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

Martin B. Andersen
2008-03-24T12:41:04Z

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