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ACPI video: dmi check for broken _BQC on Acer Aspire 5720

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On Acer Aspire 5720, _BQC always returns a value 9 smaller than
the actual brightness level.  Add dmi quirk for this laptop.

http://bugzilla.kernel.org/show_bug.cgi?id=13121

Tested-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Zhang Rui 2009-04-24 12:13:18 -04:00 committed by Len Brown
parent 0910697403
commit 45cb50e646
1 changed files with 30 additions and 0 deletions
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30
drivers/acpi/video.c
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@ -538,6 +538,33 @@ acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
return -EINVAL;
}
/*
* For some buggy _BQC methods, we need to add a constant value to
* the _BQC return value to get the actual current brightness level
*/
static int bqc_offset_aml_bug_workaround;
static int __init video_set_bqc_offset(const struct dmi_system_id *d)
{
bqc_offset_aml_bug_workaround = 9;
return 0;
}
static struct dmi_system_id video_dmi_table[] __initdata = {
/*
* Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
*/
{
.callback = video_set_bqc_offset,
.ident = "Acer Aspire 5720",
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
},
},
{}
};
static int
acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
unsigned long long *level)
@ -557,6 +584,7 @@ acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
*level = device->brightness->levels[*level + 2];
}
*level += bqc_offset_aml_bug_workaround;
device->brightness->curr = *level;
return 0;
} else {
@ -2287,6 +2315,8 @@ EXPORT_SYMBOL(acpi_video_register);
static int __init acpi_video_init(void)
{
dmi_check_system(video_dmi_table);
if (intel_opregion_present())
return 0;