Re: Investigating SD card failures

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Pierre,

Thank your for your answer!

Pierre Ossman wrote:
> On Fri, 27 Jul 2007 07:50:26 +0200
> Manuel Lauss <[email protected]> wrote:
> 
>> Hi Pierre,
>>
>> I have a 1GB SanDisk SD card here which linux does not recognize.
>> Looking at the MMC debug output, I see the MMC core repeatedly
>> issues CMD55/CMD41 commands (which all succeed!) then stops
>> after 100 times.  In sd_ops.c the code checks for a bit to get set.
>> My question is, what exactly is this bit supposed to indicate?
>>
> 
> That the card has initialized. Try extending the time that loop runs and see if the card powers up.

Did that, waited almost 10 seconds, didn't help.  I found a printed
version of the SD spec; it turned out to be a power supply problem.
Apparently the power supply is not strong enough and/or the card
very sensitive to power fluctuations; put in another piece of hardware
with redesigned power supply the card works fine.

Sorry for the noise!

Thanks,
	Manuel Lauss
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux