kernel/drivers/gpu/drm/drm_drv.c, branch linux-4.16.y

drm: Match sysfs name in link removal to link creation

2018-05-22T16:56:22Z

commit 7f6df440b8623c441c42d070bf592e2d2c1fa9bb upstream. This patch matches the sysfs name used in the unlinking with the linking function. Otherwise, remove_compat_control_link() fails to remove sysfs created by create_compat_control_link() in drm_dev_register(). Fixes: 6449b088dd51 ("drm: Add fake controlD* symlinks for backwards compat") Cc: Dave Airlie Cc: Alex Deucher Cc: Emil Velikov Cc: David Herrmann Cc: Greg Kroah-Hartman Cc: Daniel Vetter Cc: Gustavo Padovan Cc: Maarten Lankhorst Cc: Sean Paul Cc: David Airlie Cc: dri-devel@lists.freedesktop.org Cc: # v4.10+ Signed-off-by: Haneen Mohammed [seanpaul added Fixes and Cc tags] Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/20180511041542.GA4253@haneen-vb Signed-off-by: Greg Kroah-Hartman

Merge airlied/drm-next into drm-misc-next

2017-11-21T13:17:56Z

Bake in the conflict between the drm_print.h extraction and the addition of DRM_DEBUG_LEASES since we lost it a few too many times. Also fix a new use of drm_plane_helper_check_state in msm to follow Ville's conversion in commit a01cb8ba3f6282934cff65e89ab36b18b14cbe27 Author: Ville Syrjälä Date: Wed Nov 1 22:16:19 2017 +0200 drm: Move drm_plane_helper_check_state() into drm_atomic_helper.c Acked-by: Ville Syrjälä Signed-off-by: Daniel Vetter

drm: Add new LEASE debug level

2017-10-25T06:31:29Z

Separate out lease debugging from the core. Signed-off-by: Keith Packard Signed-off-by: Dave Airlie

drm: Move debug macros out of drmP.h

2017-10-20T17:14:48Z

This patch extract DRM_* debug macros from drmP.h to drm_print.h and move printing related functions used by these macros from drm_drv.[hc] to drm_print.[hc]. Signed-off-by: Haneen Mohammed Signed-off-by: Sean Paul Link: https://patchwork.freedesktop.org/patch/msgid/4020bc7c5ffad2af516919f78bb837c7f366b82b.1508297716.git.hamohammed.sa@gmail.com

drm: introduce drm_dev_{get/put} functions

2017-09-26T11:12:15Z

Reference counting functions in the kernel typically use get/put suffixes. For maintaining coding style consistency, introduce drm_dev_{get/put} functions. All callers of drm_dev_ref() API have been converted in this patch and hence it has been dropped while the drm_dev_unref() API with non-trivial number of users remains for compatibility. The semantic patch scripts/coccinelle/api/drm-get-put.cocci has been updated with the new helper for conversion of drm_dev_unref() to drm_dev_put() Signed-off-by: Aishwarya Pant Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/6babda56134035a98220d5d37a4fd4048df214ce.1506413698.git.aishpant@gmail.com

drm: Clean up drm_dev_unplug

2017-08-11T08:49:21Z

Use drm_dev_unregister to unregister the interfaces, which also allows us to simplify the open_count == 0 case. Reviewed-by: Alex Deucher Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20170802115604.12734-5-daniel.vetter@ffwll.ch

