[Qemu-devel] [PATCH 06/20] sdcard: Add a "validate-crc" property

[Philippe Mathieu-Daudé]

Since not all modelled controllers use the CRC verification (which is
somehow expensive), let the controller have a configurable property
to enable verification.

So far only the Milkymist controller uses it.

This silent the Coverity warning:

  "Code block is unreachable because of the syntactic structure of the code 
(CWE-561)"

and fixes the following issue:

- CID1005332 (hw/sd/sd.c::sd_req_crc_validate) Structurally dead code

Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
 hw/sd/milkymist-memcard.c |  1 +
 hw/sd/sd.c                | 12 ++++++++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/hw/sd/milkymist-memcard.c b/hw/sd/milkymist-memcard.c
index d8cbb7b681..04babc092f 100644
--- a/hw/sd/milkymist-memcard.c
+++ b/hw/sd/milkymist-memcard.c
@@ -278,6 +278,7 @@ static void milkymist_memcard_realize(DeviceState *dev, 
Error **errp)
     blk = dinfo ? blk_by_legacy_dinfo(dinfo) : NULL;
     carddev = qdev_create(&s->sdbus.qbus, TYPE_SD_CARD);
     qdev_prop_set_drive(carddev, "drive", blk, &err);
+    object_property_set_bool(OBJECT(carddev), true, "validate-crc", &err);
     object_property_set_bool(OBJECT(carddev), true, "realized", &err);
     if (err) {
         error_setg(errp, "failed to init SD card: %s", error_get_pretty(err));
diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index be75e118c0..801ddc2cb5 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -93,6 +93,7 @@ struct SDState {
     /* Configurable properties */
     BlockBackend *blk;
     bool spi;
+    bool validate_crc;
 
     uint32_t mode;    /* current card mode, one of SDCardModes */
     int32_t state;    /* current card state, one of SDCardStates */
@@ -496,10 +497,12 @@ static bool sd_verify_frame48_checksum(SDFrame48 *frame)
     return crc == frame->crc;
 }
 
-static int sd_req_crc_validate(SDRequest *req)
+static bool sd_req_crc_validate(SDState *sd, SDRequest *req)
 {
-    return 0;
-    return !sd_verify_frame48_checksum(req); /* TODO */
+    if (sd->validate_crc) {
+        return sd_verify_frame48_checksum(req);
+    }
+    return true;
 }
 
 static void sd_update_frame48_checksum(SDFrame48 *frame)
@@ -1685,7 +1688,7 @@ int sd_do_command(SDState *sd, SDRequest *req,
         return 0;
     }
 
-    if (sd_req_crc_validate(req)) {
+    if (!sd_req_crc_validate(sd, req)) {
         sd->card_status |= COM_CRC_ERROR;
         rtype = sd_illegal;
         goto send_response;
@@ -2134,6 +2137,7 @@ static Property sd_properties[] = {
      * board to ensure that ssi transfers only occur when the chip select
      * is asserted.  */
     DEFINE_PROP_BOOL("spi", SDState, spi, false),
+    DEFINE_PROP_BOOL("validate-crc", SDState, validate_crc, false),
     DEFINE_PROP_END_OF_LIST()
 };
 
-- 
2.17.0