diff mbox

[RESENDv5] serial: of-serial: fix up PM ops on no_console_suspend and port type

Message ID 1414401857-21121-1-git-send-email-jingchang.lu@freescale.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jingchang Lu Oct. 27, 2014, 9:24 a.m. UTC
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 <josephl@nvidia.com>
Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
Tested-By: Joseph Lo <josephl@nvidia.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
---
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(-)

Comments

Florian Fainelli Nov. 11, 2014, 4:30 a.m. UTC | #1
2014-10-27 2:24 GMT-07:00 Jingchang Lu <jingchang.lu@freescale.com>:
> 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.

Greg, can you pick this one and submit it for your next 3.18-rc
submission? This fixes a regression when using "no_console_suspend"
introduced by:

2dea53bf57783f243c892e99c10c6921e956aa7e ("serial: of-serial: add PM
suspend/resume support") which has been merged during 3.18-rc1

Thanks!

>
> Reported-By: Joseph Lo <josephl@nvidia.com>
> Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com>
> Tested-By: Joseph Lo <josephl@nvidia.com>
> Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
> ---
> 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
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Greg KH Nov. 11, 2014, 5:27 a.m. UTC | #2
On Mon, Nov 10, 2014 at 08:30:36PM -0800, Florian Fainelli wrote:
> 2014-10-27 2:24 GMT-07:00 Jingchang Lu <jingchang.lu@freescale.com>:
> > 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.
> 
> Greg, can you pick this one and submit it for your next 3.18-rc
> submission? This fixes a regression when using "no_console_suspend"
> introduced by:
> 
> 2dea53bf57783f243c892e99c10c6921e956aa7e ("serial: of-serial: add PM
> suspend/resume support") which has been merged during 3.18-rc1

Why can't I just revert that patch instead?  This is really late in the
-rc cycle to be doing large fixes like this.

And this patch is already queued up for 3.19-rc1, so this is a mess...

Any objection to me just reverting
2dea53bf57783f243c892e99c10c6921e956aa7e, and then this one in my
tty-next branch as well, and then someone resending the original patch
in a format that actually works?

thanks,

greg k-h
Jingchang Lu Nov. 11, 2014, 5:41 a.m. UTC | #3
>-----Original Message-----
>From: Greg KH [mailto:gregkh@linuxfoundation.org]
>Sent: Tuesday, November 11, 2014 1:27 PM
>To: Florian Fainelli
>Cc: Lu Jingchang-B35083; linux-arm-kernel@lists.infradead.org; linux-
>kernel@vger.kernel.org; linux-serial@vger.kernel.org
>Subject: Re: [RESENDv5] serial: of-serial: fix up PM ops on
>no_console_suspend and port type
>
>On Mon, Nov 10, 2014 at 08:30:36PM -0800, Florian Fainelli wrote:
>> 2014-10-27 2:24 GMT-07:00 Jingchang Lu <jingchang.lu@freescale.com>:
>> > 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.
>>
>> Greg, can you pick this one and submit it for your next 3.18-rc
>> submission? This fixes a regression when using "no_console_suspend"
>> introduced by:
>>
>> 2dea53bf57783f243c892e99c10c6921e956aa7e ("serial: of-serial: add PM
>> suspend/resume support") which has been merged during 3.18-rc1
>
>Why can't I just revert that patch instead?  This is really late in the -
>rc cycle to be doing large fixes like this.
>
>And this patch is already queued up for 3.19-rc1, so this is a mess...
>
>Any objection to me just reverting
>2dea53bf57783f243c892e99c10c6921e956aa7e, and then this one in my tty-next
>branch as well, and then someone resending the original patch in a format
>that actually works?
Do you mean resending the "serial: of-serial: add PM suspend/resume support"
patch with "serial: of-serial: fix up PM ops on no_console_suspend and port type"
merged together? For you would like to reverting the previous patch of
"2dea53bf57783f243c892e99c10c6921e956aa7e".

Thanks and Best Regards,
Jingchang
>
>thanks,
>
>greg k-h
Florian Fainelli Nov. 11, 2014, 6:15 a.m. UTC | #4
2014-11-10 21:41 GMT-08:00 Jingchang Lu <jingchang.lu@freescale.com>:
>
>
>>-----Original Message-----
>>From: Greg KH [mailto:gregkh@linuxfoundation.org]
>>Sent: Tuesday, November 11, 2014 1:27 PM
>>To: Florian Fainelli
>>Cc: Lu Jingchang-B35083; linux-arm-kernel@lists.infradead.org; linux-
>>kernel@vger.kernel.org; linux-serial@vger.kernel.org
>>Subject: Re: [RESENDv5] serial: of-serial: fix up PM ops on
>>no_console_suspend and port type
>>
>>On Mon, Nov 10, 2014 at 08:30:36PM -0800, Florian Fainelli wrote:
>>> 2014-10-27 2:24 GMT-07:00 Jingchang Lu <jingchang.lu@freescale.com>:
>>> > 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.
>>>
>>> Greg, can you pick this one and submit it for your next 3.18-rc
>>> submission? This fixes a regression when using "no_console_suspend"
>>> introduced by:
>>>
>>> 2dea53bf57783f243c892e99c10c6921e956aa7e ("serial: of-serial: add PM
>>> suspend/resume support") which has been merged during 3.18-rc1
>>
>>Why can't I just revert that patch instead?  This is really late in the -
>>rc cycle to be doing large fixes like this.
>>
>>And this patch is already queued up for 3.19-rc1, so this is a mess...
>>
>>Any objection to me just reverting
>>2dea53bf57783f243c892e99c10c6921e956aa7e, and then this one in my tty-next
>>branch as well, and then someone resending the original patch in a format
>>that actually works?
> Do you mean resending the "serial: of-serial: add PM suspend/resume support"
> patch with "serial: of-serial: fix up PM ops on no_console_suspend and port type"
> merged together? For you would like to reverting the previous patch of
> "2dea53bf57783f243c892e99c10c6921e956aa7e".

That is how I understand Greg's suggestion. While you are at it you
might want to introduce a space between the 'switch' keyword and the
open-parenthesis in the two call sites that you added. Feel free to
add my:

Tested-by: Florina Fainelli <f.fainelli@gmail.com>

since I use your v5 patch locally, thanks!
--
Florian
diff mbox

Patch

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;
 }