On some systems acpi-video backlight is broken in the sense that it cannot control the brightness of the backlight, but it must still be called on resume to power-up the backlight after resume. This commit allows these systems to work by going through all the usual backlight control moves, while not registering a sysfs backlight interface. This commit also adds a quirk enabling this parameter on Toshiba Portege R830 systems which are known to be affected by this. I wish there was a better way to deal with this, but we've been unable to find one. Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=21012 Buglink: https://bugs.freedesktop.org/show_bug.cgi?id=82634 Reported-and-tested-by: Sylvain Pasche <sylvain.pasche@xxxxxxxxx> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> --- Changes in v2: -Simplify check in acpi_video_switch_brightness() -If backlight registration fails set device->backlight to NULL, rather then leaving the PTR_ERR in there and trying to deref this later (this fixes a pre-existing bug) --- drivers/acpi/video.c | 43 +++++++++++++++++++++++++++++++++++++++---- 1 file changed, 39 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index 518f0e1..3bc4c68 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -92,6 +92,9 @@ static int use_native_backlight_param = NATIVE_BACKLIGHT_NOT_SET; module_param_named(use_native_backlight, use_native_backlight_param, int, 0444); static int use_native_backlight_dmi = NATIVE_BACKLIGHT_NOT_SET; +static int disable_backlight_sysfs_if = -1; +module_param(disable_backlight_sysfs_if, int, 0444); + static int register_count; static struct mutex video_list_lock; static struct list_head video_bus_head; @@ -431,6 +434,14 @@ static int __init video_enable_native_backlight(const struct dmi_system_id *d) return 0; } +static int __init video_disable_backlight_sysfs_if( + const struct dmi_system_id *d) +{ + if (disable_backlight_sysfs_if == -1) + disable_backlight_sysfs_if = 1; + return 0; +} + static struct dmi_system_id video_dmi_table[] __initdata = { /* * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121 @@ -592,6 +603,23 @@ static struct dmi_system_id video_dmi_table[] __initdata = { DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"), }, }, + + /* + * Some machines have a broken acpi-video interface for brightness + * control, but still need an acpi_video_device_lcd_set_level() call + * on resume to turn the backlight power on. We Enable backlight + * control on these systems, but do not register a backlight sysfs + * as brightness control does not work. + */ + { + /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */ + .callback = video_disable_backlight_sysfs_if, + .ident = "Toshiba Portege R830", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"), + DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"), + }, + }, {} }; @@ -1391,7 +1419,7 @@ acpi_video_switch_brightness(struct work_struct *work) int result = -EINVAL; /* no warning message if acpi_backlight=vendor or a quirk is used */ - if (!acpi_video_verify_backlight_support()) + if (!device->backlight) return; if (!device->brightness) @@ -1666,8 +1694,9 @@ static int acpi_video_resume(struct notifier_block *nb, for (i = 0; i < video->attached_count; i++) { video_device = video->attached_array[i].bind_info; - if (video_device && video_device->backlight) - acpi_video_set_brightness(video_device->backlight); + if (video_device && video_device->brightness) + acpi_video_device_lcd_set_level(video_device, + video_device->brightness->curr); } return NOTIFY_OK; @@ -1716,6 +1745,10 @@ static void acpi_video_dev_register_backlight(struct acpi_video_device *device) result = acpi_video_init_brightness(device); if (result) return; + + if (disable_backlight_sysfs_if > 0) + return; + name = kasprintf(GFP_KERNEL, "acpi_video%d", count); if (!name) return; @@ -1738,8 +1771,10 @@ static void acpi_video_dev_register_backlight(struct acpi_video_device *device) &acpi_backlight_ops, &props); kfree(name); - if (IS_ERR(device->backlight)) + if (IS_ERR(device->backlight)) { + device->backlight = NULL; return; + } /* * Save current brightness level in case we have to restore it -- 2.4.2 -- To unsubscribe from this list: send the line "unsubscribe platform-driver-x86" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
