Hi,
We observed the following sporadic boot failure while booting from MMC device:
=> boot CACHE: Misaligned operation at range [9efa25f8, 9efa27f8] CACHE: Misaligned operation at range [9efa25f8, 9efa27f8] CACHE: Misaligned operation at range [9efa25f8, 9efa27f8] CACHE: Misaligned operation at range [9efa25f8, 9efa27f8] ** Booting bootflow 'mmc@2194000.bootdev.part_1' with extlinux Ignoring unknown command: �D���D�� Boot failed (err=-14)
The reason is because while allocating buffer to read a file from MMC, alignment of 1 byte is used. Thus, the buffer doesn't work for performing DMA, and garbage data is read.
While looking at this issue, I also noticed that if no alignment specified (align=0) then fs_read_alloc() is documented to use the default. But the default is no alignment. Therefore, other users of fs_read_alloc() which specify align=0 may be broken as well.
The first patch changes the default to align the buffer suitable for DMA.
The second patch changes extlinux_read_bootflow() to use the default alignment.
Nam Cao (2): fs: Use ARCH_DMA_MINALIGN as default alignment for fs_read_alloc() boot: extlinux: Fix unaligned buffer for reading data from file system
boot/bootmeth_extlinux.c | 2 +- fs/fs.c | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-)