kernel/drivers/gpu/drm/drm_sysfs.c, branch linux-4.1.y

drm: Fix locking for sysfs dpms file

2015-10-27T00:51:53Z

commit 621bd0f6982badd6483acb191eb7b6226a578328 upstream. With atomic drivers we need to make sure that (at least in general) property reads hold the right locks. But the legacy dpms property is special and can be read locklessly. Since userspace loves to just randomly look at that all the time (like with "status") do that. To make it clear that we play tricks use the READ_ONCE compiler barrier (and also for paranoia). Note that there's not really anything bad going on since even with the new atomic paths we eventually end up not chasing any pointers (and hence possibly freed memory and other fun stuff). The locking WARNING has been added in commit 88a48e297b3a3bac6022c03babfb038f1a886cea Author: Rob Clark Date: Thu Dec 18 16:01:50 2014 -0500 drm: add atomic properties but since drivers are converting not everyone will have seen this from the start. Jens reported this and submitted a patch to just grab the mode_config.connection_mutex, but we can do a bit better. v2: Remove unused variables I failed to git add for real. Reference: http://mid.gmane.org/20150928194822.GA3930@kernel.dk Reported-by: Jens Axboe Tested-by: Jens Axboe Cc: Rob Clark Signed-off-by: Daniel Vetter Signed-off-by: Dave Airlie Signed-off-by: Greg Kroah-Hartman

drm: fix writing to /sys/class/drm/*/status

2015-06-05T22:27:30Z

Writing to a file is supposed to return the number of bytes written. Returning zero unfortunately causes bash to constantly spin trying to write to the sysfs file, to such an extent that even ^c and ^z have no effect. The only way out of that is to kill the shell and log back in. This isn't nice behaviour. Fix it by returning the number of characters written to sysfs files. [airlied: used suggestion from Al Viro] Signed-off-by: Russell King Reviewed-by: Chris Wilson Signed-off-by: Dave Airlie

drm: Lighten sysfs connector 'status'

2015-03-10T08:59:36Z

Since the beginning, sysfs/connector/status has done a heavyweight detection of the current connector status. But no user, such as upowerd or logind, has ever desired to initiate a probe. Move the probing into a new attribute so that existing readers get the behaviour they desire. v2: David Herrmann suggested using "echo detect > /sys/.../status" to trigger the probing, which is a fine idea. This extends that to also allow the user to apply the force detection overrides at runtime. v3: Now with airlied's email address fixed! Requires sysfs_streq() Signed-off-by: Chris Wilson Cc: Daniel Vetter Cc: David Herrmann Cc: Dave Airlie Cc: Alex Deucher Reviewed-by: David Herrmann Reviewed-by: Alex Deucher Signed-off-by: Daniel Vetter

drm: Use static attribute groups for managing connector sysfs entries

2015-02-04T14:02:00Z

Instead of manual calls of device_create_file() and device_remove_file(), assign the static attribute groups to the device with device_create_with_groups(). The conditionally built sysfs entries are handled via is_visible callback. This simplifies the code and also avoids the possible races. Signed-off-by: Takashi Iwai Signed-off-by: Daniel Vetter

drm: Move piles of functions from drmP.h to drm_internal.h

2014-09-12T09:16:29Z

This way drivers can't grow crazy ideas any more, and it also helps a bit in reviewing EXPORT_SYMBOLS. v2: Even more stuff. Unfortunately we can't move drm_vm_open_locked because exynos does some horrible stuff with it. Signed-off-by: Daniel Vetter

drm: make sysfs device always available for minors

2014-08-05T14:08:21Z

For each minor we allocate a sysfs device as minor->kdev. Currently, this is allocated and registered in drm_minor_register(). This makes it impossible to add sysfs-attributes to the device before it is registered. Therefore, they are not added atomically, nor can we move device_add() *after* ->load() is called. This patch makes minor->kdev available early, but only adds the device during minor-registration. Note that the registration is still called before ->load() as debugfs needs to be split, too. This will be fixed in follow-ups. Reviewed-by: Daniel Vetter Reviewed-by: Alex Deucher Signed-off-by: David Herrmann

drm: add register and unregister functions for connectors

2014-06-19T06:55:28Z

Introduce generic functions to register and unregister connectors. This provides a common place to add and remove associated user space interfaces. Signed-off-by: Thomas Wood Reviewed-by: David Herrmann Signed-off-by: Daniel Vetter

drm: replace drm_get_connector_name() with direct name field use

2014-06-04T03:17:41Z

Generated using semantic patch: @@ expression E; @@ - drm_get_connector_name(E) + E->name [airlied: regenerated] Acked-by: David Herrmann Signed-off-by: Jani Nikula Signed-off-by: Dave Airlie

drm/sysfs: fix OOM verification

2013-11-28T04:35:23Z

Copy/Paste typo.. we need to test for ->kdev instead of ->dev. Reported-by: Juha Leppänen Signed-off-by: David Herrmann Signed-off-by: Dave Airlie

drm/sysfs: fix hotplug regression since lifetime changes

2013-11-21T11:10:00Z

airlied: The lifetime changes introduced in 5bdebb183c9702a8c57a01dff09337be3de337a6 tried to use device_create, however that led to the regression where dev->type wasn't getting set correctly. First attempt at fixing it would have led to a race, so this undoes the device_createa work and does it all manually making sure the dev->type is setup before we register the device. Signed-off-by: David Herrmann Signed-off-by: Dave Airlie