Hello, On 24 May 2016 at 11:29, Zaahir Khan <kn.zahirk...@gmail.com> wrote: > > Hi All, > > We are using customized A20 based on Cubie2 Board. Android 4.2.2 Source > from third party "a20_sdk30". > > Using SK Hynix NAND H27UCG8T2BTR 8GB. > > Board was not booting up, so when tried to re-flash using Livesuite could > find the large number of Bad block, livesuite serial log snip below. ... > > Noticed that when frequently using h/w reset(100-500 times) there is rise in > Bad Block count.
That's definitely not good for the nand. Losing power during write should not cause permanent damage beyond normal wear but it can corrupt the filesystem and cause it to detect blocks as bad or create random bit patterns looking like whatever the Allwinner driver uses as bad block markers. If you see corruption there is some problem with the reset although the board itself does not lose power. Maybe the nand loses power/is reset early during the boot sequence. > > Need some help to resolve this issue. Use a SD card. It can be replaced when it wears down. It uses it's own internal wear levelling. It may even be faster if you get a decent quality one. Another alternative is to net-boot or attach some additional storage if you need the SD slot for your application. Note that using the nand read-only for booting and then loading the system from other storage not supported by the SoC bootloader is ok. Writing to it causes problems. > > What can be the possible reason for rise in Bad block? > > For testing purpose modified the Boot1 code with NAND_EraseChip() API call, > could find reduction in bad block count when using LiveSuit next time. So my > guess is these Bad Block count is not the actual one. > > Is it possible to clear bad block? You can overwrite the markers and cause the bad blocks to be re-detected during normal use. You also lose erase counts (hopefully the Allwinner code has some) so that's not awesome either. HTH Michal -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
