I get this warning in dmesg with the i915 driver: 0.854960] ------------[ cut here ]------------ [ 0.855026] WARNING: at fs/sysfs/dir.c:455 sysfs_add_one+0xbd/0xf0() [ 0.855091] Hardware name: Satellite L670 [ 0.855148] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight' [ 0.855247] Modules linked in: [ 0.855327] Pid: 1, comm: swapper Not tainted 3.1.0-rc3 #1 [ 0.855390] Call Trace: [ 0.855448] [<ffffffff81035dbb>] ? warn_slowpath_common+0x7b/0xc0 [ 0.855510] [<ffffffff81035eb5>] ? warn_slowpath_fmt+0x45/0x50 [ 0.855573] [<ffffffff8114229d>] ? sysfs_add_one+0xbd/0xf0 [ 0.855639] [<ffffffff81142d79>] ? create_dir+0x79/0xe0 [ 0.855701] [<ffffffff81142e52>] ? sysfs_create_dir+0x72/0xc0 [ 0.855781] [<ffffffff81177c15>] ? kobject_add_internal+0xb5/0x200 [ 0.855843] [<ffffffff81177f66>] ? kobject_add+0x46/0x70 [ 0.855908] [<ffffffff8126e649>] ? device_add+0xa9/0x6a0 [ 0.855970] [<ffffffff81028720>] ? complete_all+0x40/0x60 [ 0.856034] [<ffffffff811dea26>] ? backlight_device_register+0xf6/0x1d0 [ 0.856102] [<ffffffff8125e53f>] ? intel_panel_setup_backlight+0x6f/0xe0 [ 0.856169] [<ffffffff8124a629>] ? intel_modeset_init+0x7c9/0x10f0 [ 0.856233] [<ffffffff8122c861>] ? i915_driver_load+0xcd1/0x11d0 [ 0.856298] [<ffffffff811788e9>] ? kobject_uevent_env+0x1d9/0x480 [ 0.856364] [<ffffffff81219ada>] ? drm_get_minor+0x1aa/0x2b0 [ 0.856427] [<ffffffff8121bc58>] ? drm_get_pci_dev+0x198/0x2c0 [ 0.856495] [<ffffffff81278e6b>] ? __pm_runtime_set_status+0x18b/0x230 [ 0.856561] [<ffffffff81199625>] ? local_pci_probe+0x55/0xd0 [ 0.857217] [<ffffffff8119a52c>] ? pci_device_probe+0x8c/0xc0 [ 0.857284] [<ffffffff81270bb2>] ? driver_sysfs_add+0x72/0xa0 [ 0.857347] [<ffffffff81270cf6>] ? driver_probe_device+0x96/0x1c0 [ 0.857412] [<ffffffff81270eb3>] ? __driver_attach+0x93/0xa0 [ 0.857474] [<ffffffff81270e20>] ? driver_probe_device+0x1c0/0x1c0 [ 0.857541] [<ffffffff81270428>] ? bus_for_each_dev+0x58/0x80 [ 0.857604] [<ffffffff8126fce8>] ? bus_add_driver+0x198/0x260 [ 0.857671] [<ffffffff814f132a>] ? drm_core_init+0x108/0x108 [ 0.857732] [<ffffffff812714c0>] ? driver_register+0x70/0x130 [ 0.857801] [<ffffffff814f132a>] ? drm_core_init+0x108/0x108 [ 0.857865] [<ffffffff8119a7dc>] ? __pci_register_driver+0x4c/0xc0 [ 0.857930] [<ffffffff810001ca>] ? do_one_initcall+0x3a/0x170 [ 0.857999] [<ffffffff814d05b6>] ? kernel_init+0x90/0x10e [ 0.858062] [<ffffffff81350274>] ? kernel_thread_helper+0x4/0x10 [ 0.858126] [<ffffffff814d0526>] ? parse_early_options+0x20/0x20 [ 0.858190] [<ffffffff81350270>] ? gs_change+0xb/0xb [ 0.858254] ---[ end trace b2296b39a6e7298d ]--- [ 0.858314] kobject_add_internal failed for intel_backlight with -EEXIST, don't try to register things with the same name in the same directory. [ 0.858418] Pid: 1, comm: swapper Tainted: G W 3.1.0-rc3 #1 [ 0.858484] Call Trace: [ 0.858536] [<ffffffff81177cba>] ? kobject_add_internal+0x15a/0x200 [ 0.858601] [<ffffffff81177f66>] ? kobject_add+0x46/0x70 [ 0.858666] [<ffffffff8126e649>] ? device_add+0xa9/0x6a0 [ 0.858727] [<ffffffff81028720>] ? complete_all+0x40/0x60 [ 0.858795] [<ffffffff811dea26>] ? backlight_device_register+0xf6/0x1d0 [ 0.858861] [<ffffffff8125e53f>] ? intel_panel_setup_backlight+0x6f/0xe0 [ 0.858927] [<ffffffff8124a629>] ? intel_modeset_init+0x7c9/0x10f0 [ 0.858991] [<ffffffff8122c861>] ? i915_driver_load+0xcd1/0x11d0 [ 0.859054] [<ffffffff811788e9>] ? kobject_uevent_env+0x1d9/0x480 [ 0.859119] [<ffffffff81219ada>] ? drm_get_minor+0x1aa/0x2b0 [ 0.859184] [<ffffffff8121bc58>] ? drm_get_pci_dev+0x198/0x2c0 [ 0.859246] [<ffffffff81278e6b>] ? __pm_runtime_set_status+0x18b/0x230 [ 0.859312] [<ffffffff81199625>] ? local_pci_probe+0x55/0xd0 [ 0.859377] [<ffffffff8119a52c>] ? pci_device_probe+0x8c/0xc0 [ 0.859442] [<ffffffff81270bb2>] ? driver_sysfs_add+0x72/0xa0 [ 0.859506] [<ffffffff81270cf6>] ? driver_probe_device+0x96/0x1c0 [ 0.859571] [<ffffffff81270eb3>] ? __driver_attach+0x93/0xa0 [ 0.859637] [<ffffffff81270e20>] ? driver_probe_device+0x1c0/0x1c0 [ 0.859702] [<ffffffff81270428>] ? bus_for_each_dev+0x58/0x80 [ 0.859774] [<ffffffff8126fce8>] ? bus_add_driver+0x198/0x260 [ 0.859838] [<ffffffff814f132a>] ? drm_core_init+0x108/0x108 [ 0.859902] [<ffffffff812714c0>] ? driver_register+0x70/0x130 [ 0.859966] [<ffffffff814f132a>] ? drm_core_init+0x108/0x108 [ 0.860028] [<ffffffff8119a7dc>] ? __pci_register_driver+0x4c/0xc0 [ 0.860092] [<ffffffff810001ca>] ? do_one_initcall+0x3a/0x170 [ 0.860154] [<ffffffff814d05b6>] ? kernel_init+0x90/0x10e [ 0.860215] [<ffffffff81350274>] ? kernel_thread_helper+0x4/0x10 [ 0.860279] [<ffffffff814d0526>] ? parse_early_options+0x20/0x20 [ 0.860342] [<ffffffff81350270>] ? gs_change+0xb/0xb [ 0.860402] [drm:intel_panel_setup_backlight] *ERROR* Failed to register backlight: -17 It doesn't seems to cause a real problem but can somebody explain what's happening ?
A git bisect run reveals that the following commit is problematic; commit aaa6fd2a004147bf32fce05720938236de3361d9 Author: Matthew Garrett <mjg@redhat.com> Date: Fri Aug 12 12:11:33 2011 +0200 Not all systems expose a firmware or platform mechanism for changing the backlight intensity on i915, so add native driver support. Indeed, if I revert it, the problem doesn't occur.
First-Bad-Commit : aaa6fd2a004147bf32fce05720938236de3361d9
On Sunday, August 28, 2011, Dave Jones wrote: > On Sun, Aug 28, 2011 at 08:22:05PM +0200, Rafael J. Wysocki wrote: > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=41742 > > Subject : duplicate filename for intel_backlight with the i915 > driver > > Submitter : François Valenduc <francois.valenduc@tvcablenet.be> > > Date : 2011-08-25 18:51 (4 days old) > > First-Bad-Commit: > http://git.kernel.org/linus/aaa6fd2a004147bf32fce05720938236de3361d9 > > this should be fixed by b727d20269e8ef1de002bfea8099f5e9db9e9f23 > > Dave
On Sunday, August 28, 2011, Linus Torvalds wrote: > On Sun, Aug 28, 2011 at 12:35 PM, Dave Jones <davej@redhat.com> wrote: > > On Sun, Aug 28, 2011 at 08:22:05PM +0200, Rafael J. Wysocki wrote: > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=41742 > > > Subject : duplicate filename for intel_backlight with the > i915 driver > > > Submitter : François Valenduc <francois.valenduc@tvcablenet.be> > > > Date : 2011-08-25 18:51 (4 days old) > > > First-Bad-Commit: > http://git.kernel.org/linus/aaa6fd2a004147bf32fce05720938236de3361d9 > > > > this should be fixed by b727d20269e8ef1de002bfea8099f5e9db9e9f23 > > Actually, by a2cc797d2d1a ("i915: do not setup intel_backlight "). > > That b727d20269e is just my merge commit that brings in the fix (and > the bogus initialization of 'locked') into mainline. > > Linus