netdev - RE: [PATCH 3/3] usb: renesas_usbhs: Remove dummy runtime PM callbacks

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Date:   Thu, 25 Oct 2018 02:45:18 +0000
From:   Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>
To:     Jarkko Nikula <jarkko.nikula@...ux.intel.com>,
        "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>
CC:     "linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
        Wolfram Sang <wsa+renesas@...g-engineering.com>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        "David S . Miller" <davem@...emloft.net>,
        Sergei Shtylyov <sergei.shtylyov@...entembedded.com>,
        "linux-renesas-soc@...r.kernel.org" 
        <linux-renesas-soc@...r.kernel.org>,
        "linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>
Subject: RE: [PATCH 3/3] usb: renesas_usbhs: Remove dummy runtime PM callbacks

Hi Jarkko,

> From: Jarkko Nikula, Sent: Wednesday, October 24, 2018 10:52 PM
> 
> Platform drivers don't need dummy runtime PM callbacks that just return
> success in order to have runtime PM happening. This has changed since
> following commits:
> 
> 05aa55dddb9e ("PM / Runtime: Lenient generic runtime pm callbacks")
> 543f2503a956 ("PM / platform_bus: Allow runtime PM by default")
> 8b313a38ecff ("PM / Platform: Use generic runtime PM callbacks directly")
> 
> Signed-off-by: Jarkko Nikula <jarkko.nikula@...ux.intel.com>
> ---
> Only build tested.

Thank you for the patch!

Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>

> ---
>  drivers/usb/renesas_usbhs/common.c | 14 --------------
>  1 file changed, 14 deletions(-)
> 
> diff --git a/drivers/usb/renesas_usbhs/common.c b/drivers/usb/renesas_usbhs/common.c
> index a3e1290d682d..0e760f228dd8 100644
> --- a/drivers/usb/renesas_usbhs/common.c
> +++ b/drivers/usb/renesas_usbhs/common.c
> @@ -874,23 +874,9 @@ static int usbhsc_resume(struct device *dev)
>  	return 0;
>  }
> 
> -static int usbhsc_runtime_nop(struct device *dev)
> -{
> -	/* Runtime PM callback shared between ->runtime_suspend()
> -	 * and ->runtime_resume(). Simply returns success.
> -	 *
> -	 * This driver re-initializes all registers after
> -	 * pm_runtime_get_sync() anyway so there is no need
> -	 * to save and restore registers here.
> -	 */

I guess this code came from i2c-sh_mobile.c or sh_eth.c
and we didn't realize this code didn't need at that time (Oct 10 2011).

Best regards,
Yoshihiro Shimoda

> -	return 0;
> -}
> -
>  static const struct dev_pm_ops usbhsc_pm_ops = {
>  	.suspend		= usbhsc_suspend,
>  	.resume			= usbhsc_resume,
> -	.runtime_suspend	= usbhsc_runtime_nop,
> -	.runtime_resume		= usbhsc_runtime_nop,
>  };
> 
>  static struct platform_driver renesas_usbhs_driver = {
> --
> 2.19.1