[PATCH] of/fdt: extend cmdline is not avail when kernel grub config ends with "--"

[hmy]

when boot_command_line = boot-command "--" CONFIG_CMDLINE,
parse_args() will exit and without parsing the contents of CONFIG_CMDLINE

Signed-off-by: hmy <huanglin@xxxxxxxxxxxxx>
---
 drivers/of/fdt.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index a8f5b6532165..5a289712c8fb 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1162,6 +1162,7 @@ int __init early_init_dt_scan_chosen(char *cmdline)
 	const char *p;
 	const void *rng_seed;
 	const void *fdt = initial_boot_params;
+	char  *q __maybe_unused;
 
 	node = fdt_path_offset(fdt, "/chosen");
 	if (node < 0)
@@ -1186,6 +1187,9 @@ int __init early_init_dt_scan_chosen(char *cmdline)
 	 */
 #ifdef CONFIG_CMDLINE
 #if defined(CONFIG_CMDLINE_EXTEND)
+	q = strstr(cmdline, "--");
+	if (q)
+		*q = '\0';
 	strlcat(cmdline, " ", COMMAND_LINE_SIZE);
 	strlcat(cmdline, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 #elif defined(CONFIG_CMDLINE_FORCE)
-- 
2.20.1