usb: gadget: composite: Return bcdUSB 0x0310
Hi,
I'd like to request the following be applied to stable trees 3.2+.
1a85329171094951956a37acc8abb7e51c1e742e ("usb: gadget: composite:
Return bcdUSB 0x0310")
The USB 3.1 specification replaces the USB 3.0 specification and all new devices that are running at SuperSpeed or higher speeds must report a bcdUSB of 0x0310.
Thanks,
John
Greg Kroah-Hartman
maintainerQuoted 10 lines · John Youn
Hi,
I'd like to request the following be applied to stable trees 3.2+.
1a85329171094951956a37acc8abb7e51c1e742e("usb: gadget: composite:
Return bcdUSB0x0310")The USB 3.1 specification replaces the USB 3.0 specification and all new devices that are running at SuperSpeed or higher speeds must report a bcdUSB of
0x0310.
That doesn't seem very "backwards compatible" of the spec to me, what happens if you return a 3.0 string, when you really are only handling 3.0 things like we do in older kernels?
thanks,
greg k-h
Quoted 12 lines · Greg Kroah-Hartman
Quoted 10 lines · John Youn
Hi,
I'd like to request the following be applied to stable trees 3.2+.
1a85329171094951956a37acc8abb7e51c1e742e("usb: gadget: composite:
Return bcdUSB0x0310")The USB 3.1 specification replaces the USB 3.0 specification and all new devices that are running at SuperSpeed or higher speeds must report a bcdUSB of
0x0310.
Quoted 8 lines
That doesn't seem very "backwards compatible" of the spec to me, what happens if you return a 3.0 string, when you really are only handling 3.0 things like we do in older kernels?
thanks,
greg k-h
Hi Greg,
I believe there would be no backward-incompatible change as all 3.0 things are now part of the 3.1 spec, and the new stuff in 3.1 (such as SuperSpeedPlus) are exposed through new descriptors. And I don't believe anything currently looks at bcdUSB 3.0 vs 3.1 (unlike with USB 2.x). But I can't say for sure.
This is only needed because the CV tool has started requiring this and I believe the compliance process will also start requiring it for all new devices. We plan to certify new devices with kernels as old as 3.18, hence this backport.
If you like, I can solicit comments on this from the linux-usb list.
Thanks,
John
Greg Kroah-Hartman
maintainerQuoted 30 lines · John Youn
Quoted 12 lines · Greg Kroah-Hartman
Quoted 10 lines · John Youn
Hi,
I'd like to request the following be applied to stable trees 3.2+.
1a85329171094951956a37acc8abb7e51c1e742e("usb: gadget: composite:
Return bcdUSB0x0310")The USB 3.1 specification replaces the USB 3.0 specification and all new devices that are running at SuperSpeed or higher speeds must report a bcdUSB of
0x0310.Quoted 8 lines
That doesn't seem very "backwards compatible" of the spec to me, what happens if you return a 3.0 string, when you really are only handling 3.0 things like we do in older kernels?
thanks,
greg k-h
Hi Greg,
I believe there would be no backward-incompatible change as all 3.0 things are now part of the 3.1 spec, and the new stuff in 3.1 (such as SuperSpeedPlus) are exposed through new descriptors. And I don't believe anything currently looks at bcdUSB 3.0 vs 3.1 (unlike with USB 2.x). But I can't say for sure.
Quoted 4 lines
This is only needed because the CV tool has started requiring this and I believe the compliance process will also start requiring it for all new devices. We plan to certify new devices with kernels as old as 3.18, hence this backport.
For "new" devices, why are you using such an old and obsolete kernel as 3.18?
For an "old" device, a bcdUSB of 3.0 should just be fine, right?
Quoted 1 line
If you like, I can solicit comments on this from the linux-usb list.
Please do, you need the maintainer of the subsystem to agree to this at the least :)
thanks,
greg k-h