[PATCH v4 00/11] drm: add support for Atmel HLCDC Display Controller

Boris BREZILLON boris.brezillon at free-electrons.com
Thu Aug 21 01:37:06 PDT 2014

Hi Ludovic,

On Thu, 21 Aug 2014 10:16:19 +0200
Ludovic Desroches <ludovic.desroches at atmel.com> wrote:

> Hi Boris,
> You can add
> Tested-by: Ludovic Desroches <ludovic.desroches at atmel.com>

Thanks for testing this driver.

> Only one issue but not related to your patches, you can't display
> quickly the bootup logo since the panel detection takes too much
> time.

Yes, actually this is related to the device probe order: the
hlcdc-display-controller device is probed before the simple-panel, thus
nothing is detected on the RGB connector (I use of_drm_find_panel to
check for panel availability) when the display controller is
instantiated. I rely on the default polling infrastructure provided by
the DRM/KMS framework which polls for a new connector every 10s, and
this is far more than you kernel boot time.

Do anyone see a solution to reduce this delay (without changing the
polling interval). I thought we could add a notifier infrastructure to
the DRM panel framework, but I'm not sure this is how you want things

Best Regards,


Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering

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