Re: 1d6b:0001 [MSI A55M-P33] No webcam functionality with Zoran Microelectronics, Ltd Digital Camera EX-20 DSC

[Hans Verkuil <hverkuil@xs4all.nl>]

On 05/29/2014 08:23 PM, Richie Gress wrote:
> 
>> Date: Wed, 28 May 2014 10:56:51 +0200
>> From: hverkuil@xs4all.nl
>> To: searchfgold67899@live.com; linux-usb@vger.kernel.org; linux-media@vger.kernel.org
>> Subject: Re: 1d6b:0001 [MSI A55M-P33] No webcam functionality with Zoran Microelectronics, Ltd Digital Camera EX-20 DSC
>>
>> On 05/27/14 19:55, Richie Gress wrote:
>>>
>>>
>>>> Date: Tue, 27 May 2014 09:03:33 +0200
>>>> From: hverkuil@xs4all.nl
>>>> To: searchfgold67899@live.com; linux-usb@vger.kernel.org; linux-media@vger.kernel.org
>>>> Subject: Re: 1d6b:0001 [MSI A55M-P33] No webcam functionality with Zoran Microelectronics, Ltd Digital Camera EX-20 DSC
>>>>
>>>> On 05/27/2014 03:34 AM, Richie wrote:
>>>>> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1322380
>>>>>
>>>>> [1.] One line summary of the problem:
>>>>>
>>>>> 1d6b:0001 [MSI A55M-P33] No webcam functionality with Zoran Microelectronics,
>>>>> Ltd Digital Camera EX-20 DSC
>>>>>
>>>>> [2.] Full description of the problem/report:
>>>>>
>>>>> No software recognizes the webcam and this is not a regression. dmesg reports
>>>>> the following additional output after plugging the camera. You can see where I
>>>>> change the camera to "PC Mode" (in order to use the webcam, users must do this
>>>>> from the camera) at [ 691.147589]. The device is turned off at [ 1094.746444]:
>>>>>
>>>>> [ 688.796908] usb 4-2: new full-speed USB device number 2 using ohci-pci
>>>>> [ 688.965802] usb 4-2: New USB device found, idVendor=0595, idProduct=2002
>>>>> [ 688.965807] usb 4-2: New USB device strings: Mfr=4, Product=5,
>>>>> SerialNumber=6
>>>>> [ 688.965809] usb 4-2: Product: COACH DSC
>>>>> [ 688.965811] usb 4-2: Manufacturer: ZORAN
>>>>> [ 688.965813] usb 4-2: SerialNumber: ZORAN01234567
>>>>> [ 689.012630] usb-storage 4-2:1.0: USB Mass Storage device detected
>>>>> [ 689.021168] scsi6 : usb-storage 4-2:1.0
>>>>> [ 689.021266] usbcore: registered new interface driver usb-storage
>>>>> [ 690.030971] scsi 6:0:0:0: Direct-Access ZORAN COACH6 (I62) 1.10 PQ: 0 ANSI:
>>>>> 0 CCS
>>>>> [ 690.036147] sd 6:0:0:0: Attached scsi generic sg3 type 0
>>>>> [ 690.044964] sd 6:0:0:0: [sdc] 3962629 512-byte logical blocks: (2.02 GB/1.88
>>>>> GiB)
>>>>> [ 690.054977] sd 6:0:0:0: [sdc] Write Protect is off
>>>>> [ 690.054984] sd 6:0:0:0: [sdc] Mode Sense: 00 06 00 00
>>>>> [ 690.064965] sd 6:0:0:0: [sdc] No Caching mode page found
>>>>> [ 690.064971] sd 6:0:0:0: [sdc] Assuming drive cache: write through
>>>>> [ 690.108960] sd 6:0:0:0: [sdc] No Caching mode page found
>>>>> [ 690.108966] sd 6:0:0:0: [sdc] Assuming drive cache: write through
>>>>> [ 690.156970] sdc:
>>>>> [ 690.210974] sd 6:0:0:0: [sdc] No Caching mode page found
>>>>> [ 690.210980] sd 6:0:0:0: [sdc] Assuming drive cache: write through
>>>>> [ 690.210985] sd 6:0:0:0: [sdc] Attached SCSI removable disk
>>>>> [ 691.147589] usb 4-2: USB disconnect, device number 2
>>>>> [ 691.793364] usb 4-2: new full-speed USB device number 3 using ohci-pci
>>>>> [ 691.962202] usb 4-2: New USB device found, idVendor=0595, idProduct=4343
>>>>> [ 691.962207] usb 4-2: New USB device strings: Mfr=7, Product=8,
>>>>> SerialNumber=9
>>>>> [ 691.962209] usb 4-2: Product: COACH DSC
>>>>> [ 691.962211] usb 4-2: Manufacturer: ZORAN
>>>>> [ 691.962213] usb 4-2: SerialNumber: ZORAN00000001
>>>>> [ 691.964262] usb-storage 4-2:1.0: USB Mass Storage device detected
>>>>> [ 691.965410] usb-storage: probe of 4-2:1.0 failed with error -5
>>>>> [ 692.053929] Linux video capture interface: v2.00
>>>>> [ 692.091447] zr364xx 4-2:1.0: Zoran 364xx compatible webcam plugged
>>>>> [ 692.091453] zr364xx 4-2:1.0: model 0595:4343 detected
>>>>> [ 692.091461] usb 4-2: 320x240 mode selected
>>>>> [ 692.094356] usb 4-2: Zoran 364xx controlling device video0
>>>>
>>>> Clearly the webcam is recognized and a /dev/video0 node is created.
>>>> Please check that /dev/video0 exists. Try e.g. v4l2-ctl -D -d /dev/video0,
>>>> it should list it as using the zr364xx driver.
>>>>
>>>> So what exactly doesn't work?
>>>>
>>>> Regards,
>>>>
>>>> Hans
>>>>
>>>>> [ 692.094672] usbcore: registered new interface driver zr364xx
>>>>> [ 1094.746444] hub 4-0:1.0: port 2 disabled by hub (EMI?), re-enabling...
>>>>> [ 1094.746451] usb 4-2: USB disconnect, device number 3
>>>>> [ 1094.747395] zr364xx 4-2:1.0: Zoran 364xx webcam unplugged
>>>>
>>>
>>> Yes, it does seem to be using the zr364xx driver:
>>>
>>> $ v4l2-ctl -D -d /dev/video0
>>> Driver Info (not using libv4l2):
>>> Driver name : Zoran 364xx
>>> Card type : COACH DSC
>>> Bus info : 4-1
>>> Driver version: 3.15.0
>>> Capabilities : 0x85000001
>>> Video Capture
>>> Read/Write
>>> Streaming
>>> Device Capabilities
>>> Device Caps : 0x05000001
>>> Video Capture
>>> Read/Write
>>> Streaming
>>>
>>> The exact problem is that while the camera is recognized as a camera by software like Skype, Kamoso, and Cheese, there is no picture, just black. A "320x240 mode" was mentioned... perhaps that resolution is just too small to use by the software?
>>
>> Try using qv4l2. If that doesn't work, then it is likely to be a driver issue.
>> I have one zr364xx based camera and I can try it tomorrow or during the weekend.
>> It used to work, but it's been a long time since I tried it. On the other hand,
>> nobody did any work on that driver for a long time.
>>
>> Regards,
>>
>> Hans
> 
> It does smell like a driver issue, as you say. qv4l2 give me this output in the terminal and a blank window for the picture:

