ARM: 5896/1: MMCI: work around a hardware bug in U300

In the U300 some hardware bug makes the status flag not come up
signalling a successful write (or anything else, like an error, for
that matter) on write requests. This little quirk makes the writes
work on U300.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 90d168ad03b6..643818a5ac45 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -184,6 +184,17 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data,
 {
         if (status & MCI_DATABLOCKEND) {
                 host->data_xfered += data->blksz;
+#ifdef CONFIG_ARCH_U300
+                /*
+                 * On the U300 some signal or other is
+                 * badly routed so that a data write does
+                 * not properly terminate with a MCI_DATAEND
+                 * status flag. This quirk will make writes
+                 * work again.
+                 */
+                if (data->flags & MMC_DATA_WRITE)
+                        status |= MCI_DATAEND;
+#endif
         }
         if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
                 if (status & MCI_DATACRCFAIL)