FAILED: patch "[PATCH] of: address: Preserve the flags portion on 1:1 dma-ranges" failed to apply to 5.4-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 7f05e20b989ac33c9c0f8c2028ec0a566493548f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024122347-fiscally-slacks-e686@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7f05e20b989ac33c9c0f8c2028ec0a566493548f Mon Sep 17 00:00:00 2001
From: Andrea della Porta <andrea.porta@suse.com>
Date: Sun, 24 Nov 2024 11:05:37 +0100
Subject: [PATCH] of: address: Preserve the flags portion on 1:1 dma-ranges
 mapping

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@vger.kernel.org
Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
Tested-by: Herve Codina <herve.codina@bootlin.com>
Link: https://lore.kernel.org/r/e51ae57874e58a9b349c35e2e877425ebc075d7a.1732441813.git.andrea.porta@suse.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

diff --git a/drivers/of/address.c b/drivers/of/address.c
index c5b925ac469f..5b7ee3ed5296 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -459,7 +459,8 @@ static int of_translate_one(const struct device_node *parent, const struct of_bu
 	}
 	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;
 	}