[U-Boot] [PATCH 2/2] video: tegra: refuse to bind to disabled dcs

[Simon Glass]

On 20 April 2016 at 07:16, Simon Glass <sjg at chromium.org> wrote:
> On 19 April 2016 at 16:19, Stephen Warren <swarren at wwwdotorg.org> wrote:
>> From: Stephen Warren <swarren at nvidia.com>
>>
>> This prevents the following boot-time message on any board where only the
>> first DC is in use, yet the DC's DT node is enabled:
>>
>> stdio_add_devices: Video device failed (ret=-22)
>>
>> (This happens on at least Harmony, Ventana, and likely any other Tegra20
>> board with display enabled other than Seaboard).
>>
>> The Tegra DC's DT node represents a display controller. It may itself
>> drive an integrated RGB display output, or be used by some other display
>> controller such as HDMI. For this reason the DC node itself is not
>> enabled/disabled in DT; the DC itself is considered a shared resource, not
>> the final (board-specific) display output. The node should instantiate a
>> display output driver only if the rgb subnode is enabled. Other output
>> drivers are free to use the DC if they are enabled and their DT node
>> references the DC's DT node. Adapt the Tegra display drivers' bind()
>> routine to only bind to the DC's DT node if the RGB subnode is enabled.
>>
>> Now that the display driver does the right thing, remove the workaround
>> for this issue from Seaboard's DT file.
>>
>> Cc: Thierry Reding <treding at nvidia.com>
>> Signed-off-by: Stephen Warren <swarren at nvidia.com>
>> ---
>> Thierry, I assume this is how the DC nodes are intended to be interpreted?
>> It's certainly how the kernel's DT files and driver work, even if by
>> accident.
>> ---
>> arch/arm/dts/tegra20-seaboard.dts | 4 ----
>> drivers/video/tegra.c | 7 +++++++
>> 2 files changed, 7 insertions(+), 4 deletions(-)
>
> Well it seems reasonable to me.
>
> Reviewed-by: Simon Glass <sjg at chromium.org>

Applied to u-boot-dm, thanks!