Re: [PATCH 1/1] mmc: Some microSD cards are not recognized byPCIxx12 SDA controller
From: Pierre Ossman
Date: Fri Apr 10 2009 - 17:36:09 EST
On Tue, 07 Apr 2009 01:30:28 +0200
Josà MarÃÂa FernÃndez GonzÃlez <josemariafg@xxxxxxxxx> 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
WARNING: This correspondence is being monitored by the
Swedish government. Make sure your server uses encryption
for SMTP traffic and consider using PGP for end-to-end
encryption.
Attachment:
signature.asc
Description: PGP signature