From: David Herrmann Date: Thu, 15 Nov 2012 13:04:37 +0000 (+0000) Subject: drm: fix returning -EINVAL on setmaster if another master is active X-Git-Tag: v3.8-rc1~82^2~191 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=08bec5b4edd13a7cb0bc2fb27c529d794ae67054;p=pandora-kernel.git drm: fix returning -EINVAL on setmaster if another master is active We link every DRM "file_priv" to a "drm_master" structure. Currently, the drmSetMaster() call returns 0 when there is _any_ active master associated with the "drm_master" structure of the calling "file_priv". This means, that after drmSetMaster() we are not guaranteed to be DRM-Master and might not be able to perform mode-setting. A way to reproduce this is by starting weston with the DRM backend from within an X-console (eg., xterm). Because the xserver's "drm_master" is currently active, weston is assigned to the same master but is inactive because its VT is inactive and the xserver is still active. But when "fake-activating" weston, it calls drmSetMaster(). With current behavior this returns "0/success" and weston thinks that it is DRM-Master, even though it is not (as the xserver is still DRM-Master). Expected behavior would be drmSetMaster() to return -EINVAL, because the xserver is still DRM-Master. This patch changes exactly that. The only way this bogus behavior would be useful is for clients to check whether their associated "drm_master" is currently the active DRM-Master. But this logic fails if no DRM-Master is currently active at all. Because then the client itself would become DRM-Master (if it is root) and this makes this whole thing useles. Also note that the second "if-condition": file_priv->minor->master != file_priv->master is always true and can be skipped. Signed-off-by: David Herrmann Signed-off-by: Dave Airlie --- Reading git-diff-tree failed