On Thu, 2013-07-25 at 15:00 +0200, Rafael J. Wysocki wrote: > On Monday, July 22, 2013 09:54:21 PM Rafael J. Wysocki wrote: > > On Monday, July 22, 2013 11:11:54 AM Linus Torvalds wrote: > > > On Mon, Jul 22, 2013 at 6:02 AM, Rafael J. Wysocki <rjw@xxxxxxx> wrote: > > > > > > > > Linus, do you want me to send a pull request reverting 8c5bd7a and efaa14c? > > > > > > Yes, but let's wait a while. Not because I think we'll fix the problem > > > (hey, miracles might happen), but because I think it would be useful > > > to couple the reverts with information about the particular machines > > > that broke (and the people who reported it). So that when we > > > inevitably try again, we can perhaps get some testing effort with > > > those machines/people. > > > > > > It doesn't seem to be a show-stopped for a large number of people, so > > > there's no huge hurry. I'd suggest doing the revert just in time for > > > rc3, but waiting until then to gather info about people who see > > > breakage. > > > > > > Sound like a plan? > > > > Yes, it does. > > OK, time to revert I guess. > > James, Kamal, Steven, Jörg, Martin, Kalle, please check if the apppended patch > fixes the backlight for you. Yes, this revert patch does re-enable backlight control for the affected Dell XPS13 models. -Kamal > Aaron, please double check if acpi_video_backlight_quirks() will still work as > needed. > > Thanks, > Rafael > > > --- > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > Subject: Revert "ACPI / video / i915: No ACPI backlight if firmware expects Windows 8" > > We attempted to address a regression introduced by commit a57f7f9 > (ACPICA: Add Windows8/Server2012 string for _OSI method.) after which > ACPI video backlight support doesn't work on a number of systems, > because the relevant AML methods in the ACPI tables in their BIOSes > become useless after the BIOS has been told that the OS is compatible > with Windows 8. That problem is tracked by the bug entry at: > > https://bugzilla.kernel.org/show_bug.cgi?id=51231 > > Commit 8c5bd7a (ACPI / video / i915: No ACPI backlight if firmware > expects Windows 8) introduced for this purpose essentially prevented > the ACPI backlight support from being used if the BIOS had been told > that the OS was compatible with Windows 8 and the i915 driver was > loaded, in which case the backlight would always be handled by i915. > Unfortunately, however, that turned out to cause problems with > backlight to appear on multiple systems with symptoms indicating that > i915 was unable to control the backlight on those systems as > expected. > > For this reason, revert commit 8c5bd7a, but leave the function > acpi_video_backlight_quirks() introduced by it, because another > commit on top of it uses that function. > > References: https://lkml.org/lkml/2013/7/21/119 > References: https://lkml.org/lkml/2013/7/22/261 > References: https://lkml.org/lkml/2013/7/23/429 > References: https://lkml.org/lkml/2013/7/23/459 > References: https://lkml.org/lkml/2013/7/23/81 > References: https://lkml.org/lkml/2013/7/24/27 > Reported-by: James Hogan <james@xxxxxxxxxxxxx> > Reported-by: Steven Newbury <steve@xxxxxxxxxxxxxxx> > Reported-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx> > Reported-by: Martin Steigerwald <Martin@xxxxxxxxxxxx> > Reported-by: Jörg Otte <jrg.otte@xxxxxxxxx> > Reported-by: Kalle Valo <kvalo@xxxxxxxxxx> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > --- > drivers/acpi/internal.h | 2 - > drivers/acpi/video.c | 67 ++++------------------------------------ > drivers/acpi/video_detect.c | 15 -------- > drivers/gpu/drm/i915/i915_dma.c | 2 - > include/acpi/video.h | 11 ------ > include/linux/acpi.h | 1 > 6 files changed, 11 insertions(+), 87 deletions(-) > > Index: linux-pm/drivers/acpi/video.c > =================================================================== > --- linux-pm.orig/drivers/acpi/video.c > +++ linux-pm/drivers/acpi/video.c > @@ -897,7 +897,7 @@ static void acpi_video_device_find_cap(s > if (acpi_video_init_brightness(device)) > return; > > - if (acpi_video_verify_backlight_support()) { > + if (acpi_video_backlight_support()) { > struct backlight_properties props; > struct pci_dev *pdev; > acpi_handle acpi_parent; > @@ -1344,8 +1344,8 @@ acpi_video_switch_brightness(struct acpi > unsigned long long level_current, level_next; > int result = -EINVAL; > > - /* no warning message if acpi_backlight=vendor or a quirk is used */ > - if (!acpi_video_verify_backlight_support()) > + /* no warning message if acpi_backlight=vendor is used */ > + if (!acpi_video_backlight_support()) > return 0; > > if (!device->brightness) > @@ -1843,46 +1843,6 @@ static int acpi_video_bus_remove(struct > return 0; > } > > -static acpi_status video_unregister_backlight(acpi_handle handle, u32 lvl, > - void *context, void **rv) > -{ > - struct acpi_device *acpi_dev; > - struct acpi_video_bus *video; > - struct acpi_video_device *dev, *next; > - > - if (acpi_bus_get_device(handle, &acpi_dev)) > - return AE_OK; > - > - if (acpi_match_device_ids(acpi_dev, video_device_ids)) > - return AE_OK; > - > - video = acpi_driver_data(acpi_dev); > - if (!video) > - return AE_OK; > - > - acpi_video_bus_stop_devices(video); > - mutex_lock(&video->device_list_lock); > - list_for_each_entry_safe(dev, next, &video->video_device_list, entry) { > - if (dev->backlight) { > - backlight_device_unregister(dev->backlight); > - dev->backlight = NULL; > - kfree(dev->brightness->levels); > - kfree(dev->brightness); > - } > - if (dev->cooling_dev) { > - sysfs_remove_link(&dev->dev->dev.kobj, > - "thermal_cooling"); > - sysfs_remove_link(&dev->cooling_dev->device.kobj, > - "device"); > - thermal_cooling_device_unregister(dev->cooling_dev); > - dev->cooling_dev = NULL; > - } > - } > - mutex_unlock(&video->device_list_lock); > - acpi_video_bus_start_devices(video); > - return AE_OK; > -} > - > static int __init is_i740(struct pci_dev *dev) > { > if (dev->device == 0x00D1) > @@ -1914,25 +1874,14 @@ static int __init intel_opregion_present > return opregion; > } > > -int __acpi_video_register(bool backlight_quirks) > +int acpi_video_register(void) > { > - bool no_backlight; > - int result; > - > - no_backlight = backlight_quirks ? acpi_video_backlight_quirks() : false; > - > + int result = 0; > if (register_count) { > /* > - * If acpi_video_register() has been called already, don't try > - * to register acpi_video_bus, but unregister backlight devices > - * if no backlight support is requested. > + * if the function of acpi_video_register is already called, > + * don't register the acpi_vide_bus again and return no error. > */ > - if (no_backlight) > - acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, > - ACPI_UINT32_MAX, > - video_unregister_backlight, > - NULL, NULL, NULL); > - > return 0; > } > > @@ -1948,7 +1897,7 @@ int __acpi_video_register(bool backlight > > return 0; > } > -EXPORT_SYMBOL(__acpi_video_register); > +EXPORT_SYMBOL(acpi_video_register); > > void acpi_video_unregister(void) > { > Index: linux-pm/drivers/gpu/drm/i915/i915_dma.c > =================================================================== > --- linux-pm.orig/drivers/gpu/drm/i915/i915_dma.c > +++ linux-pm/drivers/gpu/drm/i915/i915_dma.c > @@ -1648,7 +1648,7 @@ int i915_driver_load(struct drm_device * > if (INTEL_INFO(dev)->num_pipes) { > /* Must be done after