On Tue, 09 Jun 2015, Hans de Goede hdegoede@redhat.com wrote:
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@gmail.com Signed-off-by: Hans de Goede hdegoede@redhat.com
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);
Nitpick, I'd prefer positively named variables, like enable_foo to avoid the double negative !disable_foo. enable_foo and !enable_foo read much better. But up to Aaron and friends.
BR, Jani.
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
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