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From: Daniel Vetter <daniel.vetter@ffwll.ch>
To: DRI Development <dri-devel@lists.freedesktop.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Subject: [PATCH 23/35] drm: nest modeset locks within fpriv->fbs_lock
Date: Thu, 10 Jan 2013 21:48:04 +0100
Message-ID: <1357850897-27102-24-git-send-email-daniel.vetter@ffwll.ch> (raw)
In-Reply-To: <1357850897-27102-1-git-send-email-daniel.vetter@ffwll.ch>

Atm we still need to unconditionally take the modeset locks in the
rmfb paths. But eventually we only want to take them if there are
other users around as a slow-path. This way sane userspace avoids
blocking on edid reads and other stuff in rmfb if it ensures that the
fb isn't used anywhere by a crtc/plane.

We can do a quick check for such other users once framebuffers are
properly refcounting by locking at the refcount - if it's more than 1,
there are other users left. Again, rmfb racing against other ioctls
isn't a real problem, userspace is allowed to shoot its foot.

This patch just prepares this by moving the modeset locks to nest
within fpriv->fbs_lock. Now the distinction between the fbs_lock and
the device-global fb_lock is clear, since we need to hold the fbs_lock
outside of any modeset_locks in fb_release.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/drm_crtc.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index b6eecd2..b2a845b 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -2282,13 +2282,13 @@ int drm_mode_addfb(struct drm_device *dev,
 		drm_modeset_unlock_all(dev);
 		return PTR_ERR(fb);
 	}
+	drm_modeset_unlock_all(dev);
 
 	mutex_lock(&file_priv->fbs_lock);
 	or->fb_id = fb->base.id;
 	list_add(&fb->filp_head, &file_priv->fbs);
 	DRM_DEBUG_KMS("[FB:%d]\n", fb->base.id);
 	mutex_unlock(&file_priv->fbs_lock);
-	drm_modeset_unlock_all(dev);
 
 	return ret;
 }
@@ -2465,6 +2465,7 @@ int drm_mode_addfb2(struct drm_device *dev,
 		drm_modeset_unlock_all(dev);
 		return PTR_ERR(fb);
 	}
+	drm_modeset_unlock_all(dev);
 
 	mutex_lock(&file_priv->fbs_lock);
 	r->fb_id = fb->base.id;
@@ -2472,7 +2473,6 @@ int drm_mode_addfb2(struct drm_device *dev,
 	DRM_DEBUG_KMS("[FB:%d]\n", fb->base.id);
 	mutex_unlock(&file_priv->fbs_lock);
 
-	drm_modeset_unlock_all(dev);
 
 	return ret;
 }
@@ -2670,7 +2670,6 @@ void drm_fb_release(struct drm_file *priv)
 	struct drm_device *dev = priv->minor->dev;
 	struct drm_framebuffer *fb, *tfb;
 
-	drm_modeset_lock_all(dev);
 	mutex_lock(&priv->fbs_lock);
 	list_for_each_entry_safe(fb, tfb, &priv->fbs, filp_head) {
 
@@ -2682,10 +2681,11 @@ void drm_fb_release(struct drm_file *priv)
 		list_del_init(&fb->filp_head);
 
 		/* This will also drop the fpriv->fbs reference. */
+		drm_modeset_lock_all(dev);
 		drm_framebuffer_remove(fb);
+		drm_modeset_unlock_all(dev);
 	}
 	mutex_unlock(&priv->fbs_lock);
-	drm_modeset_unlock_all(dev);
 }
 
