Re: [PATCH] drm/kms: fix fbdev blanking regression

From: James Simmons
Date: Tue Jan 12 2010 - 12:29:18 EST



> On 01/07/2010 12:42 AM, Johan Hovold wrote:
> >> Yeap. The fix uncovered a bug in your driver. I haven't heard of problems
> >> with the other drm drivers.
> >>
> >>> The backlight is handled via the DRI driver I assume. At least
> >>> i9xx_crtc_dpms is called on powerdown.
> >>
> >> Can you post your dmesg and kernel config.
>
> [snip]
>
> Adding the Intel DRM people in CC as well. I have the same issue with my
> GM45.

Okay I looked at the code to figure out what is happening and why only
this driver has problems. The problem is that the framebuffer layer
expects the backlight to be a seperate device. The reason being is that
some embedded systems will use a gpio backlight. That way power management
for a graphics card/backlight has 3 seperate states. Currently the intel
DRM driver treats the backlight as being apart of the encoder. Jesse do
you have objections to having the intel driver expose a backlight device.
The bonus of that is the user can also set the backlight levels.


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