Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754518Ab2ELT2Y (ORCPT ); Sat, 12 May 2012 15:28:24 -0400 Received: from eu1sys200aog110.obsmtp.com ([207.126.144.129]:59523 "EHLO eu1sys200aog110.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753702Ab2ELT2W convert rfc822-to-8bit (ORCPT ); Sat, 12 May 2012 15:28:22 -0400 From: Bhupesh SHARMA To: "laurent.pinchart@ideasonboard.com" , "linux-usb@vger.kernel.org" Cc: "balbi@ti.com" , "linux-kernel@vger.kernel.org" Date: Sun, 13 May 2012 03:27:55 +0800 Subject: RE: [PATCH 1/1] usb: gadget/uvc: Add support for 'USB_GADGET_DELAYED_STATUS' response for a set_intf(alt-set 1) command Thread-Topic: [PATCH 1/1] usb: gadget/uvc: Add support for 'USB_GADGET_DELAYED_STATUS' response for a set_intf(alt-set 1) command Thread-Index: Ac0sIMmP5xhaoWIvTginCXmsHL18rQEVCdpA Message-ID: References: <65fb24c9f639ec8cedab04799bc59d43c5683a08.1336374550.git.bhupesh.sharma@st.com> In-Reply-To: <65fb24c9f639ec8cedab04799bc59d43c5683a08.1336374550.git.bhupesh.sharma@st.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5397 Lines: 166 Hi Laurent, I know you are very busy these days with the dmabuf, vb2 and v4l2 stuff :) But, can you please have a look at this patch and let me know if this is ok or do I need to do some modifications in the same. Regards, Bhupesh > -----Original Message----- > From: Bhupesh SHARMA > Sent: Monday, May 07, 2012 12:43 PM > To: laurent.pinchart@ideasonboard.com; linux-usb@vger.kernel.org > Cc: balbi@ti.com; linux-kernel@vger.kernel.org; Bhupesh SHARMA > Subject: [PATCH 1/1] usb: gadget/uvc: Add support for > 'USB_GADGET_DELAYED_STATUS' response for a set_intf(alt-set 1) command > > This patch adds the support in UVC webcam gadget design for providing > USB_GADGET_DELAYED_STATUS in response to a set_interface(alt setting 1) > command > issue by the Host. > > The current UVC webcam gadget design generates a STREAMON event > corresponding > to a set_interface(alt setting 1) command from the Host. > This STREAMON event will eventually be routed to a real V4L2 device. > > To start video streaming, it may be required to perform some register > writes to > a camera sensor device over slow external busses like I2C or SPI. So, > it makes > sense to ensure that we delay the STATUS stage of the > set_interface(alt setting 1) command. > > Otherwise, a lot of ISOC IN tokens sent by the Host will be replied to > by > zero-length packets by the webcam device. On certain Hosts this may > even lead to > ISOC URBs been cancelled from the Host side. > > So, as soon as we finish doing all the "streaming" related stuff on the > real > V4L2 device, we call a STREAMON ioctl on the UVC side and from here we > call > the 'usb_composite_setup_continue' function to complete the status > stage of > the set_interface(alt setting 1) command. > > Signed-off-by: Bhupesh Sharma > --- > drivers/usb/gadget/f_uvc.c | 12 +++++++++++- > drivers/usb/gadget/uvc.h | 4 ++++ > drivers/usb/gadget/uvc_v4l2.c | 27 +++++++++++++++++++++++++-- > 3 files changed, 40 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/gadget/f_uvc.c b/drivers/usb/gadget/f_uvc.c > index d2569b2..6f084e3 100644 > --- a/drivers/usb/gadget/f_uvc.c > +++ b/drivers/usb/gadget/f_uvc.c > @@ -209,6 +209,14 @@ uvc_function_get_alt(struct usb_function *f, > unsigned interface) > return uvc->state == UVC_STATE_STREAMING ? 1 : 0; > } > > +void > +uvc_process_setup_continue(struct uvc_device *uvc) > +{ > + struct usb_composite_dev *cdev = uvc->func.config->cdev; > + > + usb_composite_setup_continue(cdev); > +} > + > static int > uvc_function_set_alt(struct usb_function *f, unsigned interface, > unsigned alt) > { > @@ -271,7 +279,9 @@ uvc_function_set_alt(struct usb_function *f, > unsigned interface, unsigned alt) > v4l2_event_queue(uvc->vdev, &v4l2_event); > > uvc->state = UVC_STATE_STREAMING; > - break; > + uvc->vdev_is_streaming = false; > + > + return USB_GADGET_DELAYED_STATUS; > > default: > return -EINVAL; > diff --git a/drivers/usb/gadget/uvc.h b/drivers/usb/gadget/uvc.h > index bc78c60..56ac883 100644 > --- a/drivers/usb/gadget/uvc.h > +++ b/drivers/usb/gadget/uvc.h > @@ -168,6 +168,9 @@ struct uvc_device > /* Events */ > unsigned int event_length; > unsigned int event_setup_out : 1; > + > + /* flags */ > + bool vdev_is_streaming; > }; > > static inline struct uvc_device *to_uvc(struct usb_function *f) > @@ -188,6 +191,7 @@ struct uvc_file_handle > * Functions > */ > > +extern void uvc_process_setup_continue(struct uvc_device *uvc); > extern void uvc_endpoint_stream(struct uvc_device *dev); > > extern void uvc_function_connect(struct uvc_device *uvc); > diff --git a/drivers/usb/gadget/uvc_v4l2.c > b/drivers/usb/gadget/uvc_v4l2.c > index f761bcb..379d8ac 100644 > --- a/drivers/usb/gadget/uvc_v4l2.c > +++ b/drivers/usb/gadget/uvc_v4l2.c > @@ -242,7 +242,18 @@ uvc_v4l2_do_ioctl(struct file *file, unsigned int > cmd, void *arg) > if ((ret = uvc_queue_buffer(&video->queue, arg)) < 0) > return ret; > > - return uvc_video_pump(video); > + /* > + * for the very first QBUF calls (until STREAMON is > + * called) we just need to queue the buffers and start > + * pumping the data to USB side only after STREAMON has > + * been called which is handled by the STREAMON case > + * below. For QBUF calls after STREAMON, we need to pump > + * the data to the USB side here itself. > + */ > + if (uvc->vdev_is_streaming) > + return uvc_video_pump(video); > + > + return 0; > > case VIDIOC_DQBUF: > return uvc_dequeue_buffer(&video->queue, arg, > @@ -255,7 +266,19 @@ uvc_v4l2_do_ioctl(struct file *file, unsigned int > cmd, void *arg) > if (*type != video->queue.type) > return -EINVAL; > > - return uvc_video_enable(video, 1); > + ret = uvc_video_enable(video, 1); > + if (ret < 0) > + return ret; > + > + /* > + * since the real video device has now started streaming > + * its safe now to complete the status phase of the > + * set_interface (alt setting 1) > + */ > + uvc_process_setup_continue(uvc); > + uvc->vdev_is_streaming = true; > + > + return 0; > } > > case VIDIOC_STREAMOFF: > -- > 1.7.2.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/