[i2c-mxs] Broken DMA operations from within a module

Russell King - ARM Linux [off-list ref] writes:

quoted

               .buf = "something",
...
random data will be sent because buf is not DMA mapable ("something" is
located in the .strtab section within module memory). MXS has a memory
layout like

DMA buffers must be located in lowmem *always*.  This means placing them
in the .data segment does not work.  USB has been through this already
and it's well known there...

Yes; I know about USB and this requirement is explicitly mentioned in
the 'struct urb' documentation.  But I can not find something similar
for i2c_msg and lot of i2c drivers are working with non DMA mapable
buffers.


Enrico