Re: [PATCH 19/20] OMAPDSS: DSI: fix DSI channel source initialization

[Tomi Valkeinen <tomi.valkeinen@ti.com>]

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On 2013-03-11 08:10, Archit Taneja wrote:
> Hi,
> 
> On Friday 08 March 2013 05:21 PM, Tomi Valkeinen wrote:
>> During the initialization of the DSI protocol registers, we always set
>> the sources of all DSI channels to L4. However, we don't update the
>> value in the dsi_data, so we may end up with a different value in the
>> register and in the dsi_data, leading to DSI problems.
>>
>> This patch fixes the issue by initializing also the channel source in
>> the dsi_data.
> 
> We set in omap_dsihw_probe:
> 
> static int __init omap_dsihw_probe(struct platform_device *dsidev)
> {
>     ...
>     ...
>         /* DSI VCs initialization */
>         for (i = 0; i < ARRAY_SIZE(dsi->vc); i++) {
>                 dsi->vc[i].source = DSI_VC_SOURCE_L4;
>                 dsi->vc[i].dssdev = NULL;
>                 dsi->vc[i].vc_id = 0;
>         }
>     ...
>     ...
> }

Hmm... I did have a bug related to this when prototyping CDF. Ah.
Consider this:

Panel powers up and uses DSI normally. A DSI VC is set to video mode.
Then the panel power down. Then it powers up again, and enables DSI. At
this time, dsi_vc_initial_config() is called again, setting the source
in the registers to L4. But the source in dsi_data is still VP.

So perhaps the whole piece of code from omap_dsihw_probe should be moved
to somewhere else (dsi_vc_initial_config() sounds like a good place), so
that they are initialized each time the registers are initialized.

 Tomi



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