From 5e227ef2aa388f14ceeafa65eb8a38fa37918eb4 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Thu, 16 Mar 2023 13:20:56 -0700 Subject: [PATCH] serial: uart_poll_init() should power on the UART On Qualcomm devices which use the "geni" serial driver, kdb/kgdb won't be very happy if you use it but the resources of the port haven't been powered on. Today kdb/kgdb rely on someone else powering the port on. This could be the normal kernel console or an agetty running. Let's fix this to explicitly power things on when setting up a polling driver. Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20230316132027.RESEND.1.I106c39498d8094c6f5e7ada42c7db17aa5c64e48@changeid Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/serial_core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index db7f6c0..afafbb7 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2590,6 +2590,7 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options) { struct uart_driver *drv = driver->driver_state; struct uart_state *state = drv->state + line; + enum uart_pm_state pm_state; struct tty_port *tport; struct uart_port *port; int baud = 9600; @@ -2607,6 +2608,9 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options) goto out; } + pm_state = state->pm_state; + uart_change_pm(state, UART_PM_STATE_ON); + if (port->ops->poll_init) { /* * We don't set initialized as we only initialized the hw, @@ -2623,6 +2627,8 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options) console_list_unlock(); } out: + if (ret) + uart_change_pm(state, pm_state); mutex_unlock(&tport->mutex); return ret; } -- 2.7.4