[PATCH v3 2/4] mtd: rawnand: Fix nand_choose_best_timings() on unsupported interface

From: Herve Codina
Date: Fri Nov 19 2021 - 10:03:31 EST


When the NV-DDR interface is not supported by the NAND chip,
the value of onfi->nvddr_timing_modes is 0. In this case,
the best_mode variable value in nand_choose_best_nvddr_timings()
is -1. The last for-loop is skipped and the function returns an
uninitialized value.
If this returned value is 0, the nand_choose_best_sdr_timings()
is not executed and no 'best timing' are set. This leads the host
controller and the NAND chip working at default mode 0 timing
even if a better timing can be used.

Fix this uninitialized returned value.

nand_choose_best_sdr_timings() is pretty similar to
nand_choose_best_nvddr_timings(). Even if onfi->sdr_timing_modes
should never be seen as 0, nand_choose_best_sdr_timings() returned
value is fixed.

Fixes: a9ecc8c814e9 ("mtd: rawnand: Choose the best timings, NV-DDR included")
Signed-off-by: Herve Codina <herve.codina@xxxxxxxxxxx>
---
Changes v1 to v2:
- New patch in v2 series

Changes v2 -> v3:
- Fix commit log typo

drivers/mtd/nand/raw/nand_base.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 5c6b065837ef..a130320de412 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -926,7 +926,7 @@ int nand_choose_best_sdr_timings(struct nand_chip *chip,
struct nand_sdr_timings *spec_timings)
{
const struct nand_controller_ops *ops = chip->controller->ops;
- int best_mode = 0, mode, ret;
+ int best_mode = 0, mode, ret = -EOPNOTSUPP;

iface->type = NAND_SDR_IFACE;

@@ -977,7 +977,7 @@ int nand_choose_best_nvddr_timings(struct nand_chip *chip,
struct nand_nvddr_timings *spec_timings)
{
const struct nand_controller_ops *ops = chip->controller->ops;
- int best_mode = 0, mode, ret;
+ int best_mode = 0, mode, ret = -EOPNOTSUPP;

iface->type = NAND_NVDDR_IFACE;

--
2.31.1