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From: Felipe Balbi <balbi@ti.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Simon Haggett <simon.haggett@realvnc.com>,
	Li Yang-R58472 <r58472@freescale.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	balbi@ti.com,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH 1/1] usb: gadget: Don't attempt to dequeue requests for a disabled USB endpoint on Freescale hardware
Date: Fri, 26 Oct 2012 11:14:48 +0300	[thread overview]
Message-ID: <20121026081448.GD23501@arwen.pp.htv.fi> (raw)
In-Reply-To: <3862785.b8vaFMSbLQ@avalon>

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Hi,

On Thu, Oct 25, 2012 at 02:36:24AM +0200, Laurent Pinchart wrote:
> Hi Felipe,
> 
> On Monday 22 October 2012 13:56:01 Felipe Balbi wrote:
> > On Mon, Oct 22, 2012 at 12:47:21PM +0200, Laurent Pinchart wrote:
> > > On Monday 22 October 2012 03:33:19 Li Yang-R58472 wrote:
> > > > On Saturday, October 20, 2012 1:37 AM Felipe Balbi wrote:
> > > > > On Fri, Oct 19, 2012 at 06:19:26PM +0100, Simon Haggett wrote:
> > > > > > Some gadget drivers may attempt to dequeue requests for an endpoint
> > > > > > that has already been disabled. For example, in the UVC gadget
> > > > > > driver, uvc_function_set_alt() will call usb_ep_disable() when alt
> > > > > > setting 0 is selected. When the userspace application subsequently
> > > > > > issues the VIDIOC_STREAMOFF ioctl, uvc_video_enable() invokes
> > > > > > usb_ep_dequeue() to ensure that all requests have been cancelled.
> > > > > 
> > > > > bug is on uvc gadget, then. Laurent ?
> > > 
> > > We've discussed this topic a couple of months before. I believe that's not
> > > a bug.
> > > 
> > > http://68.183.106.108/lists/linux-usb/msg68869.html
> > 
> > fair enough :-)
> > 
> > That's a different case, however. At the link above we're discussing
> > dequeueing a request which is already being dequeued. $SUBJECT is trying
> > to fix dequeueing of a request for an endpoint which isn't even enabled.
> 
> You've got a point there :-) That's a different case indeed, I'm open to (at 
> least evaluating) a fix in the UVC gadget driver if you think that's better.

I _do_ think that's better. If the endpoint isn't even enabled, why are
you trying to dequeue a request ? :-)

cheers

-- 
balbi

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WARNING: multiple messages have this Message-ID (diff)
From: Felipe Balbi <balbi@ti.com>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: <balbi@ti.com>, Li Yang-R58472 <r58472@freescale.com>,
	Simon Haggett <simon.haggett@realvnc.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/1] usb: gadget: Don't attempt to dequeue requests for a disabled USB endpoint on Freescale hardware
Date: Fri, 26 Oct 2012 11:14:48 +0300	[thread overview]
Message-ID: <20121026081448.GD23501@arwen.pp.htv.fi> (raw)
In-Reply-To: <3862785.b8vaFMSbLQ@avalon>

[-- Attachment #1: Type: text/plain, Size: 1695 bytes --]

Hi,

On Thu, Oct 25, 2012 at 02:36:24AM +0200, Laurent Pinchart wrote:
> Hi Felipe,
> 
> On Monday 22 October 2012 13:56:01 Felipe Balbi wrote:
> > On Mon, Oct 22, 2012 at 12:47:21PM +0200, Laurent Pinchart wrote:
> > > On Monday 22 October 2012 03:33:19 Li Yang-R58472 wrote:
> > > > On Saturday, October 20, 2012 1:37 AM Felipe Balbi wrote:
> > > > > On Fri, Oct 19, 2012 at 06:19:26PM +0100, Simon Haggett wrote:
> > > > > > Some gadget drivers may attempt to dequeue requests for an endpoint
> > > > > > that has already been disabled. For example, in the UVC gadget
> > > > > > driver, uvc_function_set_alt() will call usb_ep_disable() when alt
> > > > > > setting 0 is selected. When the userspace application subsequently
> > > > > > issues the VIDIOC_STREAMOFF ioctl, uvc_video_enable() invokes
> > > > > > usb_ep_dequeue() to ensure that all requests have been cancelled.
> > > > > 
> > > > > bug is on uvc gadget, then. Laurent ?
> > > 
> > > We've discussed this topic a couple of months before. I believe that's not
> > > a bug.
> > > 
> > > http://68.183.106.108/lists/linux-usb/msg68869.html
> > 
> > fair enough :-)
> > 
> > That's a different case, however. At the link above we're discussing
> > dequeueing a request which is already being dequeued. $SUBJECT is trying
> > to fix dequeueing of a request for an endpoint which isn't even enabled.
> 
> You've got a point there :-) That's a different case indeed, I'm open to (at 
> least evaluating) a fix in the UVC gadget driver if you think that's better.

I _do_ think that's better. If the endpoint isn't even enabled, why are
you trying to dequeue a request ? :-)

cheers

-- 
balbi

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  reply	other threads:[~2012-10-26  8:20 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-19 17:19 [PATCH 1/1] usb: gadget: Don't attempt to dequeue requests for a disabled USB endpoint on Freescale hardware Simon Haggett
2012-10-19 17:19 ` Simon Haggett
2012-10-19 17:37 ` Felipe Balbi
2012-10-19 17:37   ` Felipe Balbi
2012-10-22  3:33   ` Li Yang-R58472
2012-10-22  3:33     ` Li Yang-R58472
2012-10-22  7:53     ` Felipe Balbi
2012-10-22  7:53       ` Felipe Balbi
2012-10-22 10:47     ` Laurent Pinchart
2012-10-22 10:47       ` Laurent Pinchart
2012-10-22 10:56       ` Felipe Balbi
2012-10-22 10:56         ` Felipe Balbi
2012-10-25  0:36         ` Laurent Pinchart
2012-10-25  0:36           ` Laurent Pinchart
2012-10-26  8:14           ` Felipe Balbi [this message]
2012-10-26  8:14             ` Felipe Balbi
2012-10-22 11:49       ` Simon Haggett
2012-10-22 11:49         ` Simon Haggett
2012-10-25  0:33         ` Laurent Pinchart
2012-10-25  0:33           ` Laurent Pinchart

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