"Govindraj.R" <govindraj.raja@xxxxxx> writes:
> For omap2 cpu_idle thread will not be available
Why not?
> and uart_clock cutting happens only in suspend path.
Aren't clocks also cut after runtime PM autosuspend?
> Prior to this patch the uart_clock was cut using prepare/resume
> calls since these funcs are no more available with runtime
> changes use no_async_wake flag to keep clock active during bootup
> otherwise uart port will disabled during boot-up and cannot be
> enabled back.
This doesn't just keep clock active during bootup, but it keeps clock
active always, except during suspend.
> Also based on this flag we can disable uart port during suspend
> and enable back during resume.
I think disabling UART port during suspend should already be part of an
earlier patch. This patch should then only make it conditional.
> Signed-off-by: Govindraj.R <govindraj.raja@xxxxxx>
> ---
> arch/arm/mach-omap2/serial.c | 7 +++++++
> arch/arm/plat-omap/include/plat/omap-serial.h | 3 +++
> drivers/tty/serial/omap-serial.c | 14 ++++++++++++++
> 3 files changed, 24 insertions(+), 0 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
> index d4ef370..1af9fd5 100644
> --- a/arch/arm/mach-omap2/serial.c
> +++ b/arch/arm/mach-omap2/serial.c
> @@ -245,6 +245,12 @@ static void omap_uart_wakeup_enable(struct platform_device *pdev, bool enable)
> static void omap_uart_idle_init(struct omap_uart_port_info *uart,
> unsigned short num)
> {
> + /* On omap2 no cpu_idle and async wakeup from prcm_module.
Please remove comments about CPU idle, as the need for this has nothing
to do with CPU idle.
> + * This flag can be used to cut clocks only in suspend path.
> + * to avoid boot break due to aggressive clock cutting from
> + * omap-serial driver.
> + */
fix multi-line comment style throughout
> + uart->no_async_wake = true;
If needed (which I still don't think I understand), for readability sake
this flag should be called 'has_async_wake', and default to false. It
should then be set to true on available SoCs.
Kevin
> if (cpu_is_omap34xx()) {
> u32 mod = num > 1 ? OMAP3430_PER_MOD : CORE_MOD;
> u32 wk_mask = 0;
> @@ -266,6 +272,7 @@ static void omap_uart_idle_init(struct omap_uart_port_info *uart,
> break;
> }
> uart->wk_mask = wk_mask;
> + uart->no_async_wake = false;
> } 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..1de5bc4 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 no_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 no_async_wake;
> };
>
> #endif /* __OMAP_SERIAL_H__ */
> diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
> index eea478c..59f548f 100644
> --- a/drivers/tty/serial/omap-serial.c
> +++ b/drivers/tty/serial/omap-serial.c
> @@ -1168,6 +1168,13 @@ 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 cpu_idle thread and async wakeup from prcm.
> + * For such socs clocks will be kept active from probe and
> + * cut only in suspend path.
> + */
> + if (up->no_async_wake)
> + serial_omap_port_disable(up);
> }
> return 0;
> }
> @@ -1179,6 +1186,9 @@ static int serial_omap_resume(struct device *dev)
> if (up) {
> uart_resume_port(&serial_omap_reg, &up->port);
> console_unlock();
> +
> + if (up->no_async_wake)
> + serial_omap_port_enable(up);
> }
>
> return 0;
> @@ -1402,6 +1412,7 @@ 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->no_async_wake = omap_up_info->no_async_wake;
>
> if (omap_up_info->dma_enabled) {
> up->uart_dma.uart_dma_tx = dma_tx->start;
> @@ -1430,6 +1441,9 @@ static int serial_omap_probe(struct platform_device *pdev)
> serial_omap_port_disable(up);
> }
>
> + if (up->no_async_wake)
> + serial_omap_port_enable(up);
> +
> ui[pdev->id] = up;
> serial_omap_add_console_port(up);
--
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