[PATCH 3/3] mtd: spinand: Wait for the erase op to finish before writing a bad block marker
From: Frieder Schrempf frieder.schrempf@kontron.de
Currently when marking a block, we use spinand_erase_op() to erase the block before writing the marker to the OOB area without waiting for the operation to succeed. This can lead to the marking failing silently and no bad block marker being written to the flash.
To fix this we reuse the spinand_erase() function, that already does everything we need to do before actually writing the marker.
Fixes: 7529df465248 ("mtd: nand: Add core infrastructure to support SPI NANDs") Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf frieder.schrempf@kontron.de --- drivers/mtd/nand/spi/core.c | 56 ++++++++++++++++++------------------- 1 file changed, 28 insertions(+), 28 deletions(-)
diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c index 925db6269861..8a69d13639e2 100644 --- a/drivers/mtd/nand/spi/core.c +++ b/drivers/mtd/nand/spi/core.c @@ -600,6 +600,32 @@ static int spinand_mtd_block_isbad(struct mtd_info *mtd, loff_t offs) return ret; }
+static int __spinand_erase(struct nand_device *nand, const struct nand_pos *pos, + bool hard_fail) +{ + struct spinand_device *spinand = nand_to_spinand(nand); + u8 status; + int ret; + + ret = spinand_select_target(spinand, pos->target); + if (ret) + return ret; + + ret = spinand_write_enable_op(spinand); + if (ret) + return ret; + + ret = spinand_erase_op(spinand, pos); + if (ret && hard_fail) + return ret; + + ret = spinand_wait(spinand, &status); + if (!ret && (status & STATUS_ERASE_FAILED)) + ret = -EIO; + + return ret; +} + static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) { struct spinand_device *spinand = nand_to_spinand(nand); @@ -614,16 +640,10 @@ static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) int ret;
/* Erase block before marking it bad. */ - ret = spinand_select_target(spinand, pos->target); - if (ret) - return ret; - - ret = spinand_write_enable_op(spinand); + ret = __spinand_erase(nand, pos, false); if (ret) return ret;
- spinand_erase_op(spinand, pos); - return spinand_write_page(spinand, &req); }
@@ -644,27 +664,7 @@ static int spinand_mtd_block_markbad(struct mtd_info *mtd, loff_t offs)
static int spinand_erase(struct nand_device *nand, const struct nand_pos *pos) { - struct spinand_device *spinand = nand_to_spinand(nand); - u8 status; - int ret; - - ret = spinand_select_target(spinand, pos->target); - if (ret) - return ret; - - ret = spinand_write_enable_op(spinand); - if (ret) - return ret; - - ret = spinand_erase_op(spinand, pos); - if (ret) - return ret; - - ret = spinand_wait(spinand, &status); - if (!ret && (status & STATUS_ERASE_FAILED)) - ret = -EIO; - - return ret; + return __spinand_erase(nand, pos, true); }
static int spinand_mtd_erase(struct mtd_info *mtd,
Hi Frieder,
Schrempf Frieder frieder.schrempf@kontron.de wrote on Tue, 11 Feb 2020 16:35:53 +0000:
From: Frieder Schrempf frieder.schrempf@kontron.de
Currently when marking a block, we use spinand_erase_op() to erase the block before writing the marker to the OOB area without waiting for the operation to succeed. This can lead to the marking failing silently and no bad block marker being written to the flash.
To fix this we reuse the spinand_erase() function, that already does everything we need to do before actually writing the marker.
Thanks a lot for this series!
Yet I don't really understand the point of waiting for the erasure if it failed: we don't really care as programming (1 -> 0) cells is always possible. Are you sure this lead to an error?
Also, why just not calling spinand_erase() instead of spinand_erase_op() from spinand_markbad()?
