[SRU,Xenial,1/1] Revert "ACPI / video: Add force_native quirk for HP Pavilion dv6"

From: Hans de Goede <hdegoede@redhat.com>

BugLink: http://bugs.launchpad.net/bugs/1667323

Revert commit 6276e53fa8c0 (ACPI / video: Add force_native quirk for
HP Pavilion dv6).

In the commit message for the quirk this revert removes I wrote:

"Note that there are quite a few HP Pavilion dv6 variants, some
woth ATI and some with NVIDIA hybrid gfx, both seem to need this
quirk to have working backlight control. There are also some versions
with only Intel integrated gfx, these may not need this quirk, but it
should not hurt there."

Unfortunately that seems wrong, I've already received 2 reports of
this commit causing regressions on some dv6 variants (at least one
of which actually has a nvidia GPU). So it seems that HP has made a
mess here by using the same model-name both in marketing and in the
DMI data for many different variants. Some of which need
acpi_backlight=native for functional backlight control (as the
quirk this commit reverts was doing), where as others are broken by
it. So lets get back to the old sitation so as to avoid regressing
on models which used to work without any kernel cmdline arguments
before.

Fixes: 6276e53fa8c0 (ACPI / video: Add force_native quirk for HP Pavilion dv6)
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit fd25ea29093e275195d0ae8b2573021a1c98959f)
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
---
 drivers/acpi/video_detect.c | 11 -----------
 1 file changed, 11 deletions(-)

On 10/04/17 13:37, Joseph Salisbury wrote:
> From: Hans de Goede <hdegoede@redhat.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/1667323
> 
> Revert commit 6276e53fa8c0 (ACPI / video: Add force_native quirk for
> HP Pavilion dv6).
> 
> In the commit message for the quirk this revert removes I wrote:
> 
> "Note that there are quite a few HP Pavilion dv6 variants, some
> woth ATI and some with NVIDIA hybrid gfx, both seem to need this
> quirk to have working backlight control. There are also some versions
> with only Intel integrated gfx, these may not need this quirk, but it
> should not hurt there."
> 
> Unfortunately that seems wrong, I've already received 2 reports of
> this commit causing regressions on some dv6 variants (at least one
> of which actually has a nvidia GPU). So it seems that HP has made a
> mess here by using the same model-name both in marketing and in the
> DMI data for many different variants. Some of which need
> acpi_backlight=native for functional backlight control (as the
> quirk this commit reverts was doing), where as others are broken by
> it. So lets get back to the old sitation so as to avoid regressing
> on models which used to work without any kernel cmdline arguments
> before.
> 
> Fixes: 6276e53fa8c0 (ACPI / video: Add force_native quirk for HP Pavilion dv6)
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> (cherry picked from commit fd25ea29093e275195d0ae8b2573021a1c98959f)
> Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
> ---
>  drivers/acpi/video_detect.c | 11 -----------
>  1 file changed, 11 deletions(-)
> 
> diff --git a/drivers/acpi/video_detect.c b/drivers/acpi/video_det`ect.c
> index b48ecbf..5e5e1ee 100644
> --- a/drivers/acpi/video_detect.c
> +++ b/drivers/acpi/video_detect.c
> @@ -280,17 +280,6 @@ static const struct dmi_system_id video_detect_dmi_table[] = {
>  		DMI_MATCH(DMI_PRODUCT_NAME, "Dell System XPS L702X"),
>  		},
>  	},
> -	{
> -	/* https://bugzilla.redhat.com/show_bug.cgi?id=1204476 */
> -	/* https://bugs.launchpad.net/ubuntu/+source/linux-lts-trusty/+bug/1416940 */
> -	.callback = video_detect_force_native,
> -	.ident = "HP Pavilion dv6",
> -	.matches = {
> -		DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
> -		DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dv6 Notebook PC"),
> -		},
> -	},
> -
>  	{ },
>  };
>  
> 
Sane looking bisect results, limited regression potential to just one
device and is an upstream fix, so:

Acked-by: Colin Ian King <colin.king@canonical.com>

Thanks Joe.