Webcam works only once after boot or wakeup

[pgh550]

I have an irritating problem with my Dell XPS 13 9343 running macOS Sierra 10.12.4. The webcam work once after every boot or wake-up. After a fresh boot or wake-up, the webcam works fine with Photo Booth app. After I quite Photo Booth app and reopen it, the app show a black window instead of the picture/ I checked with IORegistryExplorer, the entries under webcam HD seem identical in both situations.

I attached the ioreg 2.1 dumps here. Can someone, especially Rehabman, take a look and see what goes wrong after the 1st usage? Generally what would be a goof way to "diff" the ioreg files?

 

[RehabMan]

I have an irritating problem with my Dell XPS 13 9343 running macOS Sierra 10.12.4. The webcam work once after every boot or wake-up. After a fresh boot or wake-up, the webcam works fine with Photo Booth app. After I quite Photo Booth app and reopen it, the app show a black window instead of the picture/ I checked with IORegistryExplorer, the entries under webcam HD seem identical in both situations.

I attached the ioreg 2.1 dumps here. Can someone, especially Rehabman, take a look and see what goes wrong after the 1st usage? Generally what would be a goof way to "diff" the ioreg files?

USB is not implemented correctly.
See FAQ for link to guide...

 

[pgh550]

USB is not implemented correctly.
See FAQ for link to guide...

I checked the guide and I did not rename EHC1 to EH01. After did the renaming, the webcam still behaves the same, even though IORegistryExplorer shows that it is EH01 with ports PR11 to PR18 and webcam on PR11 (used to be EHC1 with PR01 and PR02, webcam was on PR01). There was not EH02 shown up.

I also re-patched the DSDT file and found out there is no ports attached to EH01 without the IRQ fix.

Rehabman, please take a look at attached the new IOReg file here and give me a pointer on how to fix the issue. Many thanks in advance.

 

[RehabMan]

I checked the guide and I did not rename EHC1 to EH01. After did the renaming, the webcam still behaves the same, even though IORegistryExplorer shows that it is EH01 with ports PR11 to PR18 and webcam on PR11 (used to be EHC1 with PR01 and PR02, webcam was on PR01). There was not EH02 shown up.

I also re-patched the DSDT file and found out there is no ports attached to EH01 without the IRQ fix.

Rehabman, please take a look at attached the new IOReg file here and give me a pointer on how to fix the issue. Many thanks in advance.

IRQ Fix is often needed with certain older hardware to enable EHCI..
Your camera problem is probably just an incompatibility with the camera itself.
You might try the UVCCameraControl app to see if it helps...

 

[pgh550]

Tried UVCCameraControl app, still the same. Realized that this webcam does not have a serial number. Could it still be the problem?

 

[RehabMan]

Tried UVCCameraControl app, still the same. Realized that this webcam does not have a serial number. Could it still be the problem?

Cameras that don't show serial# tend to be problematic.