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authorVijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>2022-06-07 21:52:44 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-06-10 14:30:41 +0300
commitcfab87c2c2715763dc7e43d9968bdaa01cde4bc3 (patch)
treeba9de1fdf2ace007227aad12aeec2c9003a94f8a /drivers/tty
parente74024b2eccbb784824a0f9feaeaaa3b47514b79 (diff)
downloadlinux-cfab87c2c2715763dc7e43d9968bdaa01cde4bc3.tar.xz
serial: core: Introduce callback for start_rx and do stop_rx in suspend only if this callback implementation is present.
In suspend sequence there is a need to perform stop_rx during suspend sequence to prevent any asynchronous data over rx line. However this can cause problem to drivers which dont do re-start_rx during set_termios. Add new callback start_rx and perform stop_rx only when implementation of start_rx is present. Also add call to start_rx in resume sequence so that drivers who come across this problem can make use of this framework. Fixes: c9d2325cdb92 ("serial: core: Do stop_rx in suspend path for console if console_suspend is disabled") Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com> Link: https://lore.kernel.org/r/1654627965-1461-2-git-send-email-quic_vnivarth@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/serial_core.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 9a85b41caa0a..338ebadfd44b 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -2214,11 +2214,12 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
/*
* Nothing to do if the console is not suspending
* except stop_rx to prevent any asynchronous data
- * over RX line. Re-start_rx, when required, is
- * done by set_termios in resume sequence
+ * over RX line. However ensure that we will be
+ * able to Re-start_rx later.
*/
if (!console_suspend_enabled && uart_console(uport)) {
- uport->ops->stop_rx(uport);
+ if (uport->ops->start_rx)
+ uport->ops->stop_rx(uport);
goto unlock;
}
@@ -2310,6 +2311,8 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
if (console_suspend_enabled)
uart_change_pm(state, UART_PM_STATE_ON);
uport->ops->set_termios(uport, &termios, NULL);
+ if (!console_suspend_enabled && uport->ops->start_rx)
+ uport->ops->start_rx(uport);
if (console_suspend_enabled)
console_start(uport->cons);
}