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

Stefan Wahren
2024-07-05T15:21:34Z

Hi Jeremy,

Am 05.07.24 um 17:03 schrieb Lukas Wunner:
> On Fri, Jul 05, 2024 at 12:22:33PM +0200, Stefan Wahren wrote:
>> Am 05.07.24 um 10:48 schrieb Lukas Wunner:
>>> The real question is whether BCM2848 platforms likewise cannot disable
>>> the clock of the dwc2 controller or whether this is specific to the
>>> BCM2835. Right now dwc2_set_bcm_params() is applied to both the
>>> BCM2848 and BCM2835. If the BCM2848 behaves differently in this
>>> regard, we'd have to duplicate dwc2_set_bcm_params() for the BCM2835.
>> From my understand BCM2848 refers to the same SoC, but the ACPI
>> implementation uses a different ID [2]. So I think this is safe.
>> [2] -
>> https://patches.linaro.org/project/linux-usb/patch/20210413215834.3126447-2-jeremy.linton@arm.com/
> 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).
could you please clarify this situation?

Thanks
>
> Thanks,
>
> Lukas