[U-Boot] [PATCH v2 0/19] tegra: Add display driver and LCD support for Seaboard

Stephen Warren swarren at wwwdotorg.org
Thu Jun 14 01:09:08 CEST 2012


On 06/13/2012 05:03 PM, Stephen Warren wrote:
> On 06/13/2012 04:57 PM, Stephen Warren wrote:
>> On 06/13/2012 10:19 AM, Simon Glass wrote:
>>> This series adds support for the Tegra2x's display peripheral. This
>>> supports the LCD display on Seaboard and we use this to enable console
>>> output in U-Boot on the LCD.
>>
>> Simon,
>>
>> This series doesn't apply to u-boot-tegra/master cleanly; there are a
>> couple trivial conflicts in arch/arm/cpu/armv7/tegra2/Makefile to
>> resolve, but I had to apply the final patch completely by hand.
>>
>> When I run the resultant binary, I see the LCD backlight turn on, but
>> the image on the LCD is wrong; it starts completely black without any
>> text showing, then slowly fills in to white/gray with many horizontal
>> and vertical black lines; I guess the LCD timing is incorrect - are
>> there multiple different LCD models? Note that I am using a real
>> Seaboard not a Springbank for this test.
> 
> Oh, false alarm on this second point - the LCD is screwed up after using
> nvflash to flash the device, but when power-cycling it rather than just
> resetting it, the LCD works fine. I guess this means the driver is not
> initializing something that nvflash changed, and relying on a power-on
> default. I suppose it might not be worth fixing that given it works from
> cold power on.

Oops, there is a problem - executing "reset" in U-Boot, or "reboot" from
the kernel (one without any display support at least; mainline Linux)
will get into the "bad LCD" state too. So, I guess there is something
that needs to be fixed.

Sorry for the back-to-back emails.


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