On Tue, Mar 25, 2014 at 11:48:47AM -0700, Tony Lindgren wrote:
> The lack of pm_runtime_resume handling for the device state leads into
> device wake-up interrupts not working after a while for runtime PM.
>
> Also, serial-omap is confused about the use of device_may_wakeup.
> The checks for device_may_wakeup should only be done for suspend and
> resume, not for pm_runtime_suspend and pm_runtime_resume. The wake-up
> events for PM runtime should always be enabled.
>
> The lack of pm_runtime_resume handling leads into device wake-up
> interrupts not working after a while for runtime PM.
>
> Rather than try to patch over the issue of adding complex tests to
> the pm_runtime_resume, let's fix the issues properly:
>
> 1. Make serial_omap_enable_wakeup deal with all internal PM state
> handling so we don't need to test for up->wakeups_enabled elsewhere.
>
> Later on once omap3 boots in device tree only mode we can also
> remove the up->wakeups_enabled flag and rely on the wake-up
> interrupt enable/disable state alone.
>
> 2. Do the device_may_wakeup checks in suspend and resume only,
> for runtime PM the wake-up events need to be always enabled.
>
> 3. Finally just call serial_omap_enable_wakeup and make sure we
> call it also in pm_runtime_resume.
>
> 4. Note that we also have to use disable_irq_nosync as serial_omap_irq
> calls pm_runtime_get_sync.
>
> Fixes: 2a0b965cfb6e (serial: omap: Add support for optional wake-up)
> Cc: stable@xxxxxxxxxxxxxxx # v3.13+
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
>
> --- a/drivers/tty/serial/omap-serial.c
> +++ b/drivers/tty/serial/omap-serial.c
> @@ -225,14 +225,19 @@ static inline void serial_omap_enable_wakeirq(struct uart_omap_port *up,
> if (enable)
> enable_irq(up->wakeirq);
> else
> - disable_irq(up->wakeirq);
> + disable_irq_nosync(up->wakeirq);
looks to me liket his should be a separate fix of its own...
> static void serial_omap_enable_wakeup(struct uart_omap_port *up, bool enable)
> {
> struct omap_uart_port_info *pdata = dev_get_platdata(up->dev);
>
> + if (enable == up->wakeups_enabled)
> + return;
is there any case where you would call this function twice with the same
argument ?
> +
> serial_omap_enable_wakeirq(up, enable);
> + up->wakeups_enabled = enable;
> +
> if (!pdata || !pdata->enable_wakeup)
> return;
>
> @@ -1495,6 +1500,11 @@ static int serial_omap_suspend(struct device *dev)
> uart_suspend_port(&serial_omap_reg, &up->port);
> flush_work(&up->qos_work);
>
> + if (device_may_wakeup(dev))
> + serial_omap_enable_wakeup(up, true);
> + else
> + serial_omap_enable_wakeup(up, false);
> +
> return 0;
> }
>
> @@ -1502,6 +1512,9 @@ static int serial_omap_resume(struct device *dev)
> {
> struct uart_omap_port *up = dev_get_drvdata(dev);
>
> + if (device_may_wakeup(dev))
> + serial_omap_enable_wakeup(up, false);
> +
> uart_resume_port(&serial_omap_reg, &up->port);
>
> return 0;
> @@ -1877,17 +1890,7 @@ static int serial_omap_runtime_suspend(struct device *dev)
>
> up->context_loss_cnt = serial_omap_get_context_loss_count(up);
>
> - if (device_may_wakeup(dev)) {
> - if (!up->wakeups_enabled) {
> - serial_omap_enable_wakeup(up, true);
> - up->wakeups_enabled = true;
> - }
> - } else {
> - if (up->wakeups_enabled) {
> - serial_omap_enable_wakeup(up, false);
> - up->wakeups_enabled = false;
> - }
> - }
> + serial_omap_enable_wakeup(up, true);
>
> up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
> schedule_work(&up->qos_work);
> @@ -1901,6 +1904,8 @@ static int serial_omap_runtime_resume(struct device *dev)
>
> int loss_cnt = serial_omap_get_context_loss_count(up);
>
> + serial_omap_enable_wakeup(up, false);
> +
> if (loss_cnt < 0) {
> dev_dbg(dev, "serial_omap_get_context_loss_count failed : %d\n",
> loss_cnt);
--
balbi
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