Re: [PATCH v3 11/12] OMAP2: Serial: Add has_async_wake flag.

[Kevin Hilman <khilman@ti.com>]

"Govindraj.R" <govindraj.raja@ti.com> writes:

> Prior to this patch the uart_clock was cut using prepare/resume calls since
> these funcs are no more available with runtime changes use has_async_wake
> flag to keep clock active during bootup otherwise uart port will disabled
> during boot-up and cannot be enabled back.  

Is this only a bootup issue, or a runtime PM issue?  It appears to me
that with this patch, runtime PM is effectively disabled for the whole
time.

Why not just use pm_runtime_disable() in _probe() for devices with no
async wakeup.

> Also based on this flag we can disable uart port during suspend and
> enable back during resume for omap_socs that have not set
> has_async_wake.

Then you can use pm_runtime_enable() in ->prepare() and
pm_runtime_disable() in ->complete()

Kevin

> Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
> ---
>  arch/arm/mach-omap2/serial.c                  |    1 +
>  arch/arm/plat-omap/include/plat/omap-serial.h |    3 +++
>  drivers/tty/serial/omap-serial.c              |   14 ++++++++++++++
>  3 files changed, 18 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
> index 4bc5914..0a95c95 100644
> --- a/arch/arm/mach-omap2/serial.c
> +++ b/arch/arm/mach-omap2/serial.c
> @@ -266,6 +266,7 @@ static void omap_uart_idle_init(struct omap_uart_port_info *uart,
>  			break;
>  		}
>  		uart->wk_mask = wk_mask;
> +		uart->has_async_wake = true;
>  	} else if (cpu_is_omap24xx()) {
>  		u32 wk_mask = 0;
>  		u32 wk_en = PM_WKEN1, wk_st = PM_WKST1;
> diff --git a/arch/arm/plat-omap/include/plat/omap-serial.h b/arch/arm/plat-omap/include/plat/omap-serial.h
> index b5117bd..69e6d4b 100644
> --- a/arch/arm/plat-omap/include/plat/omap-serial.h
> +++ b/arch/arm/plat-omap/include/plat/omap-serial.h
> @@ -79,6 +79,7 @@ struct omap_uart_port_info {
>  	void __iomem *wk_st;
>  	void __iomem *wk_en;
>  	u32 wk_mask;
> +	bool			has_async_wake;
>  };
>  
>  struct uart_omap_dma {
> @@ -134,6 +135,8 @@ struct uart_omap_port {
>  	unsigned int		errata;
>  	void (*enable_wakeup)(struct platform_device *, bool);
>  	bool (*chk_wakeup)(struct platform_device *);
> +
> +	bool			has_async_wake;
>  };
>  
>  #endif /* __OMAP_SERIAL_H__ */
> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
> index c3561dd..dbe76f3 100644
> --- a/drivers/tty/serial/omap-serial.c
> +++ b/drivers/tty/serial/omap-serial.c
> @@ -1181,6 +1181,13 @@ static int serial_omap_suspend(struct device *dev)
>  		uart_suspend_port(&serial_omap_reg, &up->port);
>  		console_trylock();
>  		serial_omap_pm(&up->port, 3, 0);
> +
> +		/* OMAP2 dont have async wakeup from prcm.
> +		 * For such socs clocks will be kept active from probe and
> +		 * cut only in suspend path.
> +		 */
> +		if (!up->has_async_wake)
> +			serial_omap_port_disable(up);
>  	}
>  	return 0;
>  }
> @@ -1192,6 +1199,9 @@ static int serial_omap_resume(struct device *dev)
>  	if (up) {
>  		uart_resume_port(&serial_omap_reg, &up->port);
>  		console_unlock();
> +
> +		if (!up->has_async_wake)
> +			serial_omap_port_enable(up);
>  	}
>  
>  	return 0;
> @@ -1415,6 +1425,7 @@ static int serial_omap_probe(struct platform_device *pdev)
>  	up->errata = omap_up_info->errata;
>  	up->enable_wakeup = omap_up_info->enable_wakeup;
>  	up->chk_wakeup = omap_up_info->chk_wakeup;
> +	up->has_async_wake = omap_up_info->has_async_wake;
>  
>  	if (omap_up_info->dma_enabled) {
>  		up->uart_dma.uart_dma_tx = dma_tx->start;
> @@ -1443,6 +1454,9 @@ static int serial_omap_probe(struct platform_device *pdev)
>  		serial_omap_port_disable(up);
>  	}
>  
> +	if (!up->has_async_wake)
> +		serial_omap_port_enable(up);
> +
>  	ui[pdev->id] = up;
>  	serial_omap_add_console_port(up);