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ID conflict between bdc_pci and "720p FaceTime HD Camera"

DISCUSSION Xavier Gnata 2 participants 3 messages Jan 17, 2016 – Jan 19, 2016 PCI

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Hello,

The development of a driver for
02:00.0 Multimedia controller [0480]: Broadcom Corporation 720p FaceTime HD Camera [14e4:1570] has started. It is still in an early stage but it's progressing and it already streams.
https://github.com/patjak/bcwc_pcie

However, as you can see, this webcam shares the exact same ID as bdc_pci 0x1570 .

Could we use e.g. PCI_CLASS in bdc_pci to avoid grabbing the webcam incorrectly? The FaceTime HD Camera has PCI_CLASS 0x048000
I hope that bdc_pci has another PCI_CLASS.
Or maybe there is a better way to distinguish bdc_pci from FaceTime HD Camera. What do you think?

Regards,
Xavier

#1 lore raw

[+cc Ashwini, Felipe]

Quoted 12 lines · Xavier Gnata

Hello,

The development of a driver for
02:00.0 Multimedia controller [0480]: Broadcom Corporation 720p FaceTime HD Camera [14e4:1570]
has started. It is still in an early stage but it's progressing and it already streams.
https://github.com/patjak/bcwc_pcie

However, as you can see, this webcam shares the exact same ID as bdc_pci 0x1570 .

Quoted 6 lines

Could we use e.g. PCI_CLASS in bdc_pci to avoid grabbing the webcam incorrectly?
The FaceTime HD Camera has PCI_CLASS 0x048000
I hope that bdc_pci has another PCI_CLASS.
Or maybe there is a better way to distinguish bdc_pci from FaceTime HD Camera. What do you think?

This is what the PCI Vendor/Device IDs are for. It's a shame that Broadcom apparently screwed up and used the same IDs in two different devices.

At least, I *assume* they're different. I can't really tell what the bdc_pci driver does, so it's conceivable that it's using the same device in a different way than you are.

If they really are different devices, using the class code sounds like a reasonable way to differentiate them.

Bjorn

#2 lore raw
Quoted 26 lines · Bjorn Helgaas

[+cc Ashwini, Felipe]

Quoted 12 lines · Xavier Gnata

Hello,

The development of a driver for
02:00.0 Multimedia controller [0480]: Broadcom Corporation 720p FaceTime HD Camera [14e4:1570]
has started. It is still in an early stage but it's progressing and it already streams.
https://github.com/patjak/bcwc_pcie

However, as you can see, this webcam shares the exact same ID as bdc_pci 0x1570 .

Quoted 6 lines

Could we use e.g. PCI_CLASS in bdc_pci to avoid grabbing the webcam incorrectly?
The FaceTime HD Camera has PCI_CLASS 0x048000
I hope that bdc_pci has another PCI_CLASS.
Or maybe there is a better way to distinguish bdc_pci from FaceTime HD Camera. What do you think?

This is what the PCI Vendor/Device IDs are for. It's a shame that Broadcom apparently screwed up and used the same IDs in two different devices.

Quoted 9 lines

At least, I *assume* they're different. I can't really tell what the bdc_pci driver does, so it's conceivable that it's using the same device in a different way than you are.

If they really are different devices, using the class code sounds like a reasonable way to differentiate them.

Bjorn

bdc is "Broadcom's USB3.0 device controller IP" in the SOC world which is connected through PCIe on FPGA-PCIe based platform. Nothing to do with the Facetime HD webcam of a macbook air.
Broadcom screwed up.

The issue is that I don't have access to such a BDC. I also don't find it in
http://pcidatabase.com/vendor_details.php?id=767
which lists 0x1570 as being the webcam.

Where can we find the PCI class of this "Broadcom's USB3.0 device controller IP" ? Ashwini?

Xavier