Re: BUG: SDHCI fails to DMA-unmap, and other warnings

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Thu, Dec 17, 2015 at 10:00:45PM +0000, Russell King - ARM Linux wrote:
> And another one:
> 
> "mmcblk0: retrying because a re-tune was needed"
> 
> static int mmc_blk_err_check(struct mmc_card *card,
>                              struct mmc_async_req *areq)
> {
> ...
>         if (brq->data.error) {
>                 if (need_retune && !brq->retune_retry_done) {
>                         pr_info("%s: retrying because a re-tune was needed\n",
>                                 req->rq_disk->disk_name);
>                         brq->retune_retry_done = 1;
>                         return MMC_BLK_RETRY;
> 
> This looks like it'll spam the kernel log regularly if MMC/SD is used
> heavily with a UHS card, which (iirc) requires regular retunes.  Why is
> this message at info level, and not debug level?

And... if three problems aren't enough, have another one... running:

while :; do hdparm -t /dev/mmcblk0; done

eventually causes:

[ 3465.671526] mmc0: tuning execution failed
[ 3465.675746] mmcblk0: response CRC error sending r/w cmd command, card status 0x900
[ 3622.758988] mmc0: tuning execution failed
[ 3622.763227] mmcblk0: response CRC error sending r/w cmd command, card status 0x900
[ 3858.363555] mmc0: tuning execution failed
[ 3858.368857] mmcblk0: response CRC error sending r/w cmd command, card status 0x900
[ 3880.388048] mmc0: tuning execution failed
[ 3880.392292] mmcblk0: response CRC error sending r/w cmd command, card status 0x900

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