Messages in this thread Patch in this message |  | | Date | Fri, 10 Oct 2014 07:39:21 -0400 | From | Peter Hurley <> | Subject | Re: [PATCH] serial: of-serial: fix up PM ops on no_console_suspend |
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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); >
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