| Message ID | 1413191667-10949-1-git-send-email-jingchang.lu@freescale.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 10/13/2014 05:14 AM, 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@freescale.com> > --- > changes in v3: > fix up point reference and deference. > > changes in v2: > add switch selection on uart type. > > 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..9d747a7 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->port) || > + (uart_console(&port8250->port) && console_suspend_enabled))) This conditional is the same as if (info->clk && (!uart_console(&port8250->port) || console_suspend_enabled)) > + clk_disable_unprepare(info->clk); > + break; > + } > +#endif > + default: > + break; > + } I suggest you separate this into a separate function like: #ifdef CONFIG_SERIAL_8250 static void of_serial_suspend_8250(struct of_serial_info *info) { struct uart_8250_port *uart = serial_8250_get_port(info->line); struct uart_port *port = &uart->port; serial8250_suspend_port(info->line); if (info->clk && (!uart_console(port) || console_suspend_enabled)) clk_disable_unprepare(info->clk); } #else static inline void of_serial_suspend_8250(struct of_serial_info *info) { } #endif and call it like: 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; } return 0; } I did not build-test this, so you should. Regards, Peter Hurley > > 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->port) || > + (uart_console(&port8250->port) && console_suspend_enabled))) > + clk_prepare_enable(info->clk); > > - serial8250_resume_port(info->line); > + serial8250_resume_port(info->line); > + break; > + } > +#endif > + default: > + break; > + } > > return 0; > } >
diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c index 8bc2563..9d747a7 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->port) || + (uart_console(&port8250->port) && 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->port) || + (uart_console(&port8250->port) && console_suspend_enabled))) + clk_prepare_enable(info->clk); - serial8250_resume_port(info->line); + serial8250_resume_port(info->line); + break; + } +#endif + default: + break; + } return 0; }
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@freescale.com> --- changes in v3: fix up point reference and deference. changes in v2: add switch selection on uart type. drivers/tty/serial/of_serial.c | 42 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 36 insertions(+), 6 deletions(-)