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SubjectRe: [PATCH 1/1] mmc: Some microSD cards are not recognized by PCIxx12 SDA controller
On Tue, 07 Apr 2009 01:30:28 +0200
José Marí­a Fernández González <josemariafg@gmail.com> wrote:

> It is curious. I have concentrated my tests on 2.6.29 with HZ=100 and no preemption, and I have done next tests with my microSD card and laptop:
>
> * mmc_delay(2) -> FAIL
> * mdelay(2) -> FAIL
> * mmc_delay(10) -> Works!
> * mdelay(10) -> Works!
>

Looks good. Although it would have been nice to also know exactly when
it starts working.

> And by mistake I found that:
>
> * msleep(2) -> Works!
>

This is the scheduling effect I was talking about. Basically you can
never get msleep() to delay shorter than 1/HZ seconds.

I'll queue up your patch.

Rgds
--
-- Pierre Ossman

Linux kernel, MMC maintainer http://www.kernel.org
rdesktop, core developer http://www.rdesktop.org
TigerVNC, core developer http://www.tigervnc.org

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