Re: [PATCH] [9/50] mmc: Added quirks for Ricoh 1180:e823 lower base clock

Chris Ball
2011-07-29T00:49:37Z

Hi,

On Thu, Jul 28 2011, Andi Kleen wrote:
> On Fri, Jul 29, 2011 at 09:27:56AM +0900, matsumur@nts.ricoh.co.jp wrote:
>> Dear Sir,
>>
>> Ricoh 1180:e823 device is named R5U220/R5U232 (2 devices have the same
>> device ID ).
>> So, I think it should be declared to as PCI_DEVICE_ID_RICOH_R5U220.
>
> Is that just the wrong name or will it actually cause misfunction?

I don't think it could possibly cause misfunction; it's just a macro name.

> BTW, does anyone know whether the current SDHCI-driver sets 200Mhz to
> SD-CLK for UHS-I cards ?

The Linux 3.1 SD driver will set the SD-CLK to 50MHz for every card on an
e823 device, and older kernels will do so too once the commit has been
applied to the stable trees. See this commit:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=15bed0f2fa8e1d7db201692532c210a7823d2d21

Do you know of a better solution than always lowering the clock speed to
50MHz for this controller?

Thanks,

- Chris.
--
Chris Ball <cjb@laptop.org> <http://printf.net/>
One Laptop Per Child