This patch fixes commit 2dea53bf57783f243c892e99c10c6921e956aa7e,
"serial: of-serial: add PM suspend/resume support", which disables
the uart clock on suspend, but also causes a hardware hang on register
access if no_console_suspend command line option is used.
Also, not every of_serial device is an 8250 port, so the serial8250
suspend/resume functions should only be applied to a real 8250 port.
Reported-by: Joseph Lo <[email protected]>
Signed-off-by: Jingchang Lu <[email protected]>
Tested-by: Joseph Lo <[email protected]>
Reviewed-by: Peter Hurley <[email protected]>
---
changes in v5:
add missing <linux/console.h> include.
changes in v4:
separate 8250 port suspend/resume from of_serial_suspend/resume.
changes in v3:
fix up point reference and deference.
changes in v2:
add switch selection on uart type.
drivers/tty/serial/of_serial.c | 53 ++++++++++++++++++++++++++++++++++++------
1 file changed, 46 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 8bc2563..9c64ad2 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -9,6 +9,7 @@
* 2 of the License, or (at your option) any later version.
*
*/
+#include <linux/console.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/delay.h>
@@ -241,13 +242,48 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
}
#ifdef CONFIG_PM_SLEEP
-static int of_serial_suspend(struct device *dev)
+#ifdef CONFIG_SERIAL_8250
+static void of_serial_suspend_8250(struct of_serial_info *info)
{
- struct of_serial_info *info = dev_get_drvdata(dev);
+ struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+ struct uart_port *port = &port8250->port;
serial8250_suspend_port(info->line);
- if (info->clk)
+ if (info->clk && (!uart_console(port) || console_suspend_enabled))
clk_disable_unprepare(info->clk);
+}
+
+static void of_serial_resume_8250(struct of_serial_info *info)
+{
+ struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+ struct uart_port *port = &port8250->port;
+
+ if (info->clk && (!uart_console(port) || console_suspend_enabled))
+ clk_prepare_enable(info->clk);
+
+ serial8250_resume_port(info->line);
+}
+#else
+static inline void of_serial_suspend_8250(struct of_serial_info *info)
+{
+}
+
+static inline void of_serial_resume_8250(struct of_serial_info *info)
+{
+}
+#endif
+
+static int of_serial_suspend(struct device *dev)
+{
+ struct of_serial_info *info = dev_get_drvdata(dev);
+
+ switch(info->type) {
+ case PORT_8250 ... PORT_MAX_8250:
+ of_serial_suspend_8250(info);
+ break;
+ default:
+ break;
+ }
return 0;
}
@@ -256,10 +292,13 @@ static int of_serial_resume(struct device *dev)
{
struct of_serial_info *info = dev_get_drvdata(dev);
- if (info->clk)
- clk_prepare_enable(info->clk);
-
- serial8250_resume_port(info->line);
+ switch(info->type) {
+ case PORT_8250 ... PORT_MAX_8250:
+ of_serial_resume_8250(info);
+ break;
+ default:
+ break;
+ }
return 0;
}
--
1.8.0