Re: [PATCH] drm: tegra: Use framebuffer pitch as line stride

[Mark Zhang <nvmarkzhang-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On 11/28/2012 05:39 AM, Stephen Warren wrote:
> On 11/27/2012 11:17 AM, Stephen Warren wrote:
>> On 11/26/2012 08:16 PM, Mark Zhang wrote:
>>> On 11/27/2012 06:37 AM, Stephen Warren wrote:
>>>> On 11/22/2012 12:37 PM, Thierry Reding wrote:
>>>>> Instead of using the stride derived from the display mode, use the pitch
>>>>> associated with the currently active framebuffer. This fixes a bug where
>>>>> the LCD display content would be skewed when enabling HDMI with a video
>>>>> mode different from that of the LCD.
>>>>
>>>> This patch certainly doesn't cause any additional issues for me, so:
>>>>
>>>> Tested-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>>>>
>>>> Howwever, it still doesn't allow both Cardhu's LCD panel and external
>>>> HDMI port (1080p) to be active at once. If I boot with both enabled, or
>>>> boot with just the LCD enabled and hot-plug HDMI, as soon as both heads
>>>> are active, then some kind of display corruption starts; it looks like a
>>>> clocking issue or perhaps memory underflow.
>>>
>>> I haven't observed this issue. What kind of display corruption you mean?
>>> Did it recover after some seconds or the display in LVDS panel was
>>> always corrupted?
>>>
>>> During my testing, I connected HDMI while booting cardhu and I can see
>>> the LVDS and HDMI working with no corruptions.
>>
>> For your viewing pleasure (and playing with my new phone) :-)
>> http://www.youtube.com/watch?v=ZJxJnONz7DA
>>
>> The external monitor is 1920x1200 I believe.
> 
> Jon Mayo says the corruption in the video is display (memory fetch)
> underflow. Perhaps this is because (IIRC) the BCT I'm using on Cardhu
> programs the memory controller at a slow rate, and the bootloader and/or
> kernel is supposed to bump up the rate to the max, but that's not
> implemented anywhere yet upstream. If you're testing with "fastboot"
> instead of U-Boot, that might be re-programming the memory frequencies,
> and hence avoiding this.
> 

All right, I just test the framebuffer console and "xinit", I didn't
install the whole ubuntu.

I'll install the ubuntu in my cardhu and see whether I have this kind of
issues.

Mark
> I guess we have a fun time ahead of us with mode validation and memory
> controller programming.
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