diff options
| author | Karl Beldan <kbeldan@baylibre.com> | 2016-08-29 07:45:49 +0000 |
|---|---|---|
| committer | Brian Norris <computersforpeace@gmail.com> | 2016-09-09 19:39:33 -0700 |
| commit | f6d7c1b5598b6407c3f1da795dd54acf99c1990c (patch) | |
| tree | ce58b3665a858c93eb36830c65730d91c03c1398 /drivers | |
| parent | a93295a7e118b5c58391906e47183775b1eb7cb1 (diff) | |
| download | linux-0-day-f6d7c1b5598b6407c3f1da795dd54acf99c1990c.tar.gz linux-0-day-f6d7c1b5598b6407c3f1da795dd54acf99c1990c.tar.xz | |
mtd: nand: davinci: Reinitialize the HW ECC engine in 4bit hwctl
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mtd/nand/davinci_nand.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/mtd/nand/davinci_nand.c b/drivers/mtd/nand/davinci_nand.c index cc07ba0f044de..27fa8b87cd5fc 100644 --- a/drivers/mtd/nand/davinci_nand.c +++ b/drivers/mtd/nand/davinci_nand.c @@ -240,6 +240,9 @@ static void nand_davinci_hwctl_4bit(struct mtd_info *mtd, int mode) unsigned long flags; u32 val; + /* Reset ECC hardware */ + davinci_nand_readl(info, NAND_4BIT_ECC1_OFFSET); + spin_lock_irqsave(&davinci_nand_lock, flags); /* Start 4-bit ECC calculation for read/write */ |