* [PATCH] serial: of-serial: fix up PM ops on no_console_suspend @ 2014-10-09 9:10 Jingchang Lu 2014-10-10 5:04 ` Stephen Warren 2014-10-10 11:39 ` Peter Hurley 0 siblings, 2 replies; 6+ messages in thread From: Jingchang Lu @ 2014-10-09 9:10 UTC (permalink / raw) To: gregkh Cc: arnd, linux-serial, linux-arm-kernel, linux-kernel, Jingchang Lu, Joseph Lo Mandatorily disabling the uart clock will cause register access hung on "no_console_suspend". This patch add condition check on it and only disable the clock with console_suspend_enabled true. Signed-off-by: Joseph Lo <josephl@nvidia.com> Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com> --- drivers/tty/serial/of_serial.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c index 8bc2563..a765399 100644 --- a/drivers/tty/serial/of_serial.c +++ b/drivers/tty/serial/of_serial.c @@ -246,7 +246,7 @@ 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) + if (info->clk && console_suspend_enabled) clk_disable_unprepare(info->clk); return 0; @@ -256,7 +256,7 @@ static int of_serial_resume(struct device *dev) { struct of_serial_info *info = dev_get_drvdata(dev); - if (info->clk) + if (info->clk && console_suspend_enabled) clk_prepare_enable(info->clk); serial8250_resume_port(info->line); -- 1.8.0 ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] serial: of-serial: fix up PM ops on no_console_suspend 2014-10-09 9:10 [PATCH] serial: of-serial: fix up PM ops on no_console_suspend Jingchang Lu @ 2014-10-10 5:04 ` Stephen Warren 2014-10-10 6:16 ` Jingchang Lu 2014-10-10 11:39 ` Peter Hurley 1 sibling, 1 reply; 6+ messages in thread From: Stephen Warren @ 2014-10-10 5:04 UTC (permalink / raw) To: Jingchang Lu, gregkh Cc: arnd, Joseph Lo, linux-kernel, linux-serial, linux-arm-kernel On 10/09/2014 02:10 AM, Jingchang Lu wrote: > Mandatorily disabling the uart clock will cause register access > hung on "no_console_suspend". This patch add condition check on > it and only disable the clock with console_suspend_enabled true. It would be useful if the email/patch subject line said "V2", and there was a changelog below. > Signed-off-by: Joseph Lo <josephl@nvidia.com> I don't think he did; he just suggested a small fix. > Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com> > --- > drivers/tty/serial/of_serial.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c ... ^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH] serial: of-serial: fix up PM ops on no_console_suspend 2014-10-10 5:04 ` Stephen Warren @ 2014-10-10 6:16 ` Jingchang Lu 2014-10-10 10:25 ` Peter Hurley 0 siblings, 1 reply; 6+ messages in thread From: Jingchang Lu @ 2014-10-10 6:16 UTC (permalink / raw) To: Stephen Warren, gregkh@linuxfoundation.org Cc: arnd@arndb.de, Joseph Lo, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org [-- Warning: decoded text below may be mangled, UTF-8 assumed --] [-- Attachment #1: Type: text/plain; charset="utf-8", Size: 1119 bytes --] >-----Original Message----- >From: Stephen Warren [mailto:swarren@wwwdotorg.org] >Sent: Friday, October 10, 2014 1:05 PM >To: Lu Jingchang-B35083; gregkh@linuxfoundation.org >Cc: arnd@arndb.de; Joseph Lo; linux-kernel@vger.kernel.org; linux- >serial@vger.kernel.org; linux-arm-kernel@lists.infradead.org >Subject: Re: [PATCH] serial: of-serial: fix up PM ops on >no_console_suspend > >On 10/09/2014 02:10 AM, Jingchang Lu wrote: >> Mandatorily disabling the uart clock will cause register access hung >> on "no_console_suspend". This patch add condition check on it and only >> disable the clock with console_suspend_enabled true. > >It would be useful if the email/patch subject line said "V2", and there >was a changelog below. This is not a v2, patch "serial: of-serial: add PM suspend/resume support (commit 2dea53bf57783f243c892e99c10c6921e956aa7e)" has been merged into linux-next tree, this is a fixup on that PM ops. Thanks. Best Regards, Jingchang ÿôèº{.nÇ+‰·Ÿ®‰†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a¢f£¢·hšïêÿ‘êçz_è®\x03(階ŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨èÚ&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥ ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] serial: of-serial: fix up PM ops on no_console_suspend 2014-10-10 6:16 ` Jingchang Lu @ 2014-10-10 10:25 ` Peter Hurley 0 siblings, 0 replies; 6+ messages in thread From: Peter Hurley @ 2014-10-10 10:25 UTC (permalink / raw) To: Jingchang Lu, Stephen Warren, gregkh@linuxfoundation.org Cc: arnd@arndb.de, Joseph Lo, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org On 10/10/2014 02:16 AM, Jingchang Lu wrote: >> From: Stephen Warren [mailto:swarren@wwwdotorg.org] >> On 10/09/2014 02:10 AM, Jingchang Lu wrote: >>> Mandatorily disabling the uart clock will cause register access hung >>> on "no_console_suspend". This patch add condition check on it and only >>> disable the clock with console_suspend_enabled true. >> >> It would be useful if the email/patch subject line said "V2", and there >> was a changelog below. > This is not a v2, patch "serial: of-serial: add PM suspend/resume support > (commit 2dea53bf57783f243c892e99c10c6921e956aa7e)" has been merged into > linux-next tree, this is a fixup on that PM ops. Then please say so in the commit log. Something like, Fix 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. Regards, Peter Hurley ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] serial: of-serial: fix up PM ops on no_console_suspend 2014-10-09 9:10 [PATCH] serial: of-serial: fix up PM ops on no_console_suspend Jingchang Lu 2014-10-10 5:04 ` Stephen Warren @ 2014-10-10 11:39 ` Peter Hurley 2014-10-11 3:37 ` Jingchang Lu 1 sibling, 1 reply; 6+ messages in thread From: Peter Hurley @ 2014-10-10 11:39 UTC (permalink / raw) To: Jingchang Lu, gregkh Cc: arnd, linux-serial, linux-arm-kernel, linux-kernel, Joseph Lo Hi Jingchang, On 10/09/2014 05:10 AM, Jingchang Lu wrote: > Mandatorily disabling the uart clock will cause register access > hung on "no_console_suspend". This patch add condition check on > it and only disable the clock with console_suspend_enabled true. > > Signed-off-by: Joseph Lo <josephl@nvidia.com> > Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com> > --- > drivers/tty/serial/of_serial.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c > index 8bc2563..a765399 100644 > --- a/drivers/tty/serial/of_serial.c > +++ b/drivers/tty/serial/of_serial.c > @@ -246,7 +246,7 @@ 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) > + if (info->clk && console_suspend_enabled) > clk_disable_unprepare(info->clk); This needs to check that _this_ port is the console port, like: if (info->clk && uart_console(port) && and console_suspend_enabled) clk_disable_unprepare(info->clk); which means you need something like: struct uart_8250_port *uart = serial8250_get_port(info->line); struct uart_port *port = &uart->port; Also, there's another problem with your original patch: not every of_serial device is an 8250, right? serial8250_suspend_port() on a port that's not registered with 8250 core is probably going to blow up. Which means the body of of_platform_suspend() and of_platform_resume() should probably look like switch (info->type) { #ifdef CONFIG_SERIAL_8250 case PORT_8250 ... PORT_MAX_8250: { /* current body of function */ } #endif default: } Regards, Peter Hurley > > return 0; > @@ -256,7 +256,7 @@ static int of_serial_resume(struct device *dev) > { > struct of_serial_info *info = dev_get_drvdata(dev); > > - if (info->clk) > + if (info->clk && console_suspend_enabled) > clk_prepare_enable(info->clk); > > serial8250_resume_port(info->line); > ^ permalink raw reply [flat|nested] 6+ messages in thread