OK, this driver is pretty fragile. I had a lot of problems trying to get my
device to work. Lots of timeouts, etc. In the end I discovered that disabling
the re-initialization when the filehandle is closed solved those timeouts.

Here is a quick-and-dirty patch for you to try:

diff --git a/drivers/media/usb/zr364xx/zr364xx.c b/drivers/media/usb/zr364xx/zr364xx.c
index 9543c02..232443b 100644
--- a/drivers/media/usb/zr364xx/zr364xx.c
+++ b/drivers/media/usb/zr364xx/zr364xx.c
@@ -1255,6 +1255,7 @@ static int zr364xx_close(struct file *file)
 			zr364xx_stop_acquire(cam);
 		videobuf_streamoff(&cam->vb_vidq);
 
+		if (0)
 		for (i = 0; i < 2; i++) {
 			send_control_msg(udev, 1, init[cam->method][i].value,
 					0, init[cam->method][i].bytes,


After this change the driver behaves correctly for me.

If it still doesn't work for you after applying this change, then you should
try to experiment with the 'method'. The device_table array has the list of
all supported USB devices. The driver_info field tells the driver which
initialization sequence to use. Currently that is METHOD0 for your device.
Try changing that to methods 1-3 and see if one of them works.

But frankly, buying a new uvc-based webcam seems much more sensible to me...

Regards,

	Hans