Hi
I have experienced problems with the MMC driver if using an bad SD card the MMC
driver ends up in an infinite loop in file block.c function mmc_blk_issue_rq.
if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
do {
int err;
cmd.opcode = MMC_SEND_STATUS;
cmd.arg = card->rca << 16;
cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
err = mmc_wait_for_cmd(card->host, &cmd, 5);
if (err) {
printk(KERN_ERR "%s: error %d requesting status\n",
req->rq_disk->disk_name, err);
goto cmd_err;
}
/*
* Some cards mishandle the status bits,
* so make sure to check both the busy
* indication and the card state.
*/
} while (!(cmd.resp[0] & R1_READY_FOR_DATA) ||
(R1_CURRENT_STATE(cmd.resp[0]) == 7));
The problem is that R1_CURRENT_STATE(cmd.resp[0]) == 7 will always be TRUE.
This problem will drain the battery on portabel devices.
The card works fine on other devices.
My idea to solve this problem is to break this loop by an timer if it take too
long time for the SD-Card to replay. Will that solution break anything? Any
other better solutions?
BR
Lekan
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