Commit 4ab1fcc7 authored Nov 08, 2017 by Miquel Raynal Committed by Greg Kroah-Hartman Mar 19, 2018

mtd: nand: fix interpretation of NAND_CMD_NONE in nand_command[_lp]()




[ 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@free-electrons.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent bd174cd1

drivers/mtd/nand/nand_base.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -710,6 +710,7 @@ static void nand_command(struct mtd_info *mtd, unsigned int command,
		chip->cmd_ctrl(mtd, readcmd, ctrl);
		ctrl &= ~NAND_CTRL_CHANGE;
		}
		if (command != NAND_CMD_NONE)
		chip->cmd_ctrl(mtd, command, ctrl);

		/* Address cycle, when necessary */
		@@ -739,6 +740,7 @@ 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:
		@@ -832,7 +834,9 @@ 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;
		@@ -868,6 +872,7 @@ 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: