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| author | Trey Ramsay <tramsay@linux.vnet.ibm.com> | 2012-11-16 09:31:41 -0600 |
|---|---|---|
| committer | Chris Ball <cjb@laptop.org> | 2012-12-06 13:54:42 -0500 |
| commit | 8fee476b219d1869762d9ef5c189a0c85e919a4d (patch) | |
| tree | 460bb7932c106fae3b84646117b82e79c2618110 /drivers/mmc/core/mmc_ops.c | |
| parent | e95baf132f9709b86721a562210403473ef72249 (diff) | |
| download | linux-8fee476b219d1869762d9ef5c189a0c85e919a4d.tar.gz linux-8fee476b219d1869762d9ef5c189a0c85e919a4d.tar.bz2 linux-8fee476b219d1869762d9ef5c189a0c85e919a4d.zip | |
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 <tramsay@linux.vnet.ibm.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/core/mmc_ops.c')
| -rw-r--r-- | drivers/mmc/core/mmc_ops.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c index a0e172042e65..6d8f7012d73a 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)) { |