Fixes: 7529df465248 ("mtd: nand: Add core infrastructure to support SPI NANDs") Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf frieder.schrempf@kontron.de
drivers/mtd/nand/spi/core.c | 56 ++++++++++++++++++------------------- 1 file changed, 28 insertions(+), 28 deletions(-)
diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c index 925db6269861..8a69d13639e2 100644 --- a/drivers/mtd/nand/spi/core.c +++ b/drivers/mtd/nand/spi/core.c @@ -600,6 +600,32 @@ static int spinand_mtd_block_isbad(struct mtd_info *mtd, loff_t offs) return ret; } +static int __spinand_erase(struct nand_device *nand, const struct nand_pos *pos,
bool hard_fail)+{
- struct spinand_device *spinand = nand_to_spinand(nand);
- u8 status;
- int ret;
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- if (ret)
return ret;- ret = spinand_erase_op(spinand, pos);
- if (ret && hard_fail)
return ret;- ret = spinand_wait(spinand, &status);
- if (!ret && (status & STATUS_ERASE_FAILED))
ret = -EIO;- return ret;
+}
static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) { struct spinand_device *spinand = nand_to_spinand(nand); @@ -614,16 +640,10 @@ static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) int ret; /* Erase block before marking it bad. */
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- ret = __spinand_erase(nand, pos, false); if (ret) return ret;
- spinand_erase_op(spinand, pos);
- return spinand_write_page(spinand, &req);
} @@ -644,27 +664,7 @@ static int spinand_mtd_block_markbad(struct mtd_info *mtd, loff_t offs) static int spinand_erase(struct nand_device *nand, const struct nand_pos *pos) {
- struct spinand_device *spinand = nand_to_spinand(nand);
- u8 status;
- int ret;
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- if (ret)
return ret;- ret = spinand_erase_op(spinand, pos);
- if (ret)
return ret;- ret = spinand_wait(spinand, &status);
- if (!ret && (status & STATUS_ERASE_FAILED))
ret = -EIO;- return ret;
- return __spinand_erase(nand, pos, true);
} static int spinand_mtd_erase(struct mtd_info *mtd,
Thanks, Miquèl
On Mon, 17 Feb 2020 11:39:19 +0100 Miquel Raynal miquel.raynal@bootlin.com wrote:
Hi Frieder,
Schrempf Frieder frieder.schrempf@kontron.de wrote on Tue, 11 Feb 2020 16:35:53 +0000:
From: Frieder Schrempf frieder.schrempf@kontron.de
Currently when marking a block, we use spinand_erase_op() to erase the block before writing the marker to the OOB area without waiting for the operation to succeed. This can lead to the marking failing silently and no bad block marker being written to the flash.
To fix this we reuse the spinand_erase() function, that already does everything we need to do before actually writing the marker.
Thanks a lot for this series!
Yet I don't really understand the point of waiting for the erasure if it failed: we don't really care as programming (1 -> 0) cells is always possible. Are you sure this lead to an error?
Actually, I think I already pointed out that we should probably write the BBM without erasing the block. IIRC, this logic has been copied from rawnand where some controllers don't disable the ECC engine when doing raw accesses, leading to ECC errors if the block is not erased before BBMs are programmed. Assuming we don't let such drivers being merged in spinand, this erase operation can be dropped.
Also, why just not calling spinand_erase() instead of spinand_erase_op() from spinand_markbad()?
Fixes: 7529df465248 ("mtd: nand: Add core infrastructure to support SPI NANDs") Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf frieder.schrempf@kontron.de
drivers/mtd/nand/spi/core.c | 56 ++++++++++++++++++------------------- 1 file changed, 28 insertions(+), 28 deletions(-)
diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c index 925db6269861..8a69d13639e2 100644 --- a/drivers/mtd/nand/spi/core.c +++ b/drivers/mtd/nand/spi/core.c @@ -600,6 +600,32 @@ static int spinand_mtd_block_isbad(struct mtd_info *mtd, loff_t offs) return ret; } +static int __spinand_erase(struct nand_device *nand, const struct nand_pos *pos,
bool hard_fail)
I hate those __ prefix. Please find a more descriptive name (spinand_erase_block() or spinand_erase_and_wait()?)
+{
- struct spinand_device *spinand = nand_to_spinand(nand);
- u8 status;
- int ret;
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- if (ret)
return ret;- ret = spinand_erase_op(spinand, pos);
- if (ret && hard_fail)
return ret;- ret = spinand_wait(spinand, &status);
- if (!ret && (status & STATUS_ERASE_FAILED))
ret = -EIO;- return ret;
+}
static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) { struct spinand_device *spinand = nand_to_spinand(nand); @@ -614,16 +640,10 @@ static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) int ret; /* Erase block before marking it bad. */
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- ret = __spinand_erase(nand, pos, false); if (ret) return ret;
- spinand_erase_op(spinand, pos);
- return spinand_write_page(spinand, &req);
} @@ -644,27 +664,7 @@ static int spinand_mtd_block_markbad(struct mtd_info *mtd, loff_t offs) static int spinand_erase(struct nand_device *nand, const struct nand_pos *pos) {
- struct spinand_device *spinand = nand_to_spinand(nand);
- u8 status;
- int ret;
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- if (ret)
return ret;- ret = spinand_erase_op(spinand, pos);
- if (ret)
return ret;- ret = spinand_wait(spinand, &status);
- if (!ret && (status & STATUS_ERASE_FAILED))
ret = -EIO;- return ret;
- return __spinand_erase(nand, pos, true);
} static int spinand_mtd_erase(struct mtd_info *mtd,
Thanks, Miquèl
Hi Boris,
On 17.02.20 12:14, Boris Brezillon wrote:
On Mon, 17 Feb 2020 11:39:19 +0100 Miquel Raynal miquel.raynal@bootlin.com wrote:
Hi Frieder,
Schrempf Frieder frieder.schrempf@kontron.de wrote on Tue, 11 Feb 2020 16:35:53 +0000:
From: Frieder Schrempf frieder.schrempf@kontron.de
Currently when marking a block, we use spinand_erase_op() to erase the block before writing the marker to the OOB area without waiting for the operation to succeed. This can lead to the marking failing silently and no bad block marker being written to the flash.
