generic: 6.1: sync mt7530 DSA driver with upstream

Backport lots upstream changes, many of them fixes, for the mt7530 DSA
driver. Some of them may or may not find they way into Linux 6.1
stable, some certainly won't because they are fixes for backported
commits which aren't even present in Linux 6.1 upstream.

Apart from adding new patches, also remove mutated patch
723-net-mt7531-ensure-all-MACs-are-powered-down-before-r.patch
which should never have been added for Linux 6.1 -- it was applied
already upstream but coincidentally would fuzzy-apply in the wrong
place as well (for MT7530 instead of MT7531). While that didn't really
hurt anyone it is just unneeded.

The other deleted patch
795-mt7530-register-OF-node-for-internal-MDIO-bus.patch
has been replaced by an equivalent commit with a more complete patch
description by upstream maintainer Arınç Ünal.

The remaining differences compared to the upstream driver are:
 * C22/C45 MDIO ops aren't split
   Upstream did that, backporting it would require making changes to
   *all* DSA drivers
 * 'slave' -> 'user', 'master' -> 'conduit' language change in DSA
 * support for selecting preferred CPU port on MT7531
   Also this would require too many DSA framework changes potentially
   affecting other devices. If we ever really use Linux 6.1 in a
   release (I hope not) we can still reconsider to make the effort to
   backport that.

In addition to some minor bug fixes and style improvements the switch
should now behave more conformant when it comes to link-local frames,
and we will again be able to cleanly pick patches from upstream.

MAINTAIERS NOTE:
Three patches are already part of Linux stable and should be removed with
the next minor kernel version bump:
789-STABLE-01-net-dsa-mt7530-prevent-possible-incorrect-XTAL-frequ.patch
789-STABLE-02-net-dsa-mt7530-fix-link-local-frames-that-ingress-vl.patch
789-STABLE-03-net-dsa-mt7530-fix-handling-of-all-link-local-frames.patch

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

1 files changed, 40 insertions, 0 deletions

diff --git a/target/linux/generic/backport-6.1/790-20-v6.7-net-dsa-mt7530-replace-deprecated-strncpy-with-ethto.patch b/target/linux/generic/backport-6.1/790-20-v6.7-net-dsa-mt7530-replace-deprecated-strncpy-with-ethto.patch
new file mode 100644
index 0000000000..e8fec3f6a1
--- /dev/null
+++ b/target/linux/generic/backport-6.1/790-20-v6.7-net-dsa-mt7530-replace-deprecated-strncpy-with-ethto.patch
@@ -0,0 +1,40 @@
+From 51e9c79a4d40fa3a64c0fbdab1ebbebf7cce2dba Mon Sep 17 00:00:00 2001
+From: Justin Stitt <justinstitt@google.com>
+Date: Mon, 9 Oct 2023 18:29:19 +0000
+Subject: [PATCH 20/48] net: dsa: mt7530: replace deprecated strncpy with
+ ethtool_sprintf
+
+`strncpy` is deprecated for use on NUL-terminated destination strings
+[1] and as such we should prefer more robust and less ambiguous string
+interfaces.
+
+ethtool_sprintf() is designed specifically for get_strings() usage.
+Let's replace strncpy in favor of this more robust and easier to
+understand interface.
+
+Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
+Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
+Link: https://github.com/KSPP/linux/issues/90
+Signed-off-by: Justin Stitt <justinstitt@google.com>
+Reviewed-by: Kees Cook <keescook@chromium.org>
+Acked-by: Daniel Golle <daniel@makrotopia.org>
+Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
+Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
+Link: https://lore.kernel.org/r/20231009-strncpy-drivers-net-dsa-mt7530-c-v1-1-ec6677a6436a@google.com
+Signed-off-by: Jakub Kicinski <kuba@kernel.org>
+---
+ drivers/net/dsa/mt7530.c | 3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+--- a/drivers/net/dsa/mt7530.c
++++ b/drivers/net/dsa/mt7530.c
+@@ -829,8 +829,7 @@ mt7530_get_strings(struct dsa_switch *ds
+ 		return;
+ 
+ 	for (i = 0; i < ARRAY_SIZE(mt7530_mib); i++)
+-		strncpy(data + i * ETH_GSTRING_LEN, mt7530_mib[i].name,
+-			ETH_GSTRING_LEN);
++		ethtool_sprintf(&data, "%s", mt7530_mib[i].name);
+ }
+ 
+ static void