probing outputs */ > intel_opregion_init(dev); > - acpi_video_register_with_quirks(); > + acpi_video_register(); > } > > if (IS_GEN5(dev)) > Index: linux-pm/include/acpi/video.h > =================================================================== > --- linux-pm.orig/include/acpi/video.h > +++ linux-pm/include/acpi/video.h > @@ -17,21 +17,12 @@ struct acpi_device; > #define ACPI_VIDEO_DISPLAY_LEGACY_TV 0x0200 > > #if (defined CONFIG_ACPI_VIDEO || defined CONFIG_ACPI_VIDEO_MODULE) > -extern int __acpi_video_register(bool backlight_quirks); > -static inline int acpi_video_register(void) > -{ > - return __acpi_video_register(false); > -} > -static inline int acpi_video_register_with_quirks(void) > -{ > - return __acpi_video_register(true); > -} > +extern int acpi_video_register(void); > extern void acpi_video_unregister(void); > extern int acpi_video_get_edid(struct acpi_device *device, int type, > int device_id, void **edid); > #else > static inline int acpi_video_register(void) { return 0; } > -static inline int acpi_video_register_with_quirks(void) { return 0; } > static inline void acpi_video_unregister(void) { return; } > static inline int acpi_video_get_edid(struct acpi_device *device, int type, > int device_id, void **edid) > Index: linux-pm/drivers/acpi/video_detect.c > =================================================================== > --- linux-pm.orig/drivers/acpi/video_detect.c > +++ linux-pm/drivers/acpi/video_detect.c > @@ -235,12 +235,7 @@ static void acpi_video_caps_check(void) > > bool acpi_video_backlight_quirks(void) > { > - if (acpi_gbl_osi_data >= ACPI_OSI_WIN_8) { > - acpi_video_caps_check(); > - acpi_video_support |= ACPI_VIDEO_SKIP_BACKLIGHT; > - return true; > - } > - return false; > + return acpi_gbl_osi_data >= ACPI_OSI_WIN_8; > } > EXPORT_SYMBOL(acpi_video_backlight_quirks); > > @@ -288,14 +283,6 @@ int acpi_video_backlight_support(void) > } > EXPORT_SYMBOL(acpi_video_backlight_support); > > -/* For the ACPI video driver use only. */ > -bool acpi_video_verify_backlight_support(void) > -{ > - return (acpi_video_support & ACPI_VIDEO_SKIP_BACKLIGHT) ? > - false : acpi_video_backlight_support(); > -} > -EXPORT_SYMBOL(acpi_video_verify_backlight_support); > - > /* > * Use acpi_backlight=vendor/video to force that backlight switching > * is processed by vendor specific acpi drivers or video.ko driver. > Index: linux-pm/include/linux/acpi.h > =================================================================== > --- linux-pm.orig/include/linux/acpi.h > +++ linux-pm/include/linux/acpi.h > @@ -191,7 +191,6 @@ extern bool wmi_has_guid(const char *gui > #define ACPI_VIDEO_BACKLIGHT_DMI_VIDEO 0x0200 > #define ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VENDOR 0x0400 > #define ACPI_VIDEO_OUTPUT_SWITCHING_DMI_VIDEO 0x0800 > -#define ACPI_VIDEO_SKIP_BACKLIGHT 0x1000 > > #if defined(CONFIG_ACPI_VIDEO) || defined(CONFIG_ACPI_VIDEO_MODULE) > > Index: linux-pm/drivers/acpi/internal.h > =================================================================== > --- linux-pm.orig/drivers/acpi/internal.h > +++ linux-pm/drivers/acpi/internal.h > @@ -169,10 +169,8 @@ int acpi_create_platform_device(struct a > -------------------------------------------------------------------------- */ > #if defined(CONFIG_ACPI_VIDEO) || defined(CONFIG_ACPI_VIDEO_MODULE) > bool acpi_video_backlight_quirks(void); > -bool acpi_video_verify_backlight_support(void); > #else > static inline bool acpi_video_backlight_quirks(void) { return false; } > -static inline bool acpi_video_verify_backlight_support(void) { return false; } > #endif > > #endif /* _ACPI_INTERNAL_H_ */ >
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