mmc: core: Add option to prevent eMMC sleep command

Host may now use MMC_CAP2_NO_SLEEP_CMD to disable the use
of eMMC sleep/awake command.

This option can be used when your platform has a buggy
kernel crash dump software, which is supposed to store
the dump on the eMMC, but is not able to wake up the eMMC
from sleep state.

In particular, failures have been seen with u-boot; even if
it is fixed there, platforms will be slow to update their
bootloader binaries.

Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Reviewed-by: Hanumath Prasad <hanumath.prasad@stericsson.com>
Reviewed-by: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 22050525be84910733802a70543b309b26e3906d..be7569f3fb5636425a64835cdca029a4c500f593 100644 (file)
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2246,6 +2246,9 @@ int mmc_card_awake(struct mmc_host *host)
 {
        int err = -ENOSYS;
 
+       if (host->caps2 & MMC_CAP2_NO_SLEEP_CMD)
+               return 0;
+
        mmc_bus_get(host);
 
        if (host->bus_ops && !host->bus_dead && host->bus_ops->awake)
@@ -2261,6 +2264,9 @@ int mmc_card_sleep(struct mmc_host *host)
 {
        int err = -ENOSYS;
 
+       if (host->caps2 & MMC_CAP2_NO_SLEEP_CMD)
+               return 0;
+
        mmc_bus_get(host);
 
        if (host->bus_ops && !host->bus_dead && host->bus_ops->sleep)

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 742f0e102e1e88a2a89b7e37449b51839e90362c..031d865167a27b73a747f932a1378fe7b3535069 100644 (file)
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -247,6 +247,7 @@ struct mmc_host {
 #define MMC_CAP2_CACHE_CTRL    (1 << 1)        /* Allow cache control */
 #define MMC_CAP2_POWEROFF_NOTIFY (1 << 2)      /* Notify poweroff supported */
 #define MMC_CAP2_NO_MULTI_READ (1 << 3)        /* Multiblock reads don't work */
+#define MMC_CAP2_NO_SLEEP_CMD  (1 << 4)        /* Don't allow sleep command */
 
        mmc_pm_flag_t           pm_caps;        /* supported pm features */
        unsigned int        power_notify_type;