diff options
| author | Fushuai Wang <wangfushuai@baidu.com> | 2026-05-22 18:10:42 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-07-10 14:40:45 +0200 |
| commit | d338ab1d90603f875c4f7ed223406535378173a5 (patch) | |
| tree | 96c5e71cfdf86b098810250c4458ffafb56c186d /drivers/tty/serial | |
| parent | 4d105880666ab7f7914a75716d3e95b0d8b879dc (diff) | |
| download | linux-next-d338ab1d90603f875c4f7ed223406535378173a5.tar.gz linux-next-d338ab1d90603f875c4f7ed223406535378173a5.zip | |
serial: 8250: Clear CON_PRINTBUFFER on port re-registration
When two PnP devices map to the same physical port, the serial8250 driver
removes and re-registers the console structure for the same port.
During re-registration, the console structure still has CON_PRINTBUFFER set
from the initial registration, which causes console_init_seq() to set
console->seq to syslog_seq. This results in re-printing the entire
system log buffer, which may lead to RCU stall on slow serial consoles.
Clear CON_PRINTBUFFER when re-registering a port to prevent duplicate
log printing.
Fixes: 835d844d1a28 ("8250_pnp: do pnp probe before legacy probe")
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
Link: https://patch.msgid.link/20260522101042.21976-1-fushuai.wang@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial')
| -rw-r--r-- | drivers/tty/serial/8250/8250_core.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index f49862d90eeb..c0e8a4efbdcc 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -720,8 +720,12 @@ int serial8250_register_8250_port(const struct uart_8250_port *up) /* Preserve specified console flow control. */ cons_flow = uart_cons_flow_enabled(&uart->port); - if (uart->port.dev) + if (uart->port.dev) { + if (uart_console(&uart->port)) + uart->port.cons->flags &= ~CON_PRINTBUFFER; + uart_remove_one_port(&serial8250_reg, &uart->port); + } uart->port.ctrl_id = up->port.ctrl_id; uart->port.port_id = up->port.port_id; |