[xen stable-4.20] xen/uart: report an error if the device type is not supported

[patchbot@xxxxxxx]

commit ce40b0be7a712ae0079a43ab481b1bc91ba8a34d
Author:     Roger Pau Monné <roger.pau@xxxxxxxxxx>
AuthorDate: Mon Apr 20 12:33:55 2026 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon Apr 20 12:33:55 2026 +0200

    xen/uart: report an error if the device type is not supported
    
    When using key pairs for the uart configuration (com1 and com2 command line
    options), report an error if the passed device=<type> is not recognized
    instead of silently ignoring it.
    
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    master commit: 550ee7c198010c297d74b69e07d95a26358eadbd
    master date: 2026-03-27 14:52:40 +0100
---
 xen/drivers/char/ns16550.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
index eaeb0e09d0..77acc188d9 100644
--- a/xen/drivers/char/ns16550.c
+++ b/xen/drivers/char/ns16550.c
@@ -1656,6 +1656,8 @@ static bool __init parse_namevalue_pairs(char *str, 
struct ns16550 *uart)
                 pci_uart_config(uart, 0, uart - ns16550_com);
                 dev_set = true;
             }
+            else
+                PARSE_ERR_RET("Unknown device type %s\n", param_value);
             break;
 
         case port_bdf:
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.20