Commit 654a182d authored by Hans de Goede's avatar Hans de Goede Committed by Rafael J. Wysocki
Browse files

ACPI / video: Add a parameter to not register the backlight sysfs interface 

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.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=21012
Link: https://bugs.freedesktop.org/show_bug.cgi?id=82634


Reported-and-tested-by: default avatarSylvain Pasche <sylvain.pasche@gmail.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Acked-by: default avatarAaron Lu <aaron.lu@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 7f5c1882

drivers/acpi/video.c

+39 −4
Original line number Diff line number Diff line
@@ -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

CRA Git | Maintained and supported by SUSTech CRA and CCSE