On Wednesday, 29 April 2020 18:53:47 CET Ronald G. Minnich wrote: > From: Boris Brezillon > > Looks like some drivers define MTD names with a colon in it, thus > making mtdpart= parsing impossible. Let's fix the parser to gracefully > handle that case: the last ':' in a partition definition sequence is > considered instead of the first one. > > Signed-off-by: Boris Brezillon > Signed-off-by: Ron Minnich > Tested-by: Ron Minnich > --- > drivers/mtd/parsers/cmdlinepart.c | 23 ++++++++++++++++++++--- > 1 file changed, 20 insertions(+), 3 deletions(-) This change broke OpenWrt booting on some IPQ40xx devices. Here for example the parts of the cmdline which the u-boot on an OpenMesh A62 sets automatically: root=31:11 mtdparts=spi0.0:256k(0:SBL1),128k(0:MIBIB),384k(0:QSEE),64k(0:CDT),64k(0:DDRPARAMS),64k(0:APPSBLENV),512k(0:APPSBL),64k(0:ART),64k(custom),64k(0:KEYS),0x002b0000(kernel),0x00c80000(rootfs),15552k(inactive) rootfsname=rootfs rootwait This is then parsed by newpart as: KEYS),0x002b0000(kernel),0x00c80000(rootfs),15552k(inactive) And of course, this results in: mtd: partition has size 0 [...] /dev/root: Can't open blockdev VFS: Cannot open root device "31:11" or unknown-block(31,11): error -6 Please append a correct "root=" boot option; here are the available partitions: 1f00 32768 mtdblock0 (driver?) Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,11) CPU1: stopping CPU: 1 PID: 0 Comm: This affects OpenWrt since the commit d6a9a92e3217 ("kernel: bump 5.4 to 5.4.69") because this change was backported to Linux v5.4.69. Reverting this change fixes the problem for me. And if I see it correctly, this is also affecting the kernel (4.14) for the OpenWrt 18.06.x + 19.07.x branch because it can also be found in there as part of the v4.14.200 release. Another workaround is to replace the first "(" with a NULL too. See the attached patch for the one which I used to fix the OpenWrt bootup. Kind regards, Sven