| Message ID | 1380916188-24206-2-git-send-email-pekon@ti.com |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 04, 2013 at 08:49:43PM +0100, Pekon Gupta wrote: > OMAP NAND driver currently supports multiple flavours of 1-bit Hamming > ecc-scheme, like: > - OMAP_ECC_HAMMING_CODE_DEFAULT > 1-bit hamming ecc code using software library > - OMAP_ECC_HAMMING_CODE_HW > 1-bit hamming ecc-code using GPMC h/w engine > - OMAP_ECC_HAMMING_CODE_HW_ROMCODE > 1-bit hamming ecc-code using GPMC h/w engin with ecc-layout compatible > to ROM code. > > This patch combines above multiple ecc-schemes into single implementation: > - OMAP_ECC_HAM1_CODE_HW > 1-bit hamming ecc-code using GPMC h/w engine with ROM-code compatible > ecc-layout. If I have my NAND formatted with one of the existing ECC schemes (e.g. OMAP_ECC_HAMMING_CODE_DEFAULT) will it work with the new OMAP_ECC_HAM1_CODE_HW scheme? Are they all compatible? > > Signed-off-by: Pekon Gupta <pekon@ti.com> > --- > Documentation/devicetree/bindings/mtd/gpmc-nand.txt | 8 ++++---- > arch/arm/mach-omap2/board-flash.c | 2 +- > arch/arm/mach-omap2/gpmc.c | 4 +--- > drivers/mtd/nand/omap2.c | 9 +++------ > include/linux/platform_data/mtd-nand-omap2.h | 6 +----- > 5 files changed, 10 insertions(+), 19 deletions(-) > > diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > index df338cb..25ee232 100644 > --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > +++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > @@ -22,10 +22,10 @@ Optional properties: > width of 8 is assumed. > > - ti,nand-ecc-opt: A string setting the ECC layout to use. One of: > - > - "sw" Software method (default) > - "hw" Hardware method > - "hw-romcode" gpmc hamming mode method & romcode layout > + "sw" <deprecated> use "ham1" instead > + "hw" <deprecated> use "ham1" instead > + "hw-romcode" <deprecated> use "ham1" instead > + "ham1" 1-bit Hamming ecc code > "bch4" 4-bit BCH ecc code > "bch8" 8-bit BCH ecc code > > diff --git a/arch/arm/mach-omap2/board-flash.c b/arch/arm/mach-omap2/board-flash.c > index fc20a61..ac82512 100644 > --- a/arch/arm/mach-omap2/board-flash.c > +++ b/arch/arm/mach-omap2/board-flash.c > @@ -142,7 +142,7 @@ __init board_nand_init(struct mtd_partition *nand_parts, u8 nr_parts, u8 cs, > board_nand_data.nr_parts = nr_parts; > board_nand_data.devsize = nand_type; > > - board_nand_data.ecc_opt = OMAP_ECC_HAMMING_CODE_DEFAULT; > + board_nand_data.ecc_opt = OMAP_ECC_BCH8_CODE_HW; > gpmc_nand_init(&board_nand_data, gpmc_t); > } > #endif /* CONFIG_MTD_NAND_OMAP2 || CONFIG_MTD_NAND_OMAP2_MODULE */ > diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c > index 9f4795a..1c45b72 100644 > --- a/arch/arm/mach-omap2/gpmc.c > +++ b/arch/arm/mach-omap2/gpmc.c > @@ -1342,9 +1342,7 @@ static void __maybe_unused gpmc_read_timings_dt(struct device_node *np, > #ifdef CONFIG_MTD_NAND > > static const char * const nand_ecc_opts[] = { > - [OMAP_ECC_HAMMING_CODE_DEFAULT] = "sw", > - [OMAP_ECC_HAMMING_CODE_HW] = "hw", > - [OMAP_ECC_HAMMING_CODE_HW_ROMCODE] = "hw-romcode", > + [OMAP_ECC_HAM1_CODE_HW] = "ham1", > [OMAP_ECC_BCH4_CODE_HW] = "bch4", > [OMAP_ECC_BCH8_CODE_HW] = "bch8", Won't this break existing dts which have "sw", "hw", or "hw-romcode"? Someone may try to use a new kernel with an old dt, and we marked them as deprecated, not removed. Thanks, Mark.
