On Thu, 18 Oct 2018 at 14:29, Koen Vandeputte <[email protected]> wrote: > starting from upstream commit 577b4eb23811 ("ubi: Reject MLC NAND") > it is not allowed to use UBI and UBIFS on a MLC flavoured NAND flash chip. [1] > > According to David Oberhollenzer [2]: > > The real problem is that on MLC NAND, pages come in pairs. > > Multiple voltage levels inside a single, physical memory cell are used to > encode more than one bit. Instead of just having pages that are twice as big, > the flash exposes them as *two different pages*. Those pages are usually not > ordered sequentially either, but according to a vendor/device specific > pairing scheme. > > Within OpenWrt, devices utilizing this type of flash, > combined with ubi(fs) will be bricked when a user upgrades > from 17.01.4 to a newer version as the MLC will be refused.
We should disable building images for those unsupported devices. Could you provide a list of devices using MLC & "supported" by OpenWrt, please? Or even better a patch disabling images for them? > As these devices are currently advertised as supported by OpenWrt, > we should at least maintain the original state during the lifecycle > of the current releases. > > Support can be gracefully ended when a new release-branch is created. > > Signed-off-by: Koen Vandeputte <[email protected]> > > [1] > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=v4.14.77&id=577b4eb23811dfc8e38924dc476dbc866be74253 > [2] https://lore.kernel.org/patchwork/patch/920344/ > --- > > Mainly intended for discussion first on this approach before applying it. > Can be cherrypicked to 18.06. > > Feel free to drop your (n)ack on this approach Well, MAYBE, we could push this to the openwrt-18.06. I'm not sure about this. Upstream developers decided to drop MLC support completely even for stable kernels (Cc: stable@). _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/mailman/listinfo/openwrt-devel
