[Qemu-devel] [PATCH v4 1/4] sd: sdhci: mask transfer mode register value

[P J P <ppandit@redhat.com>]

From: Prasad J Pandit <pjp@fedoraproject.org>

In SDHCI protocol, the transfer mode register is defined
to be of 6 bits. Mask its value with '0x0037' so that an
invalid value could not be assigned.

Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 hw/sd/sdhci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Update per: use macro for the mask value
  -> https://lists.gnu.org/archive/html/qemu-devel/2017-02/msg02774.html

diff --git a/hw/sd/sdhci.c b/hw/sd/sdhci.c
index 5bd5ab6..cf647fa 100644
--- a/hw/sd/sdhci.c
+++ b/hw/sd/sdhci.c
@@ -119,6 +119,7 @@
     (SDHC_CAPAB_BASECLKFREQ << 8) | (SDHC_CAPAB_TOUNIT << 7) | \
     (SDHC_CAPAB_TOCLKFREQ))
 
+#define MASK_TRNMOD     0x0037
 #define MASKED_WRITE(reg, mask, val)  (reg = (reg & (mask)) | (val))
 
 static uint8_t sdhci_slotint(SDHCIState *s)
@@ -1050,7 +1051,7 @@ sdhci_write(void *opaque, hwaddr offset, uint64_t val, unsigned size)
         if (!(s->capareg & SDHC_CAN_DO_DMA)) {
             value &= ~SDHC_TRNS_DMA;
         }
-        MASKED_WRITE(s->trnmod, mask, value);
+        MASKED_WRITE(s->trnmod, mask, value & MASK_TRNMOD);
         MASKED_WRITE(s->cmdreg, mask >> 16, value >> 16);
 
         /* Writing to the upper byte of CMDREG triggers SD command generation */
-- 
2.9.3