Hi, > From: Mark Rutland [mailto:mark.rutland@arm.com] > > On Fri, Oct 04, 2013 at 08:49:43PM +0100, Pekon Gupta wrote: > > OMAP NAND driver currently supports multiple flavours of 1-bit Hamming > > ecc-scheme, like: > > - OMAP_ECC_HAMMING_CODE_DEFAULT > > 1-bit hamming ecc code using software library > > - OMAP_ECC_HAMMING_CODE_HW > > 1-bit hamming ecc-code using GPMC h/w engine > > - OMAP_ECC_HAMMING_CODE_HW_ROMCODE > > 1-bit hamming ecc-code using GPMC h/w engin with ecc-layout > compatible > > to ROM code. > > > > This patch combines above multiple ecc-schemes into single > implementation: > > - OMAP_ECC_HAM1_CODE_HW > > 1-bit hamming ecc-code using GPMC h/w engine with ROM-code > compatible > > ecc-layout. > > If I have my NAND formatted with one of the existing ECC schemes (e.g. > OMAP_ECC_HAMMING_CODE_DEFAULT) will it work with the new > OMAP_ECC_HAM1_CODE_HW scheme? > > Are they all compatible? > Yes, they all are 1-bit hamming code, the only difference between xx_Default and xx_HW was who was doing the ECC calculation. For xx_DEFAULT: ECC calculation was done on CPU via s/w library For xx_HW: ECC calculation was done by in-build h/w engine. So, all HAMMING_xx can be replaced by HAM1_HW. [snip] > > @@ -1342,9 +1342,7 @@ static void __maybe_unused > gpmc_read_timings_dt(struct device_node *np, > > #ifdef CONFIG_MTD_NAND > > > > static const char * const nand_ecc_opts[] = { > > - [OMAP_ECC_HAMMING_CODE_DEFAULT] = "sw", > > - [OMAP_ECC_HAMMING_CODE_HW] = "hw", > > - [OMAP_ECC_HAMMING_CODE_HW_ROMCODE] = "hw- > romcode", > > + [OMAP_ECC_HAM1_CODE_HW] = "ham1", > > [OMAP_ECC_BCH4_CODE_HW] = "bch4", > > [OMAP_ECC_BCH8_CODE_HW] = "bch8", > > Won't this break existing dts which have "sw", "hw", or "hw-romcode"? > > Someone may try to use a new kernel with an old dt, and we marked them > as deprecated, not removed. > HAMMING_xx ECC scheme was used only on legacy platforms, when BCH8 was not available, I have not seen anyone using this scheme *from mainline kernel* from quite a long time. So, it's safe to remove them. This is what was concluded as per below email. http://lists.infradead.org/pipermail/linux-mtd/2013-September/048876.html with regards, pekon
Dear MTD Maintainers, > > > > If I have my NAND formatted with one of the existing ECC schemes (e.g. > > OMAP_ECC_HAMMING_CODE_DEFAULT) will it work with the new > > OMAP_ECC_HAM1_CODE_HW scheme? > > > > Are they all compatible? > > > Yes, they all are 1-bit hamming code, the only difference between > xx_Default and xx_HW was who was doing the ECC calculation. > For xx_DEFAULT: ECC calculation was done on CPU via s/w library > For xx_HW: ECC calculation was done by in-build h/w engine. > So, all HAMMING_xx can be replaced by HAM1_HW. > > [snip] > > > > @@ -1342,9 +1342,7 @@ static void __maybe_unused > > gpmc_read_timings_dt(struct device_node *np, > > > #ifdef CONFIG_MTD_NAND > > > > > > static const char * const nand_ecc_opts[] = { > > > - [OMAP_ECC_HAMMING_CODE_DEFAULT] = "sw", > > > - [OMAP_ECC_HAMMING_CODE_HW] = "hw", > > > - [OMAP_ECC_HAMMING_CODE_HW_ROMCODE] = "hw- > > romcode", > > > + [OMAP_ECC_HAM1_CODE_HW] = "ham1", > > > [OMAP_ECC_BCH4_CODE_HW] = "bch4", > > > [OMAP_ECC_BCH8_CODE_HW] = "bch8", > > > > Won't