Re: i830 watermark problems - status?

Thomas Richter
2013-11-25T15:56:23Z

Am 25.11.2013 16:23, schrieb Daniel Vetter:
> On Mon, Nov 25, 2013 at 04:14:12PM +0100, Thomas Richter wrote:
>> Hi Daniel, hi group,
>>
>> just being curious - what is the status of the i830 watermark
>> problems, i.e. the state of affairs
>> concerning that the i830 does not allow the maximum watermark value,
>> but requires a "headroom" of eight entries to
>> avoid flickering.
>>
>> I provided a patch for this a while ago, but this seems to go
>> nowhere. Just to remind you: The current code does not create
>> a stable image on i830 based devices, even if only an internal
>> display is connected.
>>
>> I provided two possible attacks to the problem: A quick and dirty
>> method which checks for the maximum value for
>> i830 manually, or an overall solution which adds a "minimum"
>> watermark value for all supported chipsets.
>>
>> Please let me know how to proceed.
> I seem to be too swamped with firedrills and bugs atm to get the polished
> version in. The problem with just a quick hack is that we still need to
> switch i830M to the dual-pipe watermark function, and somehow my patch to
> do so seems to be broken. At least you've said that the kernel still seems
> to hit the single-watermark version of the function.
>
> So atm I'm a bit stalled on this :( But if you can track this down I'd go
> with a quick hack to enforce the minimum of 8 or so in the dual-pipe
> watermark function shared by gen2/3.

Not a problem on my side, but it would be a "bad thing"(tm) to release a
kernel that leaves a i830 based
architecture essentially non-usable. Well, if you depend on a local
display, that is. (-;

Greetings,
Thomas