sdhci: handle bug in JMB38x for sizes < 4 bytes

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 5f95e10229b5..be09739f692d 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -278,6 +278,15 @@ static void sdhci_transfer_pio(struct sdhci_host *host)
         else
                 mask = SDHCI_SPACE_AVAILABLE;
 
+        /*
+         * Some controllers (JMicron JMB38x) mess up the buffer bits
+         * for transfers < 4 bytes. As long as it is just one block,
+         * we can ignore the bits.
+         */
+        if ((host->quirks & SDHCI_QUIRK_BROKEN_SMALL_PIO) &&
+                (host->data->blocks == 1))
+                mask = ~0;
+
         while (readl(host->ioaddr + SDHCI_PRESENT_STATE) & mask) {
                 if (host->data->flags & MMC_DATA_READ)
                         sdhci_read_block_pio(host);