mtd: spi-nor: ignore errors in spi_nor_unlock_all() (bdb1a75e) · Commits · 戴 / test

Just try to unlock the whole SPI-NOR flash array. Don't abort the probing in case of an error. Justifications: (1) For some boards, this just works because spi_nor_write_16bit_sr_and_check() is broken and just checks the second half of the 16bit. Once that will be fixed, SPI probe will fail for boards which has hardware-write protected SPI-NOR flashes. (2) Until now, hardware write-protection was the only viable solution to use the block protection bits. This is because this very function spi_nor_unlock_all() will be called unconditionally on every linux boot. Therefore, this bits only makes sense in combination with the hardware write-protection. If we would fail the SPI probe on an error in spi_nor_unlock_all() we'd break virtually all users of the block protection bits. (3) We should try hard to keep the MTD working even if the flash might not be writable/erasable. Fixes: ("mtd: spi-nor: Rework the disabling of block write protection") Signed-off-by:

Michael Walle <michael@walle.cc> Signed-off-by:

Vignesh Raghavendra <vigneshr@ti.com> Reviewed-by:

Tudor Ambarus <tudor.ambarus@microchip.com> Link: https://lore.kernel.org/r/20201203162959.29589-3-michael@walle.cc

drivers/mtd/spi-nor/core.c

+13 −10

Original line number	Diff line number	Diff line
		@@ -3122,20 +3122,27 @@ static int spi_nor_quad_enable(struct spi_nor *nor)
		}

		/**
		* spi_nor_unlock_all() - Unlocks the entire flash memory array.
		* spi_nor_try_unlock_all() - Tries to unlock the entire flash memory array.
		* @nor: pointer to a 'struct spi_nor'.
		*
		* Some SPI NOR flashes are write protected by default after a power-on reset
		* cycle, in order to avoid inadvertent writes during power-up. Backward
		* compatibility imposes to unlock the entire flash memory array at power-up
		* by default.
		*
		* Unprotecting the entire flash array will fail for boards which are hardware
		* write-protected. Thus any errors are ignored.
		*/
		static int spi_nor_unlock_all(struct spi_nor *nor)
		static void spi_nor_try_unlock_all(struct spi_nor *nor)
		{
		if (nor->flags & SNOR_F_HAS_LOCK)
		return spi_nor_unlock(&nor->mtd, 0, nor->params->size);
		int ret;

		return 0;
		if (!(nor->flags & SNOR_F_HAS_LOCK))
		return;

		ret = spi_nor_unlock(&nor->mtd, 0, nor->params->size);
		if (ret)
		dev_dbg(nor->dev, "Failed to unlock the entire flash memory array\n");
		}

		static int spi_nor_init(struct spi_nor *nor)
		@@ -3154,11 +3161,7 @@ static int spi_nor_init(struct spi_nor *nor)
		return err;
		}

		err = spi_nor_unlock_all(nor);
		if (err) {
		dev_dbg(nor->dev, "Failed to unlock the entire flash memory array\n");
		return err;
		}
		spi_nor_try_unlock_all(nor);

		if (nor->addr_width == 4 &&
		nor->read_proto != SNOR_PROTO_8_8_8_DTR &&

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