From 8fee476b219d1869762d9ef5c189a0c85e919a4d Mon Sep 17 00:00:00 2001 From: Trey Ramsay Date: Fri, 16 Nov 2012 09:31:41 -0600 Subject: mmc: core: Fix some driver hangs when dealing with broken devices There are infinite loops in the mmc code that can be caused by bad hardware. The code will loop forever if the device never comes back from program mode, R1_STATE_PRG, and it is not ready for data, R1_READY_FOR_DATA. A long timeout is added to prevent the code from looping forever. The timeout will occur if the device never comes back from program state or the device never becomes ready for data. It's not clear whether the timeout will do more than log a pr_err() and then start a fresh hang all over again. We may need to extend this patch later to perform some kind of reset of the device (is that possible?) or rejection of new I/O to the device. Signed-off-by: Trey Ramsay Signed-off-by: Chris Ball --- drivers/mmc/core/mmc_ops.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'drivers/mmc/core/mmc_ops.c') diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c index a0e172042e6..6d8f7012d73 100644 --- a/drivers/mmc/core/mmc_ops.c +++ b/drivers/mmc/core/mmc_ops.c @@ -21,6 +21,8 @@ #include "core.h" #include "mmc_ops.h" +#define MMC_OPS_TIMEOUT_MS (10 * 60 * 1000) /* 10 minute timeout */ + static int _mmc_select_card(struct mmc_host *host, struct mmc_card *card) { int err; @@ -409,6 +411,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, { int err; struct mmc_command cmd = {0}; + unsigned long timeout; u32 status; BUG_ON(!card); @@ -437,6 +440,7 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, return 0; /* Must check status to be sure of no errors */ + timeout = jiffies + msecs_to_jiffies(MMC_OPS_TIMEOUT_MS); do { err = mmc_send_status(card, &status); if (err) @@ -445,6 +449,13 @@ int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value, break; if (mmc_host_is_spi(card->host)) break; + + /* Timeout if the device never leaves the program state. */ + if (time_after(jiffies, timeout)) { + pr_err("%s: Card stuck in programming state! %s\n", + mmc_hostname(card->host), __func__); + return -ETIMEDOUT; + } } while (R1_CURRENT_STATE(status) == R1_STATE_PRG); if (mmc_host_is_spi(card->host)) { -- cgit v1.2.3-70-g09d2