Re: [PATCH] Platform: samsung-laptop: add DMI information for SamsungN150 Plus

[Corentin Chary]

On 12/26/2011 11:22 AM, David Herrmann wrote:
> On Mon, Dec 26, 2011 at 10:49 AM, Corentin Chary
> <corentin.chary@xxxxxxxxx>  wrote:
> > On Sat, Dec 24, 2011 at 3:28 PM, David Herrmann
> > <dh.herrmann@xxxxxxxxxxxxxx>  wrote:
> > > On Sat, Dec 24, 2011 at 3:20 PM, Matthew Garrett<mjg59@xxxxxxxxxxxxx>  wrote:
> > > > On Sat, Dec 24, 2011 at 02:12:57PM +0000, Andrzej Prochyra wrote:
> > > > > 'acpi_video0' not functional.  Brightness can be controlled through
> > > > > intel_backlight interface.  There are 21 brightness levels and the
> > > > > backlight can be turned off.
> > > >
> > > > If acpi_video0 doesn't work then we either need to work out why it's not
> > > > working or make it vanish completely, so this patch isn't the correct
> > > > approach.
> > >
> > > Just to make clear, intel_backlight isn't working properly either. If
> > > my laptop boots with backlight at 50% then intel_backlight will only
> > > work in the range 0%-50% on my machine. If I use the samsung module to
> > > set it to 100% then  intel_backlight works correctly in the range
> > > 0-100% until next reboot/suspend.
> > >
> > > So I'd recommend staying with the samsung module and disabling the
> > > acpi_backlight entirely. The samsung module is the only backlight
> > > control which works properly.
> >
> > Can I take a look at the DSDT to see how it's broken ?
> > If it's really not functional, then it should be added to the
> > blacklist in video_detect.c
>
> Raw and disassembled dsdt is attached.

Took a quick look but didn't find anything obvious. What happens exactly 
with acpi_video0 ?

But if it's not possible to make it work, I'd propose that (not tested):

diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_detect.c
index 45d8097..5041924 100644
--- a/drivers/acpi/video_detect.c
+++ b/drivers/acpi/video_detect.c
@@ -132,6 +132,26 @@ find_video(acpi_handle handle, u32 lvl, void 
*context, void **rv)
        return AE_OK;
 }

+/* Force to use vendor driver when the ACPI device is known to be
+ * buggy */
+static int video_detect_force_vendor(const struct dmi_system_id *d)
+{
+       acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
+}
+
+static struct dmi_system_id video_detect_dmi_table[] __initdata = {
+       {
+        .callback = video_detect_force_vendor,
+        .ident = "N150P",
+        .matches = {
+               DMI_MATCH(DMI_SYS_VENDOR,
+                         "SAMSUNG ELECTRONICS CO., LTD."),
+               DMI_MATCH(DMI_PRODUCT_NAME, "N150P"),
+               DMI_MATCH(DMI_BOARD_NAME, "N150P"),
+               },
+       },
+};
+
 /*
  * Returns the video capabilities of a specific ACPI graphics device
  *
@@ -164,6 +184,8 @@ long acpi_video_get_capabilities(acpi_handle 
graphics_handle)
                 *              ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
                 *}
                 */
+
+               dmi_check_system(video_detect_dmi_table);
        } else {
                status = acpi_bus_get_device(graphics_handle, &tmp_dev);
                if (ACPI_FAILURE(status)) {


--
Corentin Chary
http://xf.iksaif.net/
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