[PATCH][V3] net: dsa: sja1105: fix check on while loop exit

From: Colin King
Date: Wed May 08 2019 - 09:31:46 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The while-loop exit condition check is not correct; the
loop should continue if the returns from the function calls are
negative or the CRC status returns are invalid. Currently it
is ignoring the returns from the function calls. Fix this by
removing the status return checks and only break from the loop
at the very end when we know that all the success condtions have
been met.

Kudos to Dan Carpenter for describing the correct fix and
Vladimir Oltean for noting the change to the check on the number
of retries.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: 8aa9ebccae87 ("net: dsa: Introduce driver for NXP SJA1105 5-port L2 switch")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Tested-by: Vladimir Oltean <olteanv@xxxxxxxxx>
---

V2: Discard my broken origina fix. Use correct fix as described by
Dan Carpenter.
V3: Remove empty line and check for retries != RETRIES fix.
---
drivers/net/dsa/sja1105/sja1105_spi.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/sja1105/sja1105_spi.c b/drivers/net/dsa/sja1105/sja1105_spi.c
index 244a94ccfc18..49c5252a8dc6 100644
--- a/drivers/net/dsa/sja1105/sja1105_spi.c
+++ b/drivers/net/dsa/sja1105/sja1105_spi.c
@@ -466,14 +466,15 @@ int sja1105_static_config_upload(struct sja1105_private *priv)
"invalid, retrying...\n");
continue;
}
- } while (--retries && (status.crcchkl == 1 || status.crcchkg == 1 ||
- status.configs == 0 || status.ids == 1));
+ /* Success! */
+ break;
+ } while (--retries);

if (!retries) {
rc = -EIO;
dev_err(dev, "Failed to upload config to device, giving up\n");
goto out;
- } else if (retries != RETRIES - 1) {
+ } else if (retries != RETRIES) {
dev_info(dev, "Succeeded after %d tried\n", RETRIES - retries);
}

--
2.20.1