this break existing dts which have "sw", "hw", or "hw-romcode"? > > > > Someone may try to use a new kernel with an old dt, and we marked them > > as deprecated, not removed. > > > HAMMING_xx ECC scheme was used only on legacy platforms, when > BCH8 was not available, I have not seen anyone using this scheme > *from mainline kernel* from quite a long time. So, it's safe to remove them. > > This is what was concluded as per below email. > http://lists.infradead.org/pipermail/linux-mtd/2013-September/048876.html > This patch-series and its follow-on series has already missed many merge windows, And the above discussion has reached a stalled state (infinite loop) where, I cannot revert some DT binding updates to and fro to keep all legacy DT bindings backward compatible forever. However, I can assure that these DT updates make binding stable for long-term. So now it's your discretion to whether to accept or leave following 2 series: http://lists.infradead.org/pipermail/linux-mtd/2013-October/048983.html http://lists.infradead.org/pipermail/linux-mtd/2013-October/049008.html AFAIK no-one is using Hamming based ecc-scheme on OMAP platforms *from mainline kernel*. So this DT update actually does not affect users I know of. Rather these patch series was intended for long term scalability and clean-up so that more OMAP users migrate to mainline kernel easily. with regards, pekon
diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt index df338cb..25ee232 100644 --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt +++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt @@ -22,10 +22,10 @@ Optional properties: width of 8 is assumed. - ti,nand-ecc-opt: A string setting the ECC layout to use. One of: - - "sw" Software method (default) - "hw" Hardware method - "hw-romcode" gpmc hamming mode method & romcode layout + "sw" <deprecated> use "ham1" instead + "hw" <deprecated> use "ham1" instead + "hw-romcode" <deprecated> use "ham1" instead + "ham1" 1-bit Hamming ecc code "bch4" 4-bit BCH ecc code "bch8" 8-bit BCH ecc code diff --git a/arch/arm/mach-omap2/board-flash.c b/arch/arm/mach-omap2/board-flash.c index fc20a61..ac82512 100644 --- a/arch/arm/mach-omap2/board-flash.c +++ b/arch/arm/mach-omap2/board-flash.c @@ -142,7 +142,7 @@ __init board_nand_init(struct mtd_partition *nand_parts, u8 nr_parts, u8 cs, board_nand_data.nr_parts = nr_parts; board_nand_data.devsize = nand_type; - board_nand_data.ecc_opt = OMAP_ECC_HAMMING_CODE_DEFAULT; + board_nand_data.ecc_opt = OMAP_ECC_BCH8_CODE_HW; gpmc_nand_init(&board_nand_data, gpmc_t); } #endif /* CONFIG_MTD_NAND_OMAP2 || CONFIG_MTD_NAND_OMAP2_MODULE */ diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index 9f4795a..1c45b72 100644 --- a/arch/arm/mach-omap2/gpmc.c +++ b/arch/arm/mach-omap2/gpmc.c @@ -1342,9 +1342,7 @@ static void __maybe_unused gpmc_read_timings_dt(struct device_node *np, #ifdef CONFIG_MTD_NAND static const char * const