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Subjectdrivers/mmc/card/block.c infinite loop in mmc_blk_err_check waiting on R1_READY_FOR_DATA
In the 3.7-rc3 kernel, there is an infinite loop in the 
mmc_blk_err_check() function in drivers/mmc/card/block.c that can be
caused bad hardware. This loop has moved around a little, but appears to
have been around in the kernel since v2.6.12. The code will loop
forever on write if the card isn't ready for data or if it's in program
mode. I did some searching and saw that it was reported to
linux-mmc@vger.kernel.org
http://permalink.gmane.org/gmane.linux.kernel.mmc/2021 back in May but
didn't see a response. Should there be a maximum retry count or a
timeout to prevent an infinite loop?


1030 /*
1031 * Everything else is either success, or a data error of some
1032 * kind. If it was a write, we may have transitioned to
1033 * program mode, which we have to wait for it to complete.
1034 */
1035 if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
1036 u32 status;
1037 do {
1038 int err = get_card_status(card, &status, 5);
1039 if (err) {
1040
pr_err("%s: error %d requesting status\n",
1041 req->rq_disk->disk_name, err);
1042 return MMC_BLK_CMD_ERR;
1043 }
1044 /*
1045 * Some cards mishandle the status bits,
1046 * so make sure to check both the busy
1047 * indication and the card state.
1048 */
1049 } while (!(status & R1_READY_FOR_DATA) ||
1050 (R1_CURRENT_STATE(status) == R1_STATE_PRG));
1051 }



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