On 01/14/2014 09:21 PM, Scott Wood wrote:
On Tue, 2014-01-14 at 21:11 +0100, Jeroen Hofstee wrote:
Hello Scott, Pekon,
On 01/13/2014 07:18 PM, Scott Wood wrote:
The omap_gpmc allows switching ecc at runtime. Since the NAND_SUBPAGE_READ flag is only set, it is kept when switching to hw ecc, which is not correct. This leads to calling chip->ecc.read_subpage which is not a valid pointer. Therefore also clear the flag so reading in hw mode works again.
Cc: Scott Wood scottwood@freescale.com Cc: Pekon Gupta pekon@ti.com Cc: Nikita Kiryanov nikita@compulab.co.il Signed-off-by: Jeroen Hofstee jeroen@myspectrum.nl
drivers/mtd/nand/nand_base.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 1ce55fd..0762a19 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -3354,6 +3354,8 @@ int nand_scan_tail(struct mtd_info *mtd) /* Large page NAND with SOFT_ECC should support subpage reads */ if ((chip->ecc.mode == NAND_ECC_SOFT) && (chip->page_shift > 9)) chip->options |= NAND_SUBPAGE_READ;
- else
chip->options &= ~NAND_SUBPAGE_READ;NACK; this breaks NAND_SUBPAGE_READ with hardware ECC for drivers that support it.
There is something to argue in favour of that in general, but there are no such drivers in u-boot at the moment though (well at least not doing it on purpose). I don't mind moving it to gpmc, but for correctness, it doesn't break things at the moment...
It doesn't matter if there are any such drivers at the moment. It's a bad change, and a gratuitous difference from Linux with which we share this common code.
of course it does matter, you can chose not to support certain features, like subpage reads, interrupts, power management etc in a bootloader. As I said, moving it to gpmc is fine with me, so lets not making a long discussion of it.
All the other cleanup required to change ECC modes is handled by the OMAP driver; why shouldn't this be as well?
If there are more architectures, who think it is brilliant to switch ecc it will become a mesh if not coped with in general. And yes omap might be the exception for now, so lets put it there.
Regards, Jeroen