Re: [3.0-rc1] i915: blank screen on Lenovo Ideapad U160

[Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de>]

"Robert P. J. Day" <rpjday@crashcourse.ca> writes:

> On Tue, 31 May 2011, Dirk Gouders wrote:
>
>> Hello,
>>
>> I tested 3.0.0-rc1 on my notebook which has never been the best friend
>> of the i915 driver.  With linux-2.6.38-gentoo-r4 it has the problem
>> that the screen remains blank after the lid is closed and reopened, but
>> that problem I can live with.  With 3.0.0-r1 I am back to a former
>> problem that the screen goes (and remains) blank while booting.
>>
>> The next step I will do is to test linux-2.6.39-gentoo, probably I
>> did not notice information that I have to adjust boot parameters or the
>> kernel config?
>
>   based on my having lived through the i915 "black screen of death",
> pulling out my handy "git bisect" and with advice from chris wilson,
> these days, i simply apply this patch to the source:
>
> diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c
> index d2c7104..a1a5d03 100644
> --- a/drivers/gpu/drm/i915/intel_opregion.c
> +++ b/drivers/gpu/drm/i915/intel_opregion.c
> @@ -152,6 +152,8 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
>  	struct opregion_asle *asle = dev_priv->opregion.asle;
>  	u32 max;
>
> +return ASLE_BACKLIGHT_FAILED; // rday
> +
>  	if (!(bclp & ASLE_BCLP_VALID))
>  		return ASLE_BACKLIGHT_FAILED;
>
>
>   i tried taking it out a couple of times and immediately got the same
> i915-related problem so until i hear differently, the patch stays in.

Thanks for the hint.  I tested the patch with 3.0.0-rc1 and
unfortunately the symptoms remain the same.

Meanwhile, I tested 2.6.39-gentoo as well and it also causes that
problem.  So, this is not really a (new) 3.0.0-rc1 issue.

Best regards,

Dirk