Unverified Commit b0e2d252 authored Mar 23, 2020 by Tudor Ambarus

mtd: spi-nor: Set all BP bits to one when lock_len == mtd->size



When there are more BP settings than needed for defining the protected
areas of the flash memory, most flashes will define the remaining
settings as "protect all", i.e. the equivalent of having all the BP bits
set to one. But there are flashes where the in-between BP values
are undefined (not mentioned), and only the "all bits set" is protecting
the entire memory. One such example is w25q80, where BP[2:0]=0b101 and
0b110 are not defined.

Set all the BP bits to one when lock_len == mtd->size, to treat this
special case.

Suggested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Reviewed-by: Jungseung Lee <js07.lee@samsung.com>
Reviewed-by: Michael Walle <michael@walle.cc>

parent 5bb783cc

drivers/mtd/spi-nor/core.c

+13 −7

Original line number	Original line	Diff line number	Diff line
	@@ -1682,13 +1682,19 @@ static int spi_nor_sr_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
	*		*
	* pow = ceil(log2(size / len)) = log2(size) - floor(log2(len))		* pow = ceil(log2(size / len)) = log2(size) - floor(log2(len))
	*/		*/
			if (lock_len == mtd->size) {
			val = mask;
			} else {
	pow = ilog2(mtd->size) - ilog2(lock_len);		pow = ilog2(mtd->size) - ilog2(lock_len);
	val = mask - (pow << SR_BP_SHIFT);		val = mask - (pow << SR_BP_SHIFT);

	if (val & ~mask)		if (val & ~mask)
	return -EINVAL;		return -EINVAL;

	/* Don't "lock" with no region! */		/* Don't "lock" with no region! */
	if (!(val & mask))		if (!(val & mask))
	return -EINVAL;		return -EINVAL;
			}

	status_new = (status_old & ~mask & ~tb_mask) \| val;		status_new = (status_old & ~mask & ~tb_mask) \| val;

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