[xen master] arm/duart: make dt_uart_init() compile with -Wwrite-strings

[patchbot@xxxxxxx]

commit 6c1d5f65162fec80c53c2f782e0546e9e5b98e7c
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Mon Nov 20 21:33:10 2023 +0000
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Tue Nov 21 13:28:51 2023 +0000

    arm/duart: make dt_uart_init() compile with -Wwrite-strings
    
    GCC complains:
    
      drivers/char/arm-uart.c: In function 'dt_uart_init':
      drivers/char/arm-uart.c:81:17: error: assignment discards 'const' 
qualifier from pointer target type [-Werror=discarded-qualifiers]
         81 |         options = "";
            |                 ^
    
    The problem is using the options string for both splitting opt_duart, and to
    hold a token "" for no options.
    
    Use two variables; one mutable and one const.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 xen/drivers/char/arm-uart.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/xen/drivers/char/arm-uart.c b/xen/drivers/char/arm-uart.c
index 8098a968c2..91f13a4136 100644
--- a/xen/drivers/char/arm-uart.c
+++ b/xen/drivers/char/arm-uart.c
@@ -42,7 +42,8 @@ static void __init dt_uart_init(void)
     struct dt_device_node *dev;
     int ret;
     const char *devpath = opt_dtuart;
-    char *options;
+    const char *options;
+    char *split;
 
     if ( !console_has("dtuart") )
         return; /* Not for us */
@@ -74,9 +75,12 @@ static void __init dt_uart_init(void)
         return;
     }
 
-    options = strchr(opt_dtuart, ':');
-    if ( options != NULL )
-        *(options++) = '\0';
+    split = strchr(opt_dtuart, ':');
+    if ( split )
+    {
+        split[0] = '\0';
+        options = split + 1;
+    }
     else
         options = "";
 
--
generated by git-patchbot for /home/xen/git/xen.git#master