On Sun, Dec 17, 2017 at 07:07:46PM +0100, Boris Brezillon wrote:
> > > This would guarantee that devices with factory bad blocks,
> > > (and no BBT), would be OK with this patch.
> >
> > I see. I'm fine with trying provided I have reasonably good assurance
> > that I won't have to go through the kwboot pain again :-/
>
> There's a easy test you can do without scrubing the NAND:
> 1/ comment the nand-on-flash-bbt property in your DT (this will trigger
> a full scan)
> 2/ from u-boot (before booting the kernel), erase a block that you know
> contains nothing important
> 3/ during the kernel scan, make sure this block is not reported as bad
OK so I tried and never faced any error. Thus I also attempted to mark
a bad block in u-boot, it appeared in the bad blocks table, then I had
to scrub the whole table to get rid of it. Each time when I booted I
saw the message "Scanning device for bad blocks" but no error ever
happened. So I hope it's OK.
Please find a summary of my tests below.
Marvell>> nand erase 280000 1000
NAND erase: device 0 offset 0x280000, size 0x1000
Erasing at 0x280000 -- 100% complete.
OK
Marvell>> nand dump 280000
Page 00280000 dump:
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
...
ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
OOB:
ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
ff ff ff ff ff ff ff ff
Boot....
# nanddump -c --oob --bb=dumpbad /dev/mtd8 >/tmp/dump-mtd8.txt
=> only ff everywhere
# dmesg
...
pxa3xx-nand f10d0000.flash: This platform can't do DMA on this device
nand: device found, Manufacturer ID: 0x01, Chip ID: 0xf1
nand: AMD/Spansion S34ML01G2
nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
pxa3xx-nand f10d0000.flash: ECC strength 16, ECC step size 2048
Scanning device for bad blocks
...
Marvell>> nand markbad 280000
Bad block table written to 0x000007fe0000, version 0x02
Bad block table written to 0x000007fc0000, version 0x02
>>> orion_nfc_wait_for_completion_timeout command timed out!, status (0x100)
command 19 execution timed out (CS -1, NDCR=0x8104bfff, NDSR=0x100).
block 0x00280000 successfully marked as bad
Marvell>>
Marvell>> nand bad
Device 0 bad blocks:
280000
7f00000
7f20000
7f40000
7f60000
7f80000
7fa0000
7fc0000
7fe0000
Boot...
# dmesg
...
[ 0.875117] pxa3xx-nand f10d0000.flash: This platform can't do DMA on this
device
[ 0.881627] nand: device found, Manufacturer ID: 0x01, Chip ID: 0xf1
[ 0.886697] nand: AMD/Spansion S34ML01G2
[ 0.889326] nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB
size: 64
[ 0.895628] pxa3xx-nand f10d0000.flash: ECC strength 16, ECC step size 2048
[ 0.901316] Scanning device for bad blocks
...
Marvell>> nand scrub 7f00000 100000
Erasing at 0x7fe0000 -- 100% complete.
Bad block table not found for chip 0
Bad block table not found for chip 0
Bad block table written to 0x000007fe0000, version 0x01
Bad block table written to 0x000007fc0000, version 0x01
OK
Marvell>> nand bad
Device 0 bad blocks:
7f00000
7f20000
7f40000
7f60000
7f80000
7fa0000
7fc0000
7fe0000
Boot...
# dmesg
...
[ 0.875322] pxa3xx-nand f10d0000.flash: This platform can't do DMA on this
device
[ 0.881834] nand: device found, Manufacturer ID: 0x01, Chip ID: 0xf1
[ 0.886904] nand: AMD/Spansion S34ML01G2
[ 0.889533] nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB
size: 64
[ 0.895835] pxa3xx-nand f10d0000.flash: ECC strength 16, ECC step size 2048
[ 0.901524] Scanning device for bad blocks
[ 1.202116] ata2: SATA link down (SStatus 0 SControl 300)
[ 1.206245] ata1: SATA link down (SStatus 0 SControl 300)
[ 1.244449] 10 ofpart partitions found on MTD device pxa3xx_nand-0
[ 1.249345] Creating 10 MTD partitions on "pxa3xx_nand-0":
[ 1.253551] 0x000000000000-0x000000200000 : "u-boot"
[ 1.257523] 0x000000200000-0x000000240000 : "u_env"
[ 1.261372] 0x000000240000-0x000000280000 : "s_env"
[ 1.265217] 0x000000900000-0x000000a00000 : "devinfo"
[ 1.269229] 0x000000a00000-0x000003200000 : "kernel1"
[ 1.273326] 0x000001000000-0x000003200000 : "rootfs1"
[ 1.277407] 0x000003200000-0x000005a00000 : "kernel2"
[ 1.281509] 0x000003800000-0x000005a00000 : "rootfs2"
[ 1.285591] 0x000005a00000-0x000008000000 : "syscfg"
[ 1.289596] 0x000000280000-0x000000900000 : "unused_area"
...
Willy
