Commit 3cff177f authored by Shivamurthy Shastri's avatar Shivamurthy Shastri Committed by Miquel Raynal
Browse files

mtd: map_ram: prevent use of point and unpoint when NO_XIP is set 



When the DT property no-unaligned-direct-access is set, map->phys is set
to NO_XIP. With this property set, the flash should not be exposed
directly to MTD users, since it cannot be mapped.

map_ram() exposes the flash direct access unconditionally which leads to
access errors (when the bus width does not match the RAM width).

Therefore do not set point and unpoint when NO_XIP is set.

Signed-off-by: default avatarShivamurthy Shastri <shivamurthy.shastri@linutronix.de>
Reviewed-by: default avatarBenedikt Spranger <b.spranger@linutronix.de>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230919113320.16953-1-shivamurthy.shastri@linutronix.de
parent 28a05da7

drivers/mtd/chips/map_ram.c

+6 −2
Original line number Diff line number Diff line
@@ -70,12 +70,16 @@ static struct mtd_info *map_ram_probe(struct map_info *map) 
	mtd->_read = mapram_read;

	mtd->_write = mapram_write;

	mtd->_panic_write = mapram_write;

	mtd->_point = mapram_point;

	mtd->_sync = mapram_nop;

	mtd->_unpoint = mapram_unpoint;

	mtd->flags = MTD_CAP_RAM;

	mtd->writesize = 1;



	/* Disable direct access when NO_XIP is set */

	if (map->phys != NO_XIP) {

		mtd->_point = mapram_point;

		mtd->_unpoint = mapram_unpoint;

	}



	mtd->erasesize = PAGE_SIZE;

 	while(mtd->size & (mtd->erasesize - 1))

		mtd->erasesize >>= 1;