(&work->work, intel_unpin_work_fn);
 
+	ret = drm_vblank_get(dev, intel_crtc->pipe);
+	if (ret)
+		goto free_work;
+
 	/* We borrow the event spin lock for protecting unpin_work */
 	spin_lock_irqsave(&dev->event_lock, flags);
 	if (intel_crtc->unpin_work) {
@@ -6906,6 +6910,11 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 		return -EBUSY;
 	}
 	intel_crtc->unpin_work = work;
+	/*
+	 * Past this point, if we fail we'll let the flip completion code
+	 * clean up the vblank refcount and pin work.  It'll be a spurious
+	 * completion, but we handle that case.
+	 */
 	spin_unlock_irqrestore(&dev->event_lock, flags);
 
 	intel_fb = to_intel_framebuffer(fb);
@@ -6919,10 +6928,6 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 
 	crtc->fb = fb;
 
-	ret = drm_vblank_get(dev, intel_crtc->pipe);
-	if (ret)
-		goto cleanup_objs;
-
 	work->pending_flip_obj = obj;
 
 	work->enable_stall_check = true;
@@ -6945,7 +6950,6 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc,
 
 cleanup_pending:
 	atomic_sub(1 << intel_crtc->plane, &work->old_fb_obj->pending_flip);
-cleanup_objs:
 	drm_gem_object_unreference(&work->old_fb_obj->base);
 	drm_gem_object_unreference(&obj->base);
 	mutex_unlock(&dev->struct_mutex);
@@ -6953,7 +6957,7 @@ cleanup_objs:
 	spin_lock_irqsave(&dev->event_lock, flags);
 	intel_crtc->unpin_work = NULL;
 	spin_unlock_irqrestore(&dev->event_lock, flags);
-
+free_work:
 	kfree(work);
 
 	return ret;

             reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-22 18:05 Jesse Barnes [this message]
2011-08-22 18:45 ` Keith Packard
2011-08-29 16:44 ` Jesse Barnes
2011-08-29 16:45   ` Jesse Barnes
2011-09-20  4:04     ` Keith Packard
2011-11-11 20:36       ` Jesse Barnes

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20110822110531.57d85c32@jbarnes-desktop \
    --to=jbarnes@virtuousgeek.org \
    --cc=intel-gfx@lists.freedesktop.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Intel-GFX Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/intel-gfx/0 intel-gfx/git/0.git
	git clone --mirror https://lore.kernel.org/intel-gfx/1 intel-gfx/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 intel-gfx intel-gfx/ https://lore.kernel.org/intel-gfx \
		intel-gfx@lists.freedesktop.org
	public-inbox-index intel-gfx

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.freedesktop.lists.intel-gfx


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git