drm: Only lastclose on unload for legacy drivers

2017-08-11T08:48:12Z

The only thing modern drivers are supposed to do in lastclose is restore the fb emulation state. Which is entirely optional, and there's really no reason to do that. So restrict it to legacy drivers (where the driver cleanup essentially happens in lastclose). This will also allow us to share the unregister function with drm_dev_unplug(). Quoting my reply to Alex on dri-devel: On Thu, Aug 3, 2017 at 1:17 AM, Daniel Vetter wrote: > On Wed, Aug 2, 2017 at 10:50 PM, Alex Deucher wrote: >> On Wed, Aug 2, 2017 at 7:56 AM, Daniel Vetter wrote: >>> The only thing modern drivers are supposed to do in lastclose is >>> restore the fb emulation state. Which is entirely optional, and >>> there's really no reason to do that. So restrict it to legacy drivers >>> (where the driver cleanup essentially happens in lastclose). >> >> vga_switcheroo_process_delayed_switch() gets called in lastclose. >> Won't that need to get moved elsewhere for this to work? > > Hm right, I forgot the lazy way to do runtime pm by keeping the device > alive as long as anyone has an open fd for it ... This shouldn't be a > problem, since you need to unregister from vgaswitcheroo anyway on > unload. Maybe that blows up, I'll check the code and augment the patch > as needed. So I think there's 3 cases: - Trying to unload the module. You can't do that while anyone has the fd still open, so lastclose is guaranteeed to run. - Forcefully unbinding the driver through sysfs. Not any better, since the can_switch stuff checks for the open count, and so will delay the delayed switch no matter what. - Actual hotremoval: a) not implemented since none of the drivers taking part in vgaswitcheroo correctly unplug the drm device and b) you can't hotremove a chip from a laptop. v2: Extend commit message with m-l discussion. Reviewed-by: Alex Deucher Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20170802115604.12734-4-daniel.vetter@ffwll.ch

drm: Document device unplug infrastructure

2017-08-11T08:48:03Z

While at it, also ocd and give them a consistent drm_dev_ prefix, like the other device instance functionality. Plus move the functions into the right places. Reviewed-by: Alex Deucher Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20170802115604.12734-3-daniel.vetter@ffwll.ch

drm: inhibit drm drivers register to uninitialized drm core

2017-07-11T10:03:11Z

If the DRM core fails to init for whatever reason, ensure that no driver ever calls drm_dev_register(). This is best done at drm_dev_init() as it covers drivers that call drm_dev_alloc() as well as drivers that prefer to embed struct drm_device into their own device struct and call drm_dev_init() themselves. In my case I had so many dynamic device majors used that the major number for DRM (226) was stolen, causing DRM core init to fail after failing to register a chrdev, and ultimately calling debugfs_remove() on drm_debugfs_root in drm_core_exit(). After drm core failed to init, VGEM was still calling drm_dev_register(), ultimately leading to drm_debugfs_init(), with drm_debugfs_root passed as the root for the new debugfs dir at debugfs_create_dir(). This led to a kernel panic once we were either derefencing root->d_inode while it was NULL or calling root->d_inode->i_op->lookup() while it was NULL in debugfs at inode_lock() or lookup_*(). Signed-off-by: Alexandru Moise <00moses.alexander00@gmail.com> Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20170708214352.GA27205@gmail.com

