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From: Bin Liu <b-liu@ti.com>
To: Dinghao Liu <dinghao.liu@zju.edu.cn>
Cc: <kjlu@umn.edu>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	<linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] usb: musb: Fix runtime PM imbalance on error
Date: Thu, 21 May 2020 15:37:28 -0500	[thread overview]
Message-ID: <20200521203728.GB25575@iaqt7> (raw)
In-Reply-To: <20200521073547.18828-1-dinghao.liu@zju.edu.cn>

Hi,

On Thu, May 21, 2020 at 03:35:47PM +0800, Dinghao Liu wrote:
> When copy_from_user() returns an error code, a pairing
> runtime PM usage counter decrement is needed to keep
> the counter balanced.
> 
> Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
> ---
>  drivers/usb/musb/musb_debugfs.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c
> index 7b6281ab62ed..837c38a5e4ef 100644
> --- a/drivers/usb/musb/musb_debugfs.c
> +++ b/drivers/usb/musb/musb_debugfs.c
> @@ -178,8 +178,11 @@ static ssize_t musb_test_mode_write(struct file *file,
>  
>  	memset(buf, 0x00, sizeof(buf));
>  
> -	if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
> +	if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) {
> +		pm_runtime_mark_last_busy(musb->controller);
> +		pm_runtime_put_autosuspend(musb->controller);
>  		return -EFAULT;
> +	}

Thanks for catching the bug. Can you please instead move these lines to
the beginning of this function so that pm_runtime_get_sync() is not
called if copy_from_user() failed?

-Bin.

  reply	other threads:[~2020-05-21 20:37 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-21  7:35 [PATCH] usb: musb: Fix runtime PM imbalance on error Dinghao Liu
2020-05-21 20:37 ` Bin Liu [this message]
2020-05-22  1:23   ` dinghao.liu

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