Re: 答复: SDHC driver of RTEMS

ruizx ruizx at qq.com
Tue Aug 6 01:34:51 UTC 2013


Sebastian Huber wrote:
> On 2013-08-05 12:51, 芮正新 wrote:
>> Thanks for your reply.
>> Can you give me some advices to resolve my problems?
> 
> I would look at the latest errata documents from Freescale and the
> Linux driver. 
> 
> I would also test the driver without a file system.  Just use the
> bdbuf (or event the driver IO control) directly.  Example:
> 
> http://git.rtems.org/rtems/tree/testsuites/libtests/block16/init.c

This example do not define CONFIGURE_BDBUF_MAX_READ_AHEAD_BLOCKS, so BRDA task could not start.
I found that if defined CONFIGURE_BDBUF_MAX_READ_AHEAD_BLOCKS, the problem appeared, 
and if not define the macro, there was no problem, but the multi-block command never used, just single block read.
Single block access has slow speed and efficiency.

PS:
Sorry for my bad maillist tool, it took some Chinese characters to mails previous. 
I've corrected it and changed my maillist account to the new one.


Best Regards,
Rui Zhengxin




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