This is a note to let you know that I've just added the patch titled mtd: rawnand: Fix nand_choose_best_timings() on unsupported interface to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mtd-rawnand-fix-nand_choose_best_timings-on-unsuppor.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 18ebdf4af3a945217a0e5a84b07a1dadc378f4b5 Author: Herve Codina <herve.codina@xxxxxxxxxxx> Date: Fri Nov 19 16:03:14 2021 +0100 mtd: rawnand: Fix nand_choose_best_timings() on unsupported interface [ Upstream commit 36a65982a98c4bc72fdcfef2c4aaf90193746631 ] 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> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx> Link: https://lore.kernel.org/linux-mtd/20211119150316.43080-3-herve.codina@xxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c index 5c6b065837eff..a130320de4128 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;