RE: [PATCH 4/5 V2] usb: call pm_runtime_put_sync inpm_runtime_get_sync failed case

From: Liu, Chuansheng
Date: Thu Feb 28 2013 - 21:08:18 EST




> -----Original Message-----
> From: Li, Fei
> Sent: Thursday, February 28, 2013 5:06 PM
> To: gregkh@xxxxxxxxxxxxxxxxxxx; Lan, Tianyu; stern@xxxxxxxxxxxxxxxxxxx;
> sarah.a.sharp@xxxxxxxxxxxxxxx
> Cc: rjw@xxxxxxx; linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Liu,
> Chuansheng; Li, Fei
> Subject: [PATCH 4/5 V2] usb: call pm_runtime_put_sync in
> pm_runtime_get_sync failed case
>
>
> Even in failed case of pm_runtime_get_sync, the usage_count
> is incremented. In order to keep the usage_count with correct
> value and runtime power management to behave correctly, call
> pm_runtime_put(_sync) in such case.
>
> Signed-off-by Liu Chuansheng <chuansheng.liu@xxxxxxxxx>
> Signed-off-by: Li Fei <fei.li@xxxxxxxxx>
> ---
> drivers/usb/core/hub.c | 3 ++-
> 1 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 5480352..f72dede 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -3148,12 +3148,13 @@ int usb_port_resume(struct usb_device *udev,
> pm_message_t msg)
>
> if (port_dev->did_runtime_put) {
> status = pm_runtime_get_sync(&port_dev->dev);
> - port_dev->did_runtime_put = false;
> if (status < 0) {
> dev_dbg(&udev->dev, "can't resume usb port, status %d\n",
> status);
> + pm_runtime_put_sync(&port_dev->dev);
Rechecked the usb similar codes, in usb_autoresume_device() and usb_autopm_get_interface(),
when pm_runtime_get_sync() failed, the paired pm_runtime_put_sync() will be called.
Alan and Rafael, is it reasonable to consider this cleanup patch also? Thanks.

> return status;
> }
> + port_dev->did_runtime_put = false;
> }
>
> /* Skip the initial Clear-Suspend step for a remote wakeup */
> --
> 1.7.4.1
>
>

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