[PATCHv5] serial: of-serial: fix up PM ops on no_console_suspend and port type
From: Joseph Lo <hidden>
Date: 2014-10-15 09:04:32
Also in:
linux-devicetree, linux-serial, lkml
On 10/15/2014 02:19 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 <redacted> --- changes in v5: add missing <linux/console.h> include. changes in v4: separate 8250 port suspend/resume from of_serial_suspend/resume. changes in v3: fix up point reference and deference. changes in v2: add switch selection on uart type.
Hi Jingchang, Thanks for the fix. This patch Tested-by: Joseph Lo <redacted>
quoted hunk ↗ jump to hunk
drivers/tty/serial/of_serial.c | 53 ++++++++++++++++++++++++++++++++++++------ 1 file changed, 46 insertions(+), 7 deletions(-)diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c index 8bc2563..9c64ad2 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>@@ -241,13 +242,48 @@ static int of_platform_serial_remove(struct platform_device *ofdev) } #ifdef CONFIG_PM_SLEEP -static int of_serial_suspend(struct device *dev) +#ifdef CONFIG_SERIAL_8250 +static void of_serial_suspend_8250(struct of_serial_info *info) { - struct of_serial_info *info = dev_get_drvdata(dev); + struct uart_8250_port *port8250 = serial8250_get_port(info->line); + struct uart_port *port = &port8250->port; serial8250_suspend_port(info->line); - if (info->clk) + if (info->clk && (!uart_console(port) || console_suspend_enabled)) clk_disable_unprepare(info->clk); +} + +static void of_serial_resume_8250(struct of_serial_info *info) +{ + struct uart_8250_port *port8250 = serial8250_get_port(info->line); + struct uart_port *port = &port8250->port; + + if (info->clk && (!uart_console(port) || console_suspend_enabled)) + clk_prepare_enable(info->clk); + + serial8250_resume_port(info->line); +} +#else +static inline void of_serial_suspend_8250(struct of_serial_info *info) +{ +} + +static inline void of_serial_resume_8250(struct of_serial_info *info) +{ +} +#endif + +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; + default: + break; + } return 0; }@@ -256,10 +292,13 @@ 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); - - serial8250_resume_port(info->line); + switch(info->type) { + case PORT_8250 ... PORT_MAX_8250: + of_serial_resume_8250(info); + break; + default: + break; + } return 0; }