mmc: sdhci: Fix CMD line reset interfering with ongoing data transfer

commit 6ebebeab5185f50d55c6a24d0abe47e5dac1b191 upstream.

CMD line reset during an ongoing data transfer can cause the data transfer
to hang.  Fix by delaying the reset until the data transfer is finished.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a8a022a7358ff1405bf636542044565a67af025f..6bb83ea85c7f3813487599c7518c6da03d97b98c 100644 (file)
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -2269,10 +2269,8 @@ static bool sdhci_request_done(struct sdhci_host *host)
 
        for (i = 0; i < SDHCI_MAX_MRQS; i++) {
                mrq = host->mrqs_done[i];
-               if (mrq) {
-                       host->mrqs_done[i] = NULL;
+               if (mrq)
                        break;
-               }
        }
 
        if (!mrq) {
@@ -2303,6 +2301,17 @@ static bool sdhci_request_done(struct sdhci_host *host)
         * upon error conditions.
         */
        if (sdhci_needs_reset(host, mrq)) {
+               /*
+                * Do not finish until command and data lines are available for
+                * reset. Note there can only be one other mrq, so it cannot
+                * also be in mrqs_done, otherwise host->cmd and host->data_cmd
+                * would both be null.
+                */
+               if (host->cmd || host->data_cmd) {
+                       spin_unlock_irqrestore(&host->lock, flags);
+                       return true;
+               }
+
                /* Some controllers need this kick or reset won't work here */
                if (host->quirks & SDHCI_QUIRK_CLOCK_BEFORE_RESET)
                        /* This is to force an update */
@@ -2310,10 +2319,8 @@ static bool sdhci_request_done(struct sdhci_host *host)
 
                /* Spec says we should do both at the same time, but Ricoh
                   controllers do not like that. */
-               if (!host->cmd)
-                       sdhci_do_reset(host, SDHCI_RESET_CMD);
-               if (!host->data_cmd)
-                       sdhci_do_reset(host, SDHCI_RESET_DATA);
+               sdhci_do_reset(host, SDHCI_RESET_CMD);
+               sdhci_do_reset(host, SDHCI_RESET_DATA);
 
                host->pending_reset = false;
        }
@@ -2321,6 +2328,8 @@ static bool sdhci_request_done(struct sdhci_host *host)
        if (!sdhci_has_requests(host))
                sdhci_led_deactivate(host);
 
+       host->mrqs_done[i] = NULL;
+
        mmiowb();
        spin_unlock_irqrestore(&host->lock, flags);