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tty: serial: 8250: Fix another runtime PM usage counter underflow

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BugLink: https://bugs.launchpad.net/bugs/2106770

commit ed2761958ad77e54791802b07095786150eab844 upstream.

The commit f9b11229b7 ("serial: 8250: Fix PM usage_count for console
handover") fixed one runtime PM usage counter balance problem that
occurs because .dev is not set during univ8250 setup preventing call to
pm_runtime_get_sync(). Later, univ8250_console_exit() will trigger the
runtime PM usage counter underflow as .dev is already set at that time.

Call pm_runtime_get_sync() to balance the RPM usage counter also in
serial8250_register_8250_port() before trying to add the port.

Reported-by: Borislav Petkov (AMD) <bp@alien8.de>
Fixes: bedb404e91 ("serial: 8250_port: Don't use power management for kernel console")
Cc: stable <stable@kernel.org>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20241210170120.2231-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Manuel Diewald <manuel.diewald@canonical.com>
Signed-off-by: Mehmet Basaran <mehmet.basaran@canonical.com>
This commit is contained in:
Ilpo Järvinen
2024-12-10 19:01:20 +02:00
committed by Mehmet Basaran
parent af9cf4a8a1
commit a6afd0140b
1 changed files with 3 additions and 0 deletions
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drivers/tty/serial/8250/8250_core.c
+3
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@@ -1130,6 +1130,9 @@ int serial8250_register_8250_port(const struct uart_8250_port *up)
uart->dl_write = up->dl_write;
if (uart->port.type != PORT_8250_CIR) {
if (uart_console_registered(&uart->port))
pm_runtime_get_sync(uart->port.dev);
if (serial8250_isa_config != NULL)
serial8250_isa_config(0, &uart->port,
&uart->capabilities);