On 10/15/2014 02:32 PM, Jingchang Lu wrote:
-----Original Message-----
From: Joseph Lo [mailto:josephl@xxxxxxxxxx]
Sent: Wednesday, October 15, 2014 9:01 AM
To: Lu Jingchang-B35083; gregkh@xxxxxxxxxxxxxxxxxxx
Cc: peter@xxxxxxxxxxxxxxxxxx; arnd@xxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
linux-serial@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Subject: Re: [PATCHv4] serial: of-serial: fix up PM ops on
no_console_suspend and port type
On 10/14/2014 04:42 PM, Jingchang Lu wrote:
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.
Signed-off-by: Jingchang Lu <jingchang.lu@xxxxxxxxxxxxx>
If you can make sure this patch can build without include
<linux/console.h>, then this patch
The build passes on my cloned linux-next tree, include next-20141014,
but is required on my another kernel-3.12+ based tree, then I didn't
add this header file when upstream.
Is the build broken on your source tree, and is the tree latest?
If the header is needed, I will add it.
I tested it on next-20141013 and k3.14, both of them need the fix. I can
check it again against the latest linux-next tree later. Thanks.
-Joseph
Thanks.
Best Regards,
Jingchang
Tested-by: Joseph Lo <josephl@xxxxxxxxxx>
And thanks for your fix.
---
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 | 52
++++++++++++++++++++++++++++++++++++------
1 file changed, 45 insertions(+), 7 deletions(-)
diff --git a/drivers/tty/serial/of_serial.c
b/drivers/tty/serial/of_serial.c index 8bc2563..5281f8f 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -241,13 +241,48 @@ 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 +291,13 @@ 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;
}
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