[RFC PATCH v3 2/2] clk: exynos5420: Make sure MDMA0 clock is enabled during suspend

Abhilash Kesavan kesavan.abhilash at gmail.com
Tue Mar 31 20:19:14 PDT 2015


Hi Kevin,

On Wed, Apr 1, 2015 at 2:32 AM, Kevin Hilman <khilman at kernel.org> wrote:
> Javier Martinez Canillas <javier.martinez at collabora.co.uk> writes:
>
> [...]
>
>> Unfortunately I don't fully understand why this clock needs to be
>> enabled. It would be good if someone at Samsung can explain in more
>> detail what the real problem really is.
>
> +1
>
> Maybe Abhilash can shed some light here?
>
> We really should know *why* this is needed because having the fix in the
> clock driver just doesn't seem right.  It seems like the DMA driver
> should be managing this clock.

I think my last mail might not have reached you (was accidentally sent
as html). We are gating the aclk266_g2d clock without checking the
CG_STATUS0 register bits as specified in the UM. It looks like we need
to keep several clocks alive or gate them only after checking the
CG_STATUSx register bits.

Regards,
Abhilash



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