 /**
-- 
1.7.10.4

  parent reply index

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-10 20:47 [PATCH 00/36] kms locking rework Daniel Vetter
2013-01-10 20:47 ` [PATCH 01/35] drm: review locking rules in drm_crtc.c Daniel Vetter
2013-01-10 20:47 ` [PATCH 02/35] drm/doc: integrate drm_crtc.c kerneldoc Daniel Vetter
2013-01-10 20:47 ` [PATCH 03/35] drm/<drivers>: reorder framebuffer init sequence Daniel Vetter
2013-01-11 21:06   ` Rob Clark
2013-01-10 20:47 ` [PATCH 04/35] drm/vmwgfx: " Daniel Vetter
2013-01-10 20:47 ` [PATCH 05/35] drm/gma500: move fbcon restore to lastclose Daniel Vetter
2013-01-10 20:47 ` [PATCH 06/35] drm/nouveau: protect evo_wait/evo_kick sections with a channel mutex Daniel Vetter
2013-01-10 20:47 ` [PATCH 07/35] drm/nouveau: try to protect nbo->pin_refcount Daniel Vetter
2013-01-10 20:47 ` [PATCH 08/35] drm/<drivers>: Unified handling of unimplemented fb->create_handle Daniel Vetter
2013-01-18 15:00   ` Thierry Reding
2013-01-18 18:32     ` Daniel Vetter
2013-01-10 20:47 ` [PATCH 09/35] drm: encapsulate crtc->set_config calls Daniel Vetter
2013-01-10 20:47 ` [PATCH 10/35] drm: add drm_modeset_lock|unlock_all Daniel Vetter
2013-01-10 20:47 ` [PATCH 11/35] drm/i915: use drm_modeset_lock_all Daniel Vetter
2013-01-10 20:47 ` [PATCH 12/35] drm/gma500: " Daniel Vetter
2013-01-10 22:36   ` Alan Cox
2013-01-11 13:25     ` Daniel Vetter
2013-01-10 20:47 ` [PATCH 13/35] drm/ast: " Daniel Vetter
2013-01-10 20:47 ` [PATCH 14/35] drm/shmobile: " Daniel Vetter
2013-01-10 20:47 ` [PATCH 15/35] drm/vmgfx: " Daniel Vetter
2013-01-10 20:47 ` [PATCH 16/35] drm: add per-crtc locks Daniel Vetter
2013-01-10 20:47 ` [PATCH 17/35] drm: only take the crtc lock for ->cursor_set Daniel Vetter
2013-01-10 20:47 ` [PATCH 18/35] drm: only take the crtc lock for ->cursor_move Daniel Vetter
2013-01-10 20:48 ` [PATCH 19/35] drm: revamp locking around fb creation/destruction Daniel Vetter
2013-01-10 20:48 ` [PATCH 20/35] drm: create drm_framebuffer_lookup Daniel Vetter
2013-01-10 20:48 ` [PATCH 21/35] drm: revamp framebuffer cleanup interfaces Daniel Vetter
2013-01-10 20:48 ` [PATCH 22/35] drm: reference framebuffers which are on the idr Daniel Vetter
2013-01-10 20:48 ` Daniel Vetter [this message]
2013-01-10 20:48 ` [PATCH 24/35] drm: push modeset_lock_all into ->fb_create driver callbacks Daniel Vetter
2013-01-10 20:48 ` [PATCH 25/35] drm: don't take modeset locks in getfb ioctl Daniel Vetter
2013-01-10 20:48 ` [PATCH 26/35] drm: fb refcounting for dirtyfb_ioctl Daniel Vetter
2013-01-10 20:48 ` [PATCH 27/35] drm: refcounting for sprite framebuffers Daniel Vetter
2013-01-10 20:48 ` [PATCH 28/35] drm: refcounting for crtc framebuffers Daniel Vetter
2013-01-10 20:48 ` [PATCH 29/35] drm/i915: dump refcount into framebuffer debugfs file Daniel Vetter
2013-01-11 22:20   ` Rob Clark
2013-01-10 20:48 ` [PATCH 30/35] drm/vmwgfx: add proper framebuffer refcounting Daniel Vetter
2013-01-10 20:48 ` [PATCH 31/35] drm: optimize drm_framebuffer_remove Daniel Vetter
2013-01-10 20:48 ` [PATCH 32/35] drm: only grab the crtc lock for pageflips Daniel Vetter
2013-01-10 20:48 ` [PATCH 33/35] drm: don't hold crtc mutexes for connector ->detect callbacks Daniel Vetter
2013-01-10 20:48 ` [PATCH 34/35] drm/doc: updates for new framebuffer lifetime rules Daniel Vetter
2013-01-10 20:48 ` [PATCH 35/35] drm/fb_helper: check whether fbcon is bound Daniel Vetter
2013-01-10 20:48 ` [PATCH 36/36] drm/i915: wake up all pageflip waiters Daniel Vetter
2013-01-10 20:50   ` Daniel Vetter
2013-01-11 23:17 ` [PATCH 00/36] kms locking rework Rob Clark

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