[PATCHv2] serial: of-serial: fix up PM ops on no_console_suspend and port type

Jingchang Lu jingchang.lu at freescale.com
Mon Oct 13 02:49:36 PDT 2014


My mistake, I will fix it, many thanks.

Best Regards,
Jingchang

>-----Original Message-----
>From: Joseph Lo [mailto:josephl at nvidia.com]
>Sent: Monday, October 13, 2014 5:41 PM
>To: Lu Jingchang-B35083; gregkh at linuxfoundation.org
>Cc: devicetree at vger.kernel.org; peter at hurleysoftware.com; arnd at arndb.de;
>linux-kernel at vger.kernel.org; linux-serial at vger.kernel.org; linux-arm-
>kernel at lists.infradead.org
>Subject: Re: [PATCHv2] serial: of-serial: fix up PM ops on
>no_console_suspend and port type
>
>Hi,
>
>On 10/13/2014 03:37 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 at freescale.com>
>> ---
>> changes in v2:
>>   add switch selection on uart type.
>
>After apply this, it can't build for me. I still need to apply the fix
>like something below.
>
>diff --git a/drivers/tty/serial/of_serial.c
>b/drivers/tty/serial/of_serial.c
>index e535f9c1563d..14c1ff4e7816 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>
>@@ -248,13 +249,13 @@ static int of_serial_suspend(struct device *dev)
>  #ifdef CONFIG_SERIAL_8250
>         case PORT_8250 ... PORT_MAX_8250:
>         {
>-               struct uart_8250_port port8250;
>+               struct uart_8250_port *port8250;
>                 port8250 = serial8250_get_port(info->line);
>
>                 serial8250_suspend_port(info->line);
>                 if (info->clk &&
>-                   (!uart_console(port8250) ||
>-                    (uart_console(port8250) && console_suspend_enabled)))
>+                   (!uart_console(&port8250->port) ||
>+                    (uart_console(&port8250->port) &&
>console_suspend_enabled)))
>                         clk_disable_unprepare(info->clk);
>                 break;
>         }
>@@ -274,12 +275,12 @@ static int of_serial_resume(struct device *dev)
>  #ifdef CONFIG_SERIAL_8250
>         case PORT_8250 ... PORT_MAX_8250:
>         {
>-               struct uart_8250_port port8250;
>+               struct uart_8250_port *port8250;
>                 port8250 = serial8250_get_port(info->line);
>
>                 if (info->clk &&
>-                   (!uart_console(port8250) ||
>-                    (uart_console(port8250) && console_suspend_enabled)))
>+                   (!uart_console(&port8250->port) ||
>+                    (uart_console(&port8250->port) &&
>console_suspend_enabled)))
>                         clk_prepare_enable(info->clk);
>
>                 serial8250_resume_port(info->line);
>
>-Joseph
>
>>
>>   drivers/tty/serial/of_serial.c | 42
>++++++++++++++++++++++++++++++++++++------
>>   1 file changed, 36 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/tty/serial/of_serial.c
>b/drivers/tty/serial/of_serial.c
>> index 8bc2563..b525383 100644
>> --- a/drivers/tty/serial/of_serial.c
>> +++ b/drivers/tty/serial/of_serial.c
>> @@ -245,9 +245,24 @@ 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)
>> -		clk_disable_unprepare(info->clk);
>> +	switch(info->type) {
>> +#ifdef CONFIG_SERIAL_8250
>> +	case PORT_8250 ... PORT_MAX_8250:
>> +	{
>> +		struct uart_8250_port port8250;
>> +		port8250 = serial8250_get_port(info->line);
>> +
>> +		serial8250_suspend_port(info->line);
>> +		if (info->clk &&
>> +		    (!uart_console(port8250) ||
>> +		     (uart_console(port8250) && console_suspend_enabled)))
>> +			clk_disable_unprepare(info->clk);
>> +		break;
>> +	}
>> +#endif
>> +	default:
>> +		break;
>> +	}
>>
>>   	return 0;
>>   }
>> @@ -256,10 +271,25 @@ 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);
>> +	switch(info->type) {
>> +#ifdef CONFIG_SERIAL_8250
>> +	case PORT_8250 ... PORT_MAX_8250:
>> +	{
>> +		struct uart_8250_port port8250;
>> +		port8250 = serial8250_get_port(info->line);
>> +
>> +		if (info->clk &&
>> +		    (!uart_console(port8250) ||
>> +		     (uart_console(port8250) && console_suspend_enabled)))
>> +			clk_prepare_enable(info->clk);
>>
>> -	serial8250_resume_port(info->line);
>> +		serial8250_resume_port(info->line);
>> +		break;
>> +	}
>> +#endif
>> +	default:
>> +		break;
>> +	}
>>
>>   	return 0;
>>   }
>>


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