Hi, some more trivial comments below.
On Fri, Oct 06, 2017 at 05:51:34PM +0200, srinivas.kandagatla@xxxxxxxxxx wrote:
> From: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
>
> Slimbus HW mandates that clock-pause sequence has to be executed
> before disabling relevant interface and core clocks.
> Runtime-PM's autosuspend feature is used here to enter/exit low
> power mode for Qualcomm's Slimbus controller. Autosuspend feature
> enables driver to avoid changing power-modes too frequently since
> entering clock-pause is an expensive sequence
>
> Signed-off-by: Sagar Dharia <sdharia@xxxxxxxxxxxxxx>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
[...]
> +static int msm_clk_pause_wakeup(struct slim_controller *ctrl)
> +{
> + struct msm_slim_ctrl *dev = slim_get_ctrldata(ctrl);
> +
> + clk_prepare_enable(dev->hclk);
> + clk_prepare_enable(dev->rclk);
> + enable_irq(dev->irq);
> +
> + writel_relaxed(1, dev->base + FRM_WAKEUP);
> + /* Make sure framer wakeup write goes through before ISR fires */
> + mb();
> + /**
This isn't really a kerneldoc comment.
> + * HW Workaround: Currently, slave is reporting lost-sync messages
> + * after slimbus comes out of clock pause.
> + * Transaction with slave fail before slave reports that message
> + * Give some time for that report to come
> + * Slimbus wakes up in clock gear 10 at 24.576MHz. With each superframe
> + * being 250 usecs, we wait for 5-10 superframes here to ensure
> + * we get the message
> + */
> + usleep_range(1250, 2500);
> + return 0;
> +}
[...]
> +#ifdef CONFIG_PM_SLEEP
> +static int msm_slim_suspend(struct device *dev)
> +{
> + int ret = 0;
> +
> + if (!pm_runtime_enabled(dev) ||
> + (!pm_runtime_suspended(dev))) {
> + dev_dbg(dev, "system suspend");
> + ret = msm_slim_runtime_suspend(dev);
> + }
> + if (ret == -EISCONN) {
> + /**
ditto.
Also, it looks misindented.
> + * If the clock pause failed due to active channels, there is
> + * a possibility that some audio stream is active during suspend.
> + * (e.g. modem usecase during suspend)
> + * We dont want to return suspend failure in that case so that
> + * display and relevant components can still go to suspend.
> + * If there is some other error, then it should prevent
> + * system level suspend
> + */
> + ret = 0;
> + }
> + return ret;
> +}
Thanks,
Jonathan Neuschäfer
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