Re: [PATCH 09/11] usb: dwc2: Skip clock gating on Broadcom SoCs

Lukas Wunner
2024-07-05T21:14:23Z

On Fri, Jul 05, 2024 at 12:16:14PM -0500, Jeremy Linton wrote:
> > Am 05.07.24 um 17:03 schrieb Lukas Wunner:
> > > Careful there, the patch vaguely says...
> > >
> > > With that added and identified as "BCM2848",
> > > an id in use by other OSs for this device, the dw2
> > > controller on the BCM2711 will work.
> > >
> > > ...which sounds like they copy-pasted the BCM2848 id from somewhere else.
> > > I would assume that BCM2848 is really a different SoC and not just
> > > a different name for the BCM2835, but hopefully BroadCom folks will
> > > be able to confirm or deny this (and thus the necessity of the quirk
> > > on BCM2848 and not just on BCM2835).
>
> This id comes from the edk2-platforms ACPI tables and is currently used by
> both the rpi3 and rpi4, and AFAIK nothing else as the rpi5-dev work is
> currently only exposing XHCI.
>
> The ID is strictly the USB controller not the SoC. Its a bit confusingly
> named, but something we inherited from the much older windows/edk2 port,
> where it appears that the peripheral HID's were just picked in numerical
> order.
>
> [0] https://github.com/tianocore/edk2-platforms/blob/12f68d29abdc9d703f67bd743fdec23ebb1e966e/Platform/RaspberryPi/AcpiTables/GpuDevs.asl#L15

So BCM2848, BCM2849, BCM2850 and so on are just made-up IDs
for a Windows/EDK2 port that got cargo-culted into the kernel?
Yikes!

Has anyone checked whether they collide with actual Broadcom products?