On 30 September 2015 at 14:01, Adrian Hunter [off-list ref] wrote:

On 30/09/15 12:37, Chaotian Jing wrote:

quoted

When get a CRC error, start the mmc_retune, it will issue CMD19/CMD21
to do tune, assume there were 10 clock phase need to try, phase 0 to
phase 6 is ok, phase 7 to phase 9 is NG, we try it from 0 to 9, so
the last CMD19/CMD21 will get CRC error, host->need_retune was set and
cause mmc_retune was called, then dead loop of mmc_retune

Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>

Wasn't my idea to have this CRC checking in the core ;-) and sdhci
doesn't put it's tuning commands through a mmc request so it doesn't
see this issue.

That's not true for all sdhci variants. For those that uses sdhci's
->platform_execute_tuning() callback, all uses mmc_send_tuning().

I think for sdhci's default tuning path, we should change to use
mmc_send_tuning() and thus we would potentially hit this problem as
well.

But definitely the CRC logic is not meant for the tuning commands, so

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

Thanks for reviewing Adrian and for keeping an eye on "tuning" related patches.

Kind regards
Uffe