aspeed/smc: handle dummies only in fast read mode

HW works fine in normal read mode with dummy bytes being set. So let's
check this case to not transfer bytes.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-id: 1486648058-520-4-git-send-email-clg@kaod.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/hw/ssi/aspeed_smc.c b/hw/ssi/aspeed_smc.c
index 087b29e8da1020f9d61619f5a0fac1650124b913..70177078a8f2c2d81c79eab9bc2ca6b283640dea 100644 (file)
--- a/hw/ssi/aspeed_smc.c
+++ b/hw/ssi/aspeed_smc.c
@@ -536,10 +536,13 @@ static uint64_t aspeed_smc_flash_read(void *opaque, hwaddr addr, unsigned size)
         /*
          * Use fake transfers to model dummy bytes. The value should
          * be configured to some non-zero value in fast read mode and
-         * zero in read mode.
+         * zero in read mode. But, as the HW allows inconsistent
+         * settings, let's check for fast read mode.
          */
-        for (i = 0; i < aspeed_smc_flash_dummies(fl); i++) {
-            ssi_transfer(fl->controller->spi, 0xFF);
+        if (aspeed_smc_flash_mode(fl) == CTRL_FREADMODE) {
+            for (i = 0; i < aspeed_smc_flash_dummies(fl); i++) {
+                ssi_transfer(fl->controller->spi, 0xFF);
+            }
         }
 
         for (i = 0; i < size; i++) {