[U-Boot] [PATCH v2 00/23] dm: tegra: Convert tegra20 and tegra124 video drivers to driver model

Simon Glass sjg at chromium.org
Tue Feb 2 01:05:54 CET 2016


Hi Stephen,

On 1 February 2016 at 17:00, Stephen Warren <swarren at wwwdotorg.org> wrote:
> On 01/30/2016 04:37 PM, Simon Glass wrote:
>>
>> This series moves these two drivers over to use driver model for video.
>>
>> This involves the following steps:
>> - Sync up some device tree files with Linux
>> - Implement a proper PWM driver
>> - Clean up and unify the driver code
>> - Modify the existing drivers to work with driver model
>>
>> The tegra20 display driver uses device tree bindings invented in 2011
>> before
>> Linux had this or anyone was able to agree a standard. It seems possible
>> to
>> move it to the new bindings (like tegra124) except for the issue of time
>> delays between stages. It isn't clear how this should work, and Linux
>> implements this by including all LCD definitions in the kernel source
>> code,
>> and not using any delays. This causes strange display artifacts on the
>> display when starting up, but perhaps is harmless to the display. Future
>> work will sync up the device tree more for seaboard, and thus tidy this up
>> for nvidia boards.
>>
>> A bug in the keyboard driver is also fixed by this series. The series is
>> tested on seaboard and nyan-big, the two boards I have which support a
>> display.
>>
>> This series is available at u-boot-dm/tegra-working.
>
>
> This changes the name of the output device from "lcd" to "vidconsole".
> Anyone who doesn't reset their environment to default when switching to this
> new U-Boot will lose their display output because of this. Is there any way
> to maintain compatibility?

I could not think of one other than an egregious hack. It will
certainly bite someone. Perhaps a hack that detects 'lcd' in the
stdout env variable and prints a warning would be useful?

>
> Aside from that, I don't see any issues on Springbank (Seaboard), Harmony,
> Ventana, Paz00, or p2371-2180, so the series,
> Tested-by: Stephen Warren <swarren at nvidia.com>

Thanks very much for testing all those,.

Regards,
Simon


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