ramips: add linux 5.15 support for mt7621

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 63 insertions, 0 deletions

diff --git a/target/linux/ramips/patches-5.15/314-MIPS-add-bootargs-override-property.patch b/target/linux/ramips/patches-5.15/314-MIPS-add-bootargs-override-property.patch
new file mode 100644
index 0000000000..07635a9d86
--- /dev/null
+++ b/target/linux/ramips/patches-5.15/314-MIPS-add-bootargs-override-property.patch
@@ -0,0 +1,63 @@
+From f15d27f9c90ede4b16eb37f9ae573ef81c2b6996 Mon Sep 17 00:00:00 2001
+From: David Bauer <mail@david-bauer.net>
+Date: Thu, 31 Dec 2020 18:49:12 +0100
+Subject: [PATCH] MIPS: add bootargs-override property
+
+Add support for the bootargs-override property to the chosen node
+similar to the one used on ipq806x or mpc85xx.
+
+This is necessary, as the U-Boot used on some boards, notably the
+Ubiquiti UniFi 6 Lite, overwrite the bootargs property of the chosen
+node leading to a kernel panic when loading OpenWrt.
+
+Signed-off-by: David Bauer <mail@david-bauer.net>
+---
+ arch/mips/kernel/setup.c | 30 ++++++++++++++++++++++++++++++
+ 1 file changed, 30 insertions(+)
+
+--- a/arch/mips/kernel/setup.c
++++ b/arch/mips/kernel/setup.c
+@@ -544,8 +544,28 @@ static int __init bootcmdline_scan_chose
+ 
+ #endif /* CONFIG_OF_EARLY_FLATTREE */
+ 
++static int __init bootcmdline_scan_chosen_override(unsigned long node, const char *uname,
++						   int depth, void *data)
++{
++	bool *dt_bootargs = data;
++	const char *p;
++	int l;
++
++	if (depth != 1 || !data || strcmp(uname, "chosen") != 0)
++		return 0;
++
++	p = of_get_flat_dt_prop(node, "bootargs-override", &l);
++	if (p != NULL && l > 0) {
++		strlcpy(boot_command_line, p, COMMAND_LINE_SIZE);
++		*dt_bootargs = true;
++	}
++
++	return 1;
++}
++
+ static void __init bootcmdline_init(void)
+ {
++	bool dt_bootargs_override = false;
+ 	bool dt_bootargs = false;
+ 
+ 	/*
+@@ -559,6 +579,14 @@ static void __init bootcmdline_init(void
+ 	}
+ 
+ 	/*
++	 * If bootargs-override in the chosen node is set, use this as the
++	 * command line
++	 */
++	of_scan_flat_dt(bootcmdline_scan_chosen_override, &dt_bootargs_override);
++	if (dt_bootargs_override)
++		return;
++
++	/*
+ 	 * If the user specified a built-in command line &
+ 	 * MIPS_CMDLINE_BUILTIN_EXTEND, then the built-in command line is
+ 	 * prepended to arguments from the bootloader or DT so we'll copy them