Hi Mario,
On 5 March 2018 at 23:54, Mario Six mario.six@gdsys.cc wrote:
Commit 286ede6 ("drivers: core: Add translation in live tree case") made dev_get_addr always use proper bus translations for addresses read from the device tree. But this leads to problems with certain busses, e.g. I2C busses, which run into an error during translation, and hence stop working.
It turns out that of_translate_address() and fdt_translate_address() stop the address translation with an error when they're asked to translate addresses for busses where #size-cells == 0 (comment from drivers/core/of_addr.c):
- Note: We consider that crossing any level with #size-cells == 0 to mean
- that translation is impossible (that is we are not dealing with a value
- that can be mapped to a cpu physical address). This is not really specified
- that way, but this is traditionally the way IBM at least do things
To fix this case, we check in both the live-tree and non-live tree-case, whether the bus of the device whose address is about to be translated has size-cell size zero. If this is the case, we just read the address as a plain integer and return it, and only apply bus translations if the size-cell size if greater than zero.
Signed-off-by: Mario Six mario.six@gdsys.cc Signed-off-by: Martin Fuzzey mfuzzey@parkeon.com Reported-by: Martin Fuzzey mfuzzey@parkeon.com Fixes: 286ede6 ("drivers: core: Add translation in live tree case")
drivers/core/fdtaddr.c | 17 +++++++++++------ drivers/core/ofnode.c | 5 ++++- 2 files changed, 15 insertions(+), 7 deletions(-)
This looks right to me, but I really think we need to create a simple test for it. Perhaps call this function in test/dm/test-fdt.c for a few cases? You can add whatever you like to test.dts.
Regards, Simon