From: Michael Walle <michael@walle.cc>
To: linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: Miquel Raynal <miquel.raynal@bootlin.com>,
Richard Weinberger <richard@nod.at>,
Vignesh Raghavendra <vigneshr@ti.com>,
Tudor Ambarus <tudor.ambarus@microchip.com>,
Boris Brezillon <boris.brezillon@collabora.com>,
Michael Walle <michael@walle.cc>
Subject: [PATCH v7 2/7] mtd: spi-nor: ignore errors in spi_nor_unlock_all()
Date: Thu, 3 Dec 2020 00:00:35 +0100 [thread overview]
Message-ID: <20201202230040.14009-3-michael@walle.cc> (raw)
In-Reply-To: <20201202230040.14009-1-michael@walle.cc>
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: 3e0930f109e7 ("mtd: spi-nor: Rework the disabling of block write protection")
Signed-off-by: Michael Walle <michael@walle.cc>
---
changes since v6:
- new patch
drivers/mtd/spi-nor/core.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 5bee7c8da4dc..013198abe929 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -3121,20 +3121,27 @@ 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)
@@ -3153,11 +3160,7 @@ 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 &&
--
2.20.1
next prev parent reply other threads:[~2020-12-02 23:01 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-02 23:00 [PATCH v7 0/7] mtd: spi-nor: keep lock bits if they are non-volatile Michael Walle
2020-12-02 23:00 ` [PATCH v7 1/7] mtd: spi-nor: sst: fix BPn bits for the SST25VF064C Michael Walle
2020-12-03 14:34 ` Tudor.Ambarus
2020-12-03 14:39 ` Michael Walle
2020-12-03 15:08 ` Tudor.Ambarus
2020-12-03 18:24 ` Greg KH
2020-12-03 14:40 ` Tudor.Ambarus
2020-12-03 14:41 ` Michael Walle
2020-12-02 23:00 ` Michael Walle [this message]
2020-12-03 14:36 ` [PATCH v7 2/7] mtd: spi-nor: ignore errors in spi_nor_unlock_all() Tudor.Ambarus
2020-12-02 23:00 ` [PATCH v7 3/7] mtd: spi-nor: atmel: remove global protection flag Michael Walle
2020-12-02 23:00 ` [PATCH v7 4/7] mtd: spi-nor: sst: " Michael Walle
2020-12-02 23:00 ` [PATCH v7 5/7] mtd: spi-nor: intel: " Michael Walle
2020-12-02 23:00 ` [PATCH v7 6/7] mtd: spi-nor: atmel: fix unlock_all() for AT25FS010/040 Michael Walle
2020-12-03 14:44 ` Tudor.Ambarus
2020-12-02 23:00 ` [PATCH v7 7/7] mtd: spi-nor: keep lock bits if they are non-volatile Michael Walle
2020-12-03 14:51 ` Tudor.Ambarus
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201202230040.14009-3-michael@walle.cc \
--to=michael@walle.cc \
--cc=boris.brezillon@collabora.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=miquel.raynal@bootlin.com \
--cc=richard@nod.at \
--cc=tudor.ambarus@microchip.com \
--cc=vigneshr@ti.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).