[U-Boot] [PATCH 1/2] i.MX: mxc_ipuv3_fb: add ipuv3_fb_shutdown() routine to stop IPU before bootm

Stefano Babic
2012-09-23T15:56:42Z

On 22/09/2012 16:37, Fabio Estevam wrote:
> On Sat, Sep 22, 2012 at 10:42 AM, Otavio Salvador
> <otavio@ossystems.com.br> wrote:
>> Hello Eric,
>>
>> On Fri, Sep 21, 2012 at 5:36 PM, Eric Nelson
>> <eric.nelson@boundarydevices.com> wrote:
>>> Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
>>
>> Did you test it in mx5 too? We seem to need to handle it in mx5 too as
>> we had hungs in FSL kernel when using framebuffer in U-Boot. We're
>> using a patch in kernel for workaround it but it seems your fix does
>> what is need.
>
> I have just tested Eric's series on a mx53loco and it does fix the
> kernel hang issue.
>
> I made some comments on this series and hopefully Eric's v2 can get
> into 2012.10, since this is a bug fix.

Ok, I am waiting for V2 and I will push it.

Anyway, a question about the issue. It seems to me that it is not
possible with IPUV3 (I have not tested myself, so my question) to get
the u-boot splashscreen displayed on the LCD until the kernel has
finished to boot. This could be possible (and it is possible on other
SOC) if the IPU is loaded as module instead of statically linked to the
kernel, and if the kernel does not touch the IPU setup. This means also
that it should not disable the clocks used by U-Boot for the IPU.

But I understand from your patch that this way is not possible on
iMX53/MX6, and IPU must be always disabled. Is this correct ?

Best regards,
Stefano

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