author | Karl Beldan <kbeldan@baylibre.com> | |
Mon, 29 Aug 2016 07:45:49 +0000 (07:45 +0000) | ||
committer | Sasha Levin <alexander.levin@verizon.com> | |
Thu, 22 Dec 2016 03:45:42 +0000 (22:45 -0500) | ||
commit | 6b82b0601ac232d85a6728b9f6dfcb8160674a0c | |
tree | 039d7b7b172dd8c1b3a3753dfa69460ed1642bb5 | tree | snapshot (tar.xz tar.gz zip) |
parent | e537a0977f3ee837b6c101037c89936348063b2d | commit | diff |
mtd: nand: davinci: Reinitialize the HW ECC engine in 4bit hwctl
[ Upstream commit f6d7c1b5598b6407c3f1da795dd54acf99c1990c ]
This fixes subpage writes when using 4-bit HW ECC.
There has been numerous reports about ECC errors with devices using this
driver for a while. Also the 4-bit ECC has been reported as broken with
subpages in [1] and with 16 bits NANDs in the driver and in mach* board
files both in mainline and in the vendor BSPs.
What I saw with 4-bit ECC on a 16bits NAND (on an LCDK) which got me to
try reinitializing the ECC engine:
- R/W on whole pages properly generates/checks RS code
- try writing the 1st subpage only of a blank page, the subpage is well
written and the RS code properly generated, re-reading the same page
the HW detects some ECC error, reading the same page again no ECC
error is detected
Note that the ECC engine is already reinitialized in the 1-bit case.
Tested on my LCDK with UBI+UBIFS using subpages.
This could potentially get rid of the issue workarounded in [1].
[1] 28c015a9daab ("mtd: davinci-nand: disable subpage write for keystone-nand")
Fixes: 6a4123e581b3 ("mtd: nand: davinci_nand, 4-bit ECC for smallpage")
Cc: <stable@vger.kernel.org>
Signed-off-by: Karl Beldan <kbeldan@baylibre.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
[ Upstream commit f6d7c1b5598b6407c3f1da795dd54acf99c1990c ]
This fixes subpage writes when using 4-bit HW ECC.
There has been numerous reports about ECC errors with devices using this
driver for a while. Also the 4-bit ECC has been reported as broken with
subpages in [1] and with 16 bits NANDs in the driver and in mach* board
files both in mainline and in the vendor BSPs.
What I saw with 4-bit ECC on a 16bits NAND (on an LCDK) which got me to
try reinitializing the ECC engine:
- R/W on whole pages properly generates/checks RS code
- try writing the 1st subpage only of a blank page, the subpage is well
written and the RS code properly generated, re-reading the same page
the HW detects some ECC error, reading the same page again no ECC
error is detected
Note that the ECC engine is already reinitialized in the 1-bit case.
Tested on my LCDK with UBI+UBIFS using subpages.
This could potentially get rid of the issue workarounded in [1].
[1] 28c015a9daab ("mtd: davinci-nand: disable subpage write for keystone-nand")
Fixes: 6a4123e581b3 ("mtd: nand: davinci_nand, 4-bit ECC for smallpage")
Cc: <stable@vger.kernel.org>
Signed-off-by: Karl Beldan <kbeldan@baylibre.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
drivers/mtd/nand/davinci_nand.c | diff | blob | history |