[PATCHv3] serial: of-serial: fix up PM ops on no_console_suspend and port type
From: Peter Hurley <hidden>
Date: 2014-10-13 12:01:16
Also in:
linux-serial, lkml
On 10/13/2014 05:14 AM, Jingchang Lu wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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
quoted hunk ↗ jump to hunk
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; }