This is a note to let you know that I've just added the patch titled
of: address: Preserve the flags portion on 1:1 dma-ranges mapping
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
of-address-preserve-the-flags-portion-on-1-1-dma-ran.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ddef21a3f2ca63aa185b216767d52a9a0f63592f
Author: Andrea della Porta <andrea.porta@xxxxxxxx>
Date: Sun Nov 24 11:05:37 2024 +0100
of: address: Preserve the flags portion on 1:1 dma-ranges mapping
[ Upstream commit 7f05e20b989ac33c9c0f8c2028ec0a566493548f ]
A missing or empty dma-ranges in a DT node implies a 1:1 mapping for dma
translations. In this specific case, the current behaviour is to zero out
the entire specifier so that the translation could be carried on as an
offset from zero. This includes address specifier that has flags (e.g.
PCI ranges).
Once the flags portion has been zeroed, the translation chain is broken
since the mapping functions will check the upcoming address specifier
against mismatching flags, always failing the 1:1 mapping and its entire
purpose of always succeeding.
Set to zero only the address portion while passing the flags through.
Fixes: dbbdee94734b ("of/address: Merge all of the bus translation code")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Andrea della Porta <andrea.porta@xxxxxxxx>
Tested-by: Herve Codina <herve.codina@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/e51ae57874e58a9b349c35e2e877425ebc075d7a.1732441813.git.andrea.porta@xxxxxxxx
Signed-off-by: Rob Herring (Arm) <robh@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/of/address.c b/drivers/of/address.c
index cdefe5a89e5d..34d880a1be0a 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -476,7 +476,8 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
}
if (ranges == NULL || rlen == 0) {
offset = of_read_number(addr, na);
- memset(addr, 0, pna * 4);
+ /* set address to zero, pass flags through */
+ memset(addr + pbus->flag_cells, 0, (pna - pbus->flag_cells) * 4);
pr_debug("empty ranges; 1:1 translation\n");
goto finish;
}
