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Date:   Fri, 8 Jul 2022 10:39:06 -0400
From:   Alan Stern <stern@rowland.harvard.edu>
To:     Jozef Martiniak <jomajm@gmail.com>
Cc:     Felipe Balbi <balbi@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jens Axboe <axboe@kernel.dk>, Hangyu Hua <hbh25y@gmail.com>,
        "Darrick J. Wong" <djwong@kernel.org>,
        Wei Ming Chen <jj251510319013@gmail.com>,
        Ingo Molnar <mingo@kernel.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] gadgetfs: ep_io - wait until IRQ finishes
Message-ID: <YshBijUt6HgPeB0U@rowland.harvard.edu>
References: <20220708070645.6130-1-jomajm@gmail.com>
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On Fri, Jul 08, 2022 at 09:06:44AM +0200, Jozef Martiniak wrote:
> after usb_ep_queue() if wait_for_completion_interruptible() is
> interrupted we need to wait until IRQ gets finished.

This should say "request" or "I/O request", not "IRQ".  Not a big deal.

> 
> Otherwise complete() from epio_complete() can corrupt stack.
> 
> Signed-off-by: Jozef Martiniak <jomajm@gmail.com>
> ---

Acked-by: Alan Stern <stern@rowland.harvard.edu>

>  drivers/usb/gadget/legacy/inode.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
> index 79990597c39f..01c3ead7d1b4 100644
> --- a/drivers/usb/gadget/legacy/inode.c
> +++ b/drivers/usb/gadget/legacy/inode.c
> @@ -362,6 +362,7 @@ ep_io (struct ep_data *epdata, void *buf, unsigned len)
>  				spin_unlock_irq (&epdata->dev->lock);
>  
>  				DBG (epdata->dev, "endpoint gone\n");
> +				wait_for_completion(&done);
>  				epdata->status = -ENODEV;
>  			}
>  		}
> -- 
> 2.25.1
>