[PATCH v2 mvebu + mvebu/dt64 1/6] firmware: turris-mox-rwtm: fix reply status decoding function

[Pali Rohár]

From: Marek Behún <kabel at kernel.org>

The status decoding function mox_get_status() currently contains a dead
code path: if the error status is not MBOX_STS_SUCCESS, it always
returns -EIO, so the comparison to MBOX_STS_FAIL is never executed and
we don't get the actual error code sent by the firmware.

Fix this.

Signed-off-by: Marek Behún <kabel at kernel.org>
Fixes: 389711b37493 ("firmware: Add Turris Mox rWTM firmware driver")
---
 drivers/firmware/turris-mox-rwtm.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/turris-mox-rwtm.c b/drivers/firmware/turris-mox-rwtm.c
index 62f0d1a5dd32..f85acdb3130c 100644
--- a/drivers/firmware/turris-mox-rwtm.c
+++ b/drivers/firmware/turris-mox-rwtm.c
@@ -147,11 +147,14 @@ MOX_ATTR_RO(pubkey, "%s\n", pubkey);
 
 static int mox_get_status(enum mbox_cmd cmd, u32 retval)
 {
-	if (MBOX_STS_CMD(retval) != cmd ||
-	    MBOX_STS_ERROR(retval) != MBOX_STS_SUCCESS)
+	if (MBOX_STS_CMD(retval) != cmd)
 		return -EIO;
 	else if (MBOX_STS_ERROR(retval) == MBOX_STS_FAIL)
 		return -(int)MBOX_STS_VALUE(retval);
+	else if (MBOX_STS_ERROR(retval) == MBOX_STS_BADCMD)
+		return -ENOSYS;
+	else if (MBOX_STS_ERROR(retval) != MBOX_STS_SUCCESS)
+		return -EIO;
 	else
 		return MBOX_STS_VALUE(retval);
 }
-- 
2.20.1