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authorDaniel Vetter <daniel.vetter@ffwll.ch>2016-06-21 11:54:12 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2016-06-21 22:43:24 +0300
commit95c081c17f284de50eaca60d4d55643a64d39019 (patch)
treec67aa3d3c9008fc1b91d26b58fc9d57f1f820aab /drivers/gpu/drm/drm_lock.c
parent84601dbdea36634a300c24f93b149a251fc64fed (diff)
downloadlinux-95c081c17f284de50eaca60d4d55643a64d39019.tar.xz
drm: Move master pointer from drm_minor to drm_device
There can only be one current master, and it's for the overall device. Render/control minors don't support master-based auth at all. This simplifies the master logic a lot, at least in my eyes: All these additional pointer chases are just confusing. While doing the conversion I spotted some locking fail: - drm_lock/drm_auth check dev->master without holding the master_mutex. This is fallout from commit c996fd0b956450563454e7ccc97a82ca31f9d043 Author: Thomas Hellstrom <thellstrom@vmware.com> Date: Tue Feb 25 19:57:44 2014 +0100 drm: Protect the master management with a drm_device::master_mutex v3 but I honestly don't care one bit about those old legacy drivers using this. - debugfs name info should just grab master_mutex. - And the fbdev helper looked at it to figure out whether someone is using KMS. We just need a consistent value, so READ_ONCE. Aside: We should probably check if anyone has opened a control node too, but I guess current userspace doesn't really do that yet. v2: Balance locking, reported by Julia. v3: Rebase on top of Chris' oops fixes. Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2) Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> (v2) Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1466499262-18717-1-git-send-email-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers/gpu/drm/drm_lock.c')
-rw-r--r--drivers/gpu/drm/drm_lock.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_lock.c b/drivers/gpu/drm/drm_lock.c
index 0fb8f9e73486..ae0a4d39deec 100644
--- a/drivers/gpu/drm/drm_lock.c
+++ b/drivers/gpu/drm/drm_lock.c
@@ -334,7 +334,7 @@ void drm_legacy_lock_release(struct drm_device *dev, struct file *filp)
struct drm_file *file_priv = filp->private_data;
/* if the master has gone away we can't do anything with the lock */
- if (!file_priv->minor->master)
+ if (!dev->master)
return;
if (drm_legacy_i_have_hw_lock(dev, file_priv)) {