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SubjectRe: [Patch v6 5/7] slimbus: qcom: Add runtime-pm support using clock-pause feature
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Thanks for the review comments

On 07/10/17 09:22, Jonathan Neuschäfer wrote:
> Hi, some more trivial comments below.
>
> On Fri, Oct 06, 2017 at 05:51:34PM +0200, srinivas.kandagatla@linaro.org wrote:
>> From: Sagar Dharia <sdharia@codeaurora.org>
>>
>> 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@codeaurora.org>
>> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
>> ---
> [...]
>> +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.
Yep I agree will fix all such instances.

>
>> + * 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.
Yep. will fix this too.

>
>> + * 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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