On Fri, 2009-04-24 at 14:15 +0800, Len Brown wrote: > On Fri, 24 Apr 2009, Zhang Rui wrote: > > > > > 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> > > --- > > drivers/acpi/video.c | 30 +++++++++++++++++++++++++++++- > > 1 file changed, 29 insertions(+), 1 deletion(-) > > > > Index: linux-2.6/drivers/acpi/video.c > > =================================================================== > > --- linux-2.6.orig/drivers/acpi/video.c > > +++ linux-2.6/drivers/acpi/video.c > > @@ -87,6 +87,8 @@ static const struct acpi_device_id video > > }; > > MODULE_DEVICE_TABLE(acpi, video_device_ids); > > > > +static int bqc_offset; > > + > > are there other machines with a similar bqc_offset AML bug? > well, the answer is no for now. > If no, then I'd rather this simple workaround be simpler > rather than be ready for a general case that will never happen... I don't think there is any place that we could make the code simpler. > > in any case, the code/comments should be clear that > this is a hideoous workaround rather than how things > are supposed to work. > eg call it bqc_offset_idiotic_aml_workaround or > something.. agree. refreshed patch attached. 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> --- drivers/acpi/video.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) Index: linux-2.6/drivers/acpi/video.c =================================================================== --- linux-2.6.orig/drivers/acpi/video.c +++ linux-2.6/drivers/acpi/video.c @@ -87,6 +87,12 @@ static const struct acpi_device_id video }; MODULE_DEVICE_TABLE(acpi, video_device_ids); +/* + * 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_idiotic_aml_workaround; + static struct acpi_driver acpi_video_bus = { .name = "video", .class = ACPI_VIDEO_CLASS, @@ -556,7 +562,8 @@ acpi_video_device_lcd_get_level_current( - 3 - (*level); *level = device->brightness->levels[*level + 2]; - } + } else if (bqc_offset_idiotic_aml_workaround) + *level += bqc_offset_idiotic_aml_workaround; device->brightness->curr = *level; return 0; } else { @@ -698,6 +705,29 @@ acpi_video_bus_DOS(struct acpi_video_bus return status; } +static int video_set_bqc_offset(const struct dmi_system_id *d) +{ + bqc_offset_idiotic_aml_workaround = 9; + return 0; +} + +static struct dmi_system_id video_dmi_table[] __initdata = { + /* + * Acer Aspire 5720 _BQC method is broken, + * it always returns a value smaller than the actual brightness level + * 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"), + }, + }, + {} +}; + /* * Simple comparison function used to sort backlight levels. */ @@ -2287,6 +2317,8 @@ EXPORT_SYMBOL(acpi_video_register); static int __init acpi_video_init(void) { + dmi_check_system(video_dmi_table); + if (intel_opregion_present()) return 0; -- 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
