On Tue, 2013-11-19 at 13:21 +0000, Gupta, Pekon wrote: > > From: Scott Wood [mailto:scottw...@freescale.com] > > > On Tue, Sep 10, 2013 at 12:55:07PM +0530, pekon gupta wrote: > > > With increase in NAND flash densities occurence of bit-flips has > > > increased. > > > Thus stronger ECC schemes are required for detecting and correcting > > multiple > > > simultaneous bit-flips in same NAND page. But stronger ECC schemes have > > large > > > ECC syndrome which require more space in OOB/Spare. > > > This patch add support for BCH16_ECC: > > > (a) BCH16_ECC can correct 16 bit-flips per 512Bytes of data. > > > (b) BCH16_ECC generates 26-bytes of ECC syndrome / 512B. > > > > > > Due to (b) this scheme can only be used with NAND devices which have > > enough > > > OOB to satisfy following equation: > > > OOBsize per page >= 26 * (page-size / 512) > > > > > > Signed-off-by: Pekon Gupta <pe...@ti.com> > > > > > > --- > > > arch/arm/include/asm/arch-am33xx/cpu.h | 15 ++++- > > > arch/arm/include/asm/arch-am33xx/omap_gpmc.h | 4 +- > > > drivers/mtd/nand/omap_gpmc.c | 87 > > +++++++++++++++++++++++----- > > > include/mtd/mtd-abi.h | 3 +- > > > 4 files changed, 90 insertions(+), 19 deletions(-) > > > > This doesn't apply cleanly. > > > This one is on top of previous patch series like.. > [Part 1] http://lists.denx.de/pipermail/u-boot/2013-November/167393.html > [Part 2] http://lists.denx.de/pipermail/u-boot/2013-November/167445.html > > So once the above series are cleaned and accepted. I'll rebase and re-send > this > series for BCH16 ecc-scheme again.. > > > > > diff --git a/arch/arm/include/asm/arch-am33xx/cpu.h > > b/arch/arm/include/asm/arch-am33xx/cpu.h > > > index 10b56e0..1de92e6 100644 > > > --- a/arch/arm/include/asm/arch-am33xx/cpu.h > > > +++ b/arch/arm/include/asm/arch-am33xx/cpu.h > > > @@ -63,7 +63,16 @@ struct gpmc_cs { > > > }; > > > > > > struct bch_res_0_3 { > > > - u32 bch_result_x[4]; > > > + u32 bch_result0; > > > + u32 bch_result1; > > > + u32 bch_result2; > > > + u32 bch_result3; > > > +}; > > > > Is this really an improvement? > > > Good for readability to match it to actual IP spec.. > Each of bch_resultx map to individual 32-bit registers named accordingly > in IP spec.
Hardware often names things "FOO1, FOO2, etc", but in C it's often better to express as foo[n] rather than foo1, foo2, etc. > > It would also be nice if headers for things in drivers/mtd/nand weren't > > in arch. > > > I agree.. but I would take that separately, as I need to test all other > platforms also for this change .. (like am335x, am43xx, omap3.. ) Yes, of course it would be separate. -Scott _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
