Re: Philips Monitor with webcam

[Mauro Carvalho Chehab <mchehab+huawei@kernel.org>]

Em Wed, 04 Nov 2020 20:43:27 +0100
Gregor Hlawacek <g.hlawacek@hzdr.de> escreveu:

I'm c/c Laurent, as he is the author of the UVC driver.

> On Wed, 2020-11-04 at 17:45 +0100, Mauro Carvalho Chehab wrote:
> > Em Wed, 04 Nov 2020 17:25:48 +0100
> > Gregor Hlawacek <g.hlawacek@hzdr.de> escreveu:
> >   
> > > On Wed, 2020-11-04 at 17:02 +0100, Mauro Carvalho Chehab wrote:  
> > > > Em Wed, 04 Nov 2020 14:24:34 +0100
> > > > Gregor Hlawacek <g.hlawacek@hzdr.de> escreveu:
> > > >     
> > > > > Hi all
> > > > > 
> > > > > I own a Philips Brilliance 241B which has a webcam attached.
> > > > > The
> > > > > device
> > > > > is listed as 0412:612b Chicony Electronics Co., Ltd, bubt
> > > > > doesn't
> > > > > work
> > > > > with the latest UVC stock kernel driver. Is there any hope to
> > > > > get
> > > > > this
> > > > > supported?
> > > > > 
> > > > > uname -a:
> > > > > Linux it72 5.9.3-arch1-1 #1 SMP PREEMPT Sun, 01 Nov 2020
> > > > > 12:58:59
> > > > > +0000
> > > > > x86_64 GNU/Linux
> > > > > 
> > > > > running Arch Linux on a Lenovo Thinkpad  T490s
> > > > > 
> > > > > dmesg:
> > > > > 
> > > > > [76850.137838] usb 3-1.1.1.2: New USB device found,
> > > > > idVendor=04f2,
> > > > > idProduct=b612, bcdDevice= 2.10
> > > > > [76850.137841] usb 3-1.1.1.2: New USB device strings: Mfr=1,
> > > > > Product=2,
> > > > > SerialNumber=3
> > > > > [76850.137843] usb 3-1.1.1.2: Product: USB2.0 FHD UVC WebCam
> > > > > [76850.137845] usb 3-1.1.1.2: Manufacturer: SunplusIT Inc
> > > > > [76850.137846] usb 3-1.1.1.2: SerialNumber: 01.00.00
> > > > > [76850.152761] uvcvideo: Found UVC 1.50 device USB2.0 FHD UVC
> > > > > WebCam
> > > > > (04f2:b612)
> > > > > [76850.215683] input: USB2.0 FHD UVC WebCam: USB2.0 F as
> > > > > /devices/pci0000:00/0000:00:1c.4/0000:04:00.0/0000:05:02.0/0000
> > > > > :3c:
> > > > > 00.0
> > > > > /usb3/3-1/3-1.1/3-1.1.1/3-1.1.1.2/3-1.1.1.2:1.0/input/input66
> > > > > [76850.223642] uvcvideo: Found UVC 1.50 device USB2.0 FHD UVC
> > > > > WebCam
> > > > > (04f2:b612)
> > > > > [76850.232499] usb 4-1.1.2: new SuperSpeed Gen 1 USB device
> > > > > number
> > > > > 5
> > > > > using xhci_hcd
> > > > > [76850.241004] input: USB2.0 FHD UVC WebCam: IR Camer as
> > > > > /devices/pci0000:00/0000:00:1c.4/0000:04:00.0/0000:05:02.0/0000
> > > > > :3c:
> > > > > 00.0
> > > > > /usb3/3-1/3-1.1/3-1.1.1/3-1.1.1.2/3-1.1.1.2:1.2/input/input67    
> > > > 
> > > > Hmm... it sounds that the camera was properly detected here. 
> > > > 
> > > > Could you please enclose the contents of the following command?
> > > > 
> > > >         $ v4l2-ctl --all
> > > > 
> > > > Thanks,
> > > > Mauro    
> > > 
> > > Hi Mauro 
> > > 
> > > thanks for the quick answer. Here is the output but I am pretty
> > > sure
> > > that this come from the integrated laptop camera and not the one in
> > > the
> > > external monitor  
> > 
> > Well, you can use "-d" parameter to identify the device, like:
> > 
> >         $ v4l2-ctl -d /dev/v4l/by-path/pci-0000\:00\:14.0-usb-
> > 0\:3.2\:1.0-video-index0 --all
> > 
> > The real path depends on your camera - you can take a look at:
> > 
> >         $ tree /dev/v4l/
> >         /dev/v4l/
> >         ├── by-id
> >         │   ├── usb-046d_HD_Pro_Webcam_C920_55DA1CCF-video-index0 ->
> > ../../video0
> >         │   └── usb-046d_HD_Pro_Webcam_C920_55DA1CCF-video-index1 ->
> > ../../video1
> >         └── by-path
> >             ├── pci-0000:00:14.0-usb-0:3.2:1.0-video-index0 ->
> > ../../video0
> >             └── pci-0000:00:14.0-usb-0:3.2:1.0-video-index1 ->
> > ../../video1
> > 
> >         
> > In order to check the ones that were detected.
> > 
> > Regards,
> > Mauro  
> ├── by-id
> │   ├── usb-Chicony_Electronics_Co._Ltd._Integrated_Camera_0001-video-
> index0 -> ../../video0
> │   ├── usb-Chicony_Electronics_Co._Ltd._Integrated_Camera_0001-video-
> index1 -> ../../video1

Ok. So, /dev/video0 is the video streaming device (and /dev/video1
carries on metadata).


> │   ├── usb-SunplusIT_Inc_USB2.0_FHD_UVC_WebCam_01.00.00-video-index0 -
> > ../../video4  
> │   └── usb-SunplusIT_Inc_USB2.0_FHD_UVC_WebCam_01.00.00-video-index1 -
> > ../../video5  
> └── by-path
>     ├── pci-0000:00:14.0-usb-0:8:1.0-video-index0 -> ../../video0
>     ├── pci-0000:00:14.0-usb-0:8:1.0-video-index1 -> ../../video1
>     ├── pci-0000:3c:00.0-usb-0:1.1.1.2:1.0-video-index0 -> ../../video2
>     ├── pci-0000:3c:00.0-usb-0:1.1.1.2:1.0-video-index1 -> ../../video3
>     ├── pci-0000:3c:00.0-usb-0:1.1.1.2:1.2-video-index0 -> ../../video4
>     └── pci-0000:3c:00.0-usb-0:1.1.1.2:1.2-video-index1 -> ../../video5
> 
> It seems non of them responds. They are either busy, can not be opened
> or fail to produce any response.
> 
> sudo v4l2-ctl -d /dev/v4l/by-id/usb-
> sunplusIT_Inc_USB2.0_FHD_UVC_WebCam_01.00.00-video-index0
> Failed to open /dev/v4l/by-id/usb-
> SunplusIT_Inc_USB2.0_FHD_UVC_WebCam_01.00.00-video-index0: Device or
> resource busy

Weird. It is not usual to receive -EBUSY if there's no other program
using the device at the same time.

Yet, from what I understood, on this device, the camera is hidden inside
the monitor until an application tries to use it.

While uvc driver has support for Linux PM, perhaps this specific
device requires some extra command to turn the camera on and to 
open it from the monitor case.

After you called v4l2-ctl, does any message appears at dmesg?

Thanks,
Mauro