From: Zhang Rui <rui.zhang@xxxxxxxxx> Subject: [PATCH] ACPI video: dmi check for broken _BQC on Acer Aspire 5720 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@xxxxxxxxx> Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx> Signed-off-by: Len Brown <len.brown@xxxxxxxxx> --- we can add __init to video_set_bqc_offset we can delete the flag used to guard the add, and simply add 0 on non-workaround machines. we can move the use up with the definition, say, like this? thanks, -Len drivers/acpi/video.c | 30 ++++++++++++++++++++++++++++++ 1 files changed, 30 insertions(+), 0 deletions(-) diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index cd4fb75..7e8ee49 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -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; -- 1.6.3.rc1.51.gea0b7 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