nand_ecc_opts[] = { - [OMAP_ECC_HAMMING_CODE_DEFAULT] = "sw", - [OMAP_ECC_HAMMING_CODE_HW] = "hw", - [OMAP_ECC_HAMMING_CODE_HW_ROMCODE] = "hw-romcode", + [OMAP_ECC_HAM1_CODE_HW] = "ham1", [OMAP_ECC_BCH4_CODE_HW] = "bch4", [OMAP_ECC_BCH8_CODE_HW] = "bch8", }; diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 4ecf0e5..8d521aa 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -1993,10 +1993,7 @@ static int omap_nand_probe(struct platform_device *pdev) } /* select the ecc type */ - if (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_DEFAULT) - info->nand.ecc.mode = NAND_ECC_SOFT; - else if ((pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW) || - (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW_ROMCODE)) { + if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) { info->nand.ecc.bytes = 3; info->nand.ecc.size = 512; info->nand.ecc.strength = 1; @@ -2025,7 +2022,7 @@ static int omap_nand_probe(struct platform_device *pdev) } /* rom code layout */ - if (pdata->ecc_opt == OMAP_ECC_HAMMING_CODE_HW_ROMCODE) { + if (pdata->ecc_opt == OMAP_ECC_HAM1_CODE_HW) { if (info->nand.options & NAND_BUSWIDTH_16) offset = 2; @@ -2033,7 +2030,7 @@ static int omap_nand_probe(struct platform_device *pdev) offset = 1; info->nand.badblock_pattern = &bb_descrip_flashbased; } - omap_oobinfo.eccbytes = 3 * (info->mtd.oobsize/16); + omap_oobinfo.eccbytes = 3 * (info->mtd.writesize / 512); for (i = 0; i < omap_oobinfo.eccbytes; i++) omap_oobinfo.eccpos[i] = i+offset; diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux/platform_data/mtd-nand-omap2.h index 6bf9ef4..cb5a54a 100644 --- a/include/linux/platform_data/mtd-nand-omap2.h +++ b/include/linux/platform_data/mtd-nand-omap2.h @@ -23,11 +23,7 @@ enum nand_io { }; enum omap_ecc { - /* 1-bit ecc: stored at end of spare area */ - OMAP_ECC_HAMMING_CODE_DEFAULT = 0, /* Default, s/w method */ - OMAP_ECC_HAMMING_CODE_HW, /* gpmc to detect the error */ - /* 1-bit ecc: stored at beginning of spare area as romcode */ - OMAP_ECC_HAMMING_CODE_HW_ROMCODE, /* gpmc method & romcode layout */ + OMAP_ECC_HAM1_CODE_HW = 0, /* 1-bit Hamming ecc code */ OMAP_ECC_BCH4_CODE_HW, /* 4-bit BCH ecc code */ OMAP_ECC_BCH8_CODE_HW, /* 8-bit BCH ecc code */ };
OMAP NAND driver currently supports multiple flavours of 1-bit Hamming ecc-scheme, like: - OMAP_ECC_HAMMING_CODE_DEFAULT 1-bit hamming ecc code using software library - OMAP_ECC_HAMMING_CODE_HW 1-bit hamming ecc-code using GPMC h/w engine - OMAP_ECC_HAMMING_CODE_HW_ROMCODE 1-bit hamming ecc-code using GPMC h/w engin with ecc-layout compatible to ROM code. This patch combines above multiple ecc-schemes into single implementation: - OMAP_ECC_HAM1_CODE_HW 1-bit hamming ecc-code using GPMC h/w engine with ROM-code compatible ecc-layout. Signed-off-by: Pekon Gupta <pekon@ti.com> --- Documentation/devicetree/bindings/mtd/gpmc-nand.txt | 8 ++++---- arch/arm/mach-omap2/board-flash.c | 2 +- arch/arm/mach-omap2/gpmc.c | 4 +--- drivers/mtd/nand/omap2.c | 9 +++------ include/linux/platform_data/mtd-nand-omap2.h | 6 +----- 5 files changed, 10 insertions(+), 19 deletions(-)