* RE: [PATCH] serial: of-serial: fix up PM ops on no_console_suspend 2014-10-10 11:39 ` Peter Hurley @ 2014-10-11 3:37 ` Jingchang Lu 0 siblings, 0 replies; 6+ messages in thread From: Jingchang Lu @ 2014-10-11 3:37 UTC (permalink / raw) To: Peter Hurley, gregkh@linuxfoundation.org Cc: arnd@arndb.de, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Joseph Lo [-- Warning: decoded text below may be mangled, UTF-8 assumed --] [-- Attachment #1: Type: text/plain; charset="utf-8", Size: 2787 bytes --] >-----Original Message----- >From: Peter Hurley [mailto:peter@hurleysoftware.com] >Sent: Friday, October 10, 2014 7:39 PM >To: Lu Jingchang-B35083; gregkh@linuxfoundation.org >Cc: arnd@arndb.de; linux-serial@vger.kernel.org; linux-arm- >kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Joseph Lo >Subject: Re: [PATCH] serial: of-serial: fix up PM ops on >no_console_suspend > >Hi Jingchang, > >On 10/09/2014 05:10 AM, Jingchang Lu wrote: >> Mandatorily disabling the uart clock will cause register access hung >> on "no_console_suspend". This patch add condition check on it and only >> disable the clock with console_suspend_enabled true. >> >> Signed-off-by: Joseph Lo <josephl@nvidia.com> >> Signed-off-by: Jingchang Lu <jingchang.lu@freescale.com> >> --- >> drivers/tty/serial/of_serial.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/tty/serial/of_serial.c >> b/drivers/tty/serial/of_serial.c index 8bc2563..a765399 100644 >> --- a/drivers/tty/serial/of_serial.c >> +++ b/drivers/tty/serial/of_serial.c >> @@ -246,7 +246,7 @@ 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) >> + if (info->clk && console_suspend_enabled) >> clk_disable_unprepare(info->clk); > >This needs to check that _this_ port is the console port, like: > > if (info->clk && uart_console(port) && and console_suspend_enabled) > clk_disable_unprepare(info->clk); > >which means you need something like: > > struct uart_8250_port *uart = serial8250_get_port(info->line); > struct uart_port *port = &uart->port; > >Also, there's another problem with your original patch: >not every of_serial device is an 8250, right? >serial8250_suspend_port() on a port that's not registered with 8250 core >is probably going to blow up. > >Which means the body of of_platform_suspend() and of_platform_resume() >should probably look like > > switch (info->type) { >#ifdef CONFIG_SERIAL_8250 > case PORT_8250 ... PORT_MAX_8250: > { > /* current body of function */ > } >#endif > default: > } > Yes, this should be considered, then serial8250_get_port(info->line) for uart_console() also should be put in this type switch, Thanks. Best Regards, Jingchang >Regards, >Peter Hurley > > >> >> return 0; >> @@ -256,7 +256,7 @@ static int of_serial_resume(struct device *dev) { >> struct of_serial_info *info = dev_get_drvdata(dev); >> >> - if (info->clk) >> + if (info->clk && console_suspend_enabled) >> clk_prepare_enable(info->clk); >> >> serial8250_resume_port(info->line); >> ÿôèº{.nÇ+‰·Ÿ®‰†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a¢f£¢·hšïêÿ‘êçz_è®\x03(階ŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨èÚ&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥ ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-10-11 3:37 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2014-10-09 9:10 [PATCH] serial: of-serial: fix up PM ops on no_console_suspend Jingchang Lu 2014-10-10 5:04 ` Stephen Warren 2014-10-10 6:16 ` Jingchang Lu 2014-10-10 10:25 ` Peter Hurley 2014-10-10 11:39 ` Peter Hurley 2014-10-11 3:37 ` Jingchang Lu
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