drm: Fix oops + Xserver hang when unplugging USB drm devices

2017-06-02T15:09:35Z

commit a39be606f99d ("drm: Do a full device unregister when unplugging") causes backtraces like this one when unplugging an usb drm device while it is in use: usb 2-3: USB disconnect, device number 25 ------------[ cut here ]------------ WARNING: CPU: 0 PID: 242 at drivers/gpu/drm/drm_mode_config.c:424 drm_mode_config_cleanup+0x220/0x280 [drm] ... RIP: 0010:drm_mode_config_cleanup+0x220/0x280 [drm] ... Call Trace: gm12u320_modeset_cleanup+0xe/0x10 [gm12u320] gm12u320_driver_unload+0x35/0x70 [gm12u320] drm_dev_unregister+0x3c/0xe0 [drm] drm_unplug_dev+0x12/0x60 [drm] gm12u320_usb_disconnect+0x36/0x40 [gm12u320] usb_unbind_interface+0x72/0x280 device_release_driver_internal+0x158/0x210 device_release_driver+0x12/0x20 bus_remove_device+0x104/0x180 device_del+0x1d2/0x350 usb_disable_device+0x9f/0x270 usb_disconnect+0xc6/0x260 ... [drm:drm_mode_config_cleanup [drm]] *ERROR* connector Unknown-1 leaked! ------------[ cut here ]------------ WARNING: CPU: 0 PID: 242 at drivers/gpu/drm/drm_mode_config.c:458 drm_mode_config_cleanup+0x268/0x280 [drm] ... ---[ end trace 80df975dae439ed6 ]--- general protection fault: 0000 [#1] SMP ... Call Trace: ? __switch_to+0x225/0x450 drm_mode_rmfb_work_fn+0x55/0x70 [drm] process_one_work+0x193/0x3c0 worker_thread+0x4a/0x3a0 ... RIP: drm_framebuffer_remove+0x62/0x3f0 [drm] RSP: ffffb776c39dfd98 ---[ end trace 80df975dae439ed7 ]--- After which the system is unusable this is caused by drm_dev_unregister getting called immediately on unplug, which calls the drivers unload function which calls drm_mode_config_cleanup which removes the framebuffer object while userspace is still holding a reference to it. Reverting commit a39be606f99d ("drm: Do a full device unregister when unplugging") leads to the following oops on unplug instead, when userspace closes the last fd referencing the drm_dev: sysfs group 'power' not found for kobject 'card1-Unknown-1' ------------[ cut here ]------------ WARNING: CPU: 0 PID: 2459 at fs/sysfs/group.c:237 sysfs_remove_group+0x80/0x90 ... RIP: 0010:sysfs_remove_group+0x80/0x90 ... Call Trace: dpm_sysfs_remove+0x57/0x60 device_del+0xfd/0x350 device_unregister+0x1a/0x60 drm_sysfs_connector_remove+0x39/0x50 [drm] drm_connector_unregister+0x5a/0x70 [drm] drm_connector_unregister_all+0x45/0xa0 [drm] drm_modeset_unregister_all+0x12/0x30 [drm] drm_dev_unregister+0xca/0xe0 [drm] drm_put_dev+0x32/0x60 [drm] drm_release+0x2f3/0x380 [drm] __fput+0xdf/0x1e0 ... ---[ end trace ecfb91ac85688bbe ]--- BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8 IP: down_write+0x1f/0x40 ... Call Trace: debugfs_remove_recursive+0x55/0x1b0 drm_debugfs_connector_remove+0x21/0x40 [drm] drm_connector_unregister+0x62/0x70 [drm] drm_connector_unregister_all+0x45/0xa0 [drm] drm_modeset_unregister_all+0x12/0x30 [drm] drm_dev_unregister+0xca/0xe0 [drm] drm_put_dev+0x32/0x60 [drm] drm_release+0x2f3/0x380 [drm] __fput+0xdf/0x1e0 ... ---[ end trace ecfb91ac85688bbf ]--- This is caused by the revert moving back to drm_unplug_dev calling drm_minor_unregister which does: device_del(minor->kdev); dev_set_drvdata(minor->kdev, NULL); /* safety belt */ drm_debugfs_cleanup(minor); Causing the sysfs entries to already be removed even though we still have references to them in e.g. drm_connector. Note we must call drm_minor_unregister to notify userspace of the unplug of the device, so calling drm_dev_unregister is not completely wrong the problem is that drm_dev_unregister does too much. This commit fixes drm_unplug_dev by not only reverting commit a39be606f99d ("drm: Do a full device unregister when unplugging") but by also adding a call to drm_modeset_unregister_all before the drm_minor_unregister calls to make sure all sysfs entries are removed before calling device_del(minor->kdev) thereby also fixing the second set of oopses caused by just reverting the commit. Fixes: a39be606f99d ("drm: Do a full device unregister when unplugging") Cc: stable@vger.kernel.org Cc: Chris Wilson Cc: Jeffy Cc: Marco Diego Aurélio Mesquita Reported-by: Marco Diego Aurélio Mesquita Signed-off-by: Hans de Goede Reviewed-by: Chris Wilson Signed-off-by: Sean Paul Link: http://patchwork.freedesktop.org/patch/msgid/20170601115430.4113-1-hdegoede@redhat.com