Re: [PATCH] mmc: core: Ensure clocks are always enabled before host interaction

[Sujit Reddy Thumma <sthumma@codeaurora.org>]

Hi Linus Walleij,

On 12/30/2011 7:44 AM, Linus Walleij wrote:
> On Mon, Dec 12, 2011 at 9:21 AM, Sujit Reddy Thumma
> <sthumma@codeaurora.org>  wrote:
>
>> Ensure clocks are always enabled before any interaction with the
>> host controller driver. This makes sure that there is no race
>> between host execution and the core layer turning off clocks
>> in different context with clock gating framework.
>>
>> Signed-off-by: Sujit Reddy Thumma<sthumma@codeaurora.org>
>
> I guess Per Förlin may not be available, but would have preferred to
> have his view on this as well, since he knows the semantics of
> pre/post-req.

I have checked the implementation for pre-req and post-req in mmc host 
drivers. There is no interaction to the controller or card registers in 
these functions, but in future if drivers appeal to configure their 
controller in these functions then we must have clocks enabled.

Per, if you are available can you comment on this?

>
> However from my PoV it looks nice and clean, and you surely have
> done some serious testing on things like SDIO so:
> Acked-by: Linus Walleij<linus.walleij@linaro.org>

Thanks. Tested with SD3.0, eMMC4.4 and SDIO2.0 cards.


Thanks,
Sujit