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>

0 files changed, 0 insertions, 0 deletions