Re: [PATCH 2/5] soundwire: qcom: enable runtime pm before controller is registered

[Pierre-Louis Bossart]

On 2/9/23 07:13, Srinivas Kandagatla wrote:
> Registering controller even before pm runtime is enabled will result
> in pm runtime underflow warnings. Fix this by properly moving
> the runtime pm enable before registering controller.

That seems very odd. The Intel code configures the pm_runtime stuff
*after* the call to sdw_bus_master_add(), and we've not seen any
underflow warnings? We even configure pm_runtime after starting the bus.
Likewise for peripherals the pm_runtime part is enabled after the device
is initialized.

Not following the problem and suggested solution.

> Fixes: 74e79da9fd46 ("soundwire: qcom: add runtime pm support")
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
>  drivers/soundwire/qcom.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
> index 9d8ae77bad0a..b2363839624c 100644
> --- a/drivers/soundwire/qcom.c
> +++ b/drivers/soundwire/qcom.c
> @@ -1417,6 +1417,12 @@ static int qcom_swrm_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> +	pm_runtime_set_autosuspend_delay(dev, 3000);
> +	pm_runtime_use_autosuspend(dev);
> +	pm_runtime_mark_last_busy(dev);
> +	pm_runtime_set_active(dev);
> +	pm_runtime_enable(dev);
> +
>  	ret = sdw_bus_master_add(&ctrl->bus, dev, dev->fwnode);
>  	if (ret) {
>  		dev_err(dev, "Failed to register Soundwire controller (%d)\n",
> @@ -1435,12 +1441,6 @@ static int qcom_swrm_probe(struct platform_device *pdev)
>  		 (ctrl->version >> 24) & 0xff, (ctrl->version >> 16) & 0xff,
>  		 ctrl->version & 0xffff);
>  
> -	pm_runtime_set_autosuspend_delay(dev, 3000);
> -	pm_runtime_use_autosuspend(dev);
> -	pm_runtime_mark_last_busy(dev);
> -	pm_runtime_set_active(dev);
> -	pm_runtime_enable(dev);
> -
>  	/* Clk stop is not supported on WSA Soundwire masters */
>  	if (ctrl->version <= 0x01030000) {
>  		ctrl->clock_stop_not_supported = true;