Hi,
This patch might have a potential issue that cause system hard hung
immediately when it accesses to registers with no clock. This could
happen on many chips that mainline kernel supporting with the setting
"no_console_suspend=1" during suspend time.
On 09/23/2014 04:34 PM, Jingchang Lu wrote:
This adds PM suspend/resume support for the of-serial driver
to provide power management support on devices attatched to it.
Signed-off-by: Jingchang Lu <jingchang.lu@xxxxxxxxxxxxx>
---
drivers/tty/serial/of_serial.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 27981e2..8bc2563 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -240,6 +240,32 @@ static int of_platform_serial_remove(struct platform_device *ofdev)
return 0;
}
+#ifdef CONFIG_PM_SLEEP
+static int of_serial_suspend(struct device *dev)
+{
+ struct of_serial_info *info = dev_get_drvdata(dev);
+
+ serial8250_suspend_port(info->line);
+ if (info->clk)
The fix would be something like this.
if (info->clk && console_suspend_enabled)
+ clk_disable_unprepare(info->clk);
+
+ return 0;
+}
+
+static int of_serial_resume(struct device *dev)
+{
+ struct of_serial_info *info = dev_get_drvdata(dev);
+
+ if (info->clk)
Ditto.
Thanks,
-Joseph
+ clk_prepare_enable(info->clk);
+
+ serial8250_resume_port(info->line);
+
+ return 0;
+}
+#endif
+static SIMPLE_DEV_PM_OPS(of_serial_pm_ops, of_serial_suspend, of_serial_resume);
+
/*
* A few common types, add more as needed.
*/
@@ -271,6 +297,7 @@ static struct platform_driver of_platform_serial_driver = {
.name = "of_serial",
.owner = THIS_MODULE,
.of_match_table = of_platform_serial_table,
+ .pm = &of_serial_pm_ops,
},
.probe = of_platform_serial_probe,
.remove = of_platform_serial_remove,
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