To fix this we reuse the spinand_erase() function, that already does everything we need to do before actually writing the marker.
Thanks a lot for this series!
Yet I don't really understand the point of waiting for the erasure if it failed: we don't really care as programming (1 -> 0) cells is always possible. Are you sure this lead to an error?
Actually, I think I already pointed out that we should probably write the BBM without erasing the block. IIRC, this logic has been copied from rawnand where some controllers don't disable the ECC engine when doing raw accesses, leading to ECC errors if the block is not erased before BBMs are programmed. Assuming we don't let such drivers being merged in spinand, this erase operation can be dropped.
You're probably right, we could also just write the BBM without erasing the block. I will try if this works in my setup and update the patch.
Also, why just not calling spinand_erase() instead of spinand_erase_op() from spinand_markbad()?
Fixes: 7529df465248 ("mtd: nand: Add core infrastructure to support SPI NANDs") Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf frieder.schrempf@kontron.de
drivers/mtd/nand/spi/core.c | 56 ++++++++++++++++++------------------- 1 file changed, 28 insertions(+), 28 deletions(-)
diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c index 925db6269861..8a69d13639e2 100644 --- a/drivers/mtd/nand/spi/core.c +++ b/drivers/mtd/nand/spi/core.c @@ -600,6 +600,32 @@ static int spinand_mtd_block_isbad(struct mtd_info *mtd, loff_t offs) return ret; } +static int __spinand_erase(struct nand_device *nand, const struct nand_pos *pos,
bool hard_fail)I hate those __ prefix. Please find a more descriptive name (spinand_erase_block() or spinand_erase_and_wait()?)
Actually I was expecting this comment ;) And I totally agree. I was just lazy to come up with a name. If we follow the approach without erase, I can get rid of this anyway.
Thanks, Frieder
+{
- struct spinand_device *spinand = nand_to_spinand(nand);
- u8 status;
- int ret;
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- if (ret)
return ret;- ret = spinand_erase_op(spinand, pos);
- if (ret && hard_fail)
return ret;- ret = spinand_wait(spinand, &status);
- if (!ret && (status & STATUS_ERASE_FAILED))
ret = -EIO;- return ret;
+}
- static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) { struct spinand_device *spinand = nand_to_spinand(nand);
@@ -614,16 +640,10 @@ static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) int ret; /* Erase block before marking it bad. */
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- ret = __spinand_erase(nand, pos, false); if (ret) return ret;
- spinand_erase_op(spinand, pos);
- return spinand_write_page(spinand, &req); }
@@ -644,27 +664,7 @@ static int spinand_mtd_block_markbad(struct mtd_info *mtd, loff_t offs) static int spinand_erase(struct nand_device *nand, const struct nand_pos *pos) {
- struct spinand_device *spinand = nand_to_spinand(nand);
- u8 status;
- int ret;
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- if (ret)
return ret;- ret = spinand_erase_op(spinand, pos);
- if (ret)
return ret;- ret = spinand_wait(spinand, &status);
- if (!ret && (status & STATUS_ERASE_FAILED))
ret = -EIO;- return ret;
- return __spinand_erase(nand, pos, true); }
static int spinand_mtd_erase(struct mtd_info *mtd,
Thanks, Miquèl
Hi Miquel,
On 17.02.20 11:39, Miquel Raynal wrote:
Hi Frieder,
Schrempf Frieder frieder.schrempf@kontron.de wrote on Tue, 11 Feb 2020 16:35:53 +0000:
From: Frieder Schrempf frieder.schrempf@kontron.de
Currently when marking a block, we use spinand_erase_op() to erase the block before writing the marker to the OOB area without waiting for the operation to succeed. This can lead to the marking failing silently and no bad block marker being written to the flash.
To fix this we reuse the spinand_erase() function, that already does everything we need to do before actually writing the marker.
Thanks a lot for this series!
Yet I don't really understand the point of waiting for the erasure if it failed: we don't really care as programming (1 -> 0) cells is always possible. Are you sure this lead to an error?
We don't care about the result of the erase operation, but I think we still need to wait for it to be done and the STATUS_BUSY bit to be cleared. Otherwise it seems like the program operation to set the marker can get ignored by the chip. At least that's my explanation for the behavior I was observing.
