From: Miquel Raynal <miquel.raynal@xxxxxxxxxxxxxxxxxx> [ Upstream commit df467899da0b71465760b4e35127bce837244eee ] Some drivers (like nand_hynix.c) call ->cmdfunc() with NAND_CMD_NONE and a column address and expect the controller to only send address cycles. Right now, the default ->cmdfunc() implementations provided by the core do not filter out the command cycle in this case and forwards the request to the controller driver through the ->cmd_ctrl() method. The thing is, NAND controller drivers can get this wrong and send a command cycle with a NAND_CMD_NONE opcode and since NAND_CMD_NONE is -1, and the command field is usually casted to an u8, we end up sending the 0xFF command which is actually a RESET operation. Add conditions in nand_command[_lp]() functions to sending the initial command cycle when command == NAND_CMD_NONE. Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxxxxxxxxx> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- drivers/mtd/nand/nand_base.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 7eddb1e95de3..c8f20467ff1d 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -600,7 +600,8 @@ static void nand_command(struct mtd_info *mtd, unsigned int command, chip->cmd_ctrl(mtd, readcmd, ctrl); ctrl &= ~NAND_CTRL_CHANGE; } - chip->cmd_ctrl(mtd, command, ctrl); + if (command != NAND_CMD_NONE) + chip->cmd_ctrl(mtd, command, ctrl); /* Address cycle, when necessary */ ctrl = NAND_CTRL_ALE | NAND_CTRL_CHANGE; @@ -629,6 +630,7 @@ static void nand_command(struct mtd_info *mtd, unsigned int command, */ switch (command) { + case NAND_CMD_NONE: case NAND_CMD_PAGEPROG: case NAND_CMD_ERASE1: case NAND_CMD_ERASE2: @@ -691,7 +693,9 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command, } /* Command latch cycle */ - chip->cmd_ctrl(mtd, command, NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE); + if (command != NAND_CMD_NONE) + chip->cmd_ctrl(mtd, command, + NAND_NCE | NAND_CLE | NAND_CTRL_CHANGE); if (column != -1 || page_addr != -1) { int ctrl = NAND_CTRL_CHANGE | NAND_NCE | NAND_ALE; @@ -724,6 +728,7 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command, */ switch (command) { + case NAND_CMD_NONE: case NAND_CMD_CACHEDPROG: case NAND_CMD_PAGEPROG: case NAND_CMD_ERASE1: -- 2.14.1