Unverified Commit 87aa3c8d authored by Jakub Czapiga's avatar Jakub Czapiga Committed by Mark Brown
Browse files

spi: intel: Allow writeable MTD partition with module param 



The MTD device is blocked from writing to the SPI-NOR chip if any region
of it is write-protected, even if "writeable=1" module parameter is set.

Add ability to bypass this behaviour by introducing new module parameter
"ignore_protestion_status" which allows to rely on the write protection
mechanism of SPI-NOR chip itself, which most modern chips (since
the 1990'+) have already implemented.

Any erase/write operations performed on the write-protected section will
be rejected by the chip.

Signed-off-by: default avatarJakub Czapiga <czapiga@google.com>
Link: https://patch.msgid.link/20250725122542.2633334-1-czapiga@google.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent f54b69a5

drivers/spi/spi-intel.c

+10 −3
Original line number Diff line number Diff line
@@ -189,6 +189,11 @@ struct intel_spi_mem_op { 
static bool writeable;

module_param(writeable, bool, 0);

MODULE_PARM_DESC(writeable, "Enable write access to SPI flash chip (default=0)");

static bool ignore_protection_status;

module_param(ignore_protection_status, bool, 0);

MODULE_PARM_DESC(

	ignore_protection_status,

	"Do not block SPI flash chip write access even if it is write-protected (default=0)");



static void intel_spi_dump_regs(struct intel_spi *ispi)

{
@@ -1248,13 +1253,15 @@ static void intel_spi_fill_partition(struct intel_spi *ispi, 
			continue;



		/*

		 * If any of the regions have protection bits set, make the

		 * whole partition read-only to be on the safe side.

		 * If any of the regions have protection bits set and

		 * the ignore protection status parameter is not set,

		 * make the whole partition read-only to be on the safe side.

		 *

		 * Also if the user did not ask the chip to be writeable

		 * mask the bit too.

		 */

		if (!writeable || intel_spi_is_protected(ispi, base, limit)) {

		if (!writeable || (!ignore_protection_status &&

				   intel_spi_is_protected(ispi, base, limit))) {

			part->mask_flags |= MTD_WRITEABLE;

			ispi->protected = true;

		}