Also, why just not calling spinand_erase() instead of spinand_erase_op() from spinand_markbad()?
Yeah, that's wrong. I was thinking, that spinand_erase_op() would return an error if the erase failed on the flash level (which should have been ignored in this case). The current code suggested this as it doesn't handle the return value of spinand_erase_op().
But in fact the success of the erase operation is only checked in spinand_erase() after waiting for the flash to be ready. So I think we can use spinand_erase(), but instead of ignoring the return value of spinand_erase_op(), we need to ignore the 'status & STATUS_ERASE_FAILED' check.
Thanks, Frieder
Fixes: 7529df465248 ("mtd: nand: Add core infrastructure to support SPI NANDs") Cc: stable@vger.kernel.org Signed-off-by: Frieder Schrempf frieder.schrempf@kontron.de
drivers/mtd/nand/spi/core.c | 56 ++++++++++++++++++------------------- 1 file changed, 28 insertions(+), 28 deletions(-)
diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c index 925db6269861..8a69d13639e2 100644 --- a/drivers/mtd/nand/spi/core.c +++ b/drivers/mtd/nand/spi/core.c @@ -600,6 +600,32 @@ static int spinand_mtd_block_isbad(struct mtd_info *mtd, loff_t offs) return ret; } +static int __spinand_erase(struct nand_device *nand, const struct nand_pos *pos,
bool hard_fail)+{
- struct spinand_device *spinand = nand_to_spinand(nand);
- u8 status;
- int ret;
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- if (ret)
return ret;- ret = spinand_erase_op(spinand, pos);
- if (ret && hard_fail)
return ret;- ret = spinand_wait(spinand, &status);
- if (!ret && (status & STATUS_ERASE_FAILED))
ret = -EIO;- return ret;
+}
- static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) { struct spinand_device *spinand = nand_to_spinand(nand);
@@ -614,16 +640,10 @@ static int spinand_markbad(struct nand_device *nand, const struct nand_pos *pos) int ret; /* Erase block before marking it bad. */
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- ret = __spinand_erase(nand, pos, false); if (ret) return ret;
- spinand_erase_op(spinand, pos);
- return spinand_write_page(spinand, &req); }
@@ -644,27 +664,7 @@ static int spinand_mtd_block_markbad(struct mtd_info *mtd, loff_t offs) static int spinand_erase(struct nand_device *nand, const struct nand_pos *pos) {
- struct spinand_device *spinand = nand_to_spinand(nand);
- u8 status;
- int ret;
- ret = spinand_select_target(spinand, pos->target);
- if (ret)
return ret;- ret = spinand_write_enable_op(spinand);
- if (ret)
return ret;- ret = spinand_erase_op(spinand, pos);
- if (ret)
return ret;- ret = spinand_wait(spinand, &status);
- if (!ret && (status & STATUS_ERASE_FAILED))
ret = -EIO;- return ret;
- return __spinand_erase(nand, pos, true); }
static int spinand_mtd_erase(struct mtd_info *mtd,
Thanks, Miquèl
From: Schrempf Frieder
Sent: 17 February 2020 11:19
Schrempf Frieder frieder.schrempf@kontron.de wrote on Tue, 11 Feb 2020 16:35:53 +0000:
From: Frieder Schrempf frieder.schrempf@kontron.de
Currently when marking a block, we use spinand_erase_op() to erase the block before writing the marker to the OOB area without waiting for the operation to succeed. This can lead to the marking failing silently and no bad block marker being written to the flash.
To fix this we reuse the spinand_erase() function, that already does everything we need to do before actually writing the marker.
Thanks a lot for this series!
Yet I don't really understand the point of waiting for the erasure if it failed: we don't really care as programming (1 -> 0) cells is always possible. Are you sure this lead to an error?
We don't care about the result of the erase operation, but I think we still need to wait for it to be done and the STATUS_BUSY bit to be cleared. Otherwise it seems like the program operation to set the marker can get ignored by the chip. At least that's my explanation for the behavior I was observing.
Serial flash devices won't allow any accesses while an erase or write in in progress. So while you don't need to wait for either to finish, you do need to remember that one is 'pending' and wait for it to finish before any further accesses (apart from reads of the status register).
How many writes you can do to an area (that clear 1s) and the size of the area will be device dependant. IIRC one device I've used allows 2 writes to each 16bit word. This allows either two separate byte writes or one write of a 16bit (or 32bit) value followed by a second write of all 0s the 'erase' the value without doing a erase-rewrite cycle.
David
- Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
linux-stable-mirror@lists.linaro.org
-
Boris Brezillon -
David Laight -
Miquel Raynal -
Schrempf Frieder