Re: [PATCH 2/9] usb: dwc3: core: Allow glue layer to pass reference clock

From: Krzysztof Kozlowski

Date: Sun Aug 30 2026 - 05:43:18 EST


On Tue, Aug 25, 2026 at 02:42:27PM +0400, George Moussalem wrote:
> Add ability to pass a reference clock from the glue layer to the DWC3
> core driver. The core calculates the reference clock period and frame
> length adjustment based on the reference clock rate.
>
> In the flattened snsp-dwc3 model, it is currently not possible to pass a
> reference clock that differs from the default since:
> commit 613a2e655d4d ("usb: dwc3: core: Expose core driver as library")
>
> The new glue layers (incl. Qualcomm's) set the ignore_clocks_and_resets
> flag in dwc3_probe_data to true, which disables the core driver's clock
> management, thus it also doesn't acquire the reference clock from the
> devicetree needed in dwc3_ref_clk_period.
>
> There's an existing DT property 'snps,quirk-ref-clk-period-ns', but

Where? git grep gave me zero results.

Best regards,
Krzysztof