MMC/SD: data CRC errors and unknown SCR version on 2.6.14

From: Martin B. Andersen
Date: Mon Mar 24 2008 - 08:41:06 EST


Hi

I am having some problems with a couple of SD cards which isn't detected correctly when inserted, I have seen this with both Sandisk and Kingston cards. I am sorry to bring up issues with this old driver version, I know there has been done a lot of work after 2.6.14 with the driver.

...but the setup is this: I have backported the mmc driver from kernel 2.6.14 to 2.6.12 for my own reasons. I wasn't able to use a newer version as the driver interface had changed too much to be feasible.

When inserting a faulty card I can see, when debug output is enabled, that the communication and output is identical with a working card up until the SCR part. Here the driver reports a data CRC error but continues, and then it reports an unknown SCR version either 15 or 3, but I gather that the array with the SCR contains junk at this point so the SCR version is not to be taken seriously. Some times however it is able to succesfully detect and register the card, this is mostly seen the first time the driver is loaded, afterwards it keeps failing. Has anybody seen this behavior before? Is it timing issues or is it caused by faulty cards?

best regards
Martin
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