[PATCH v1 2/6] drivers: usb: dwc3: Add delay after core soft reset

[Marek Vasut]

On 11/19/25 4:25 PM, Balaji Selvanathan wrote:
> Add a 100 ms delay after clearing the core soft reset bit to ensure
> the DWC3 controller has sufficient time to complete its reset
> sequence before subsequent register accesses.
> 
> Without this delay, USB initialization can fail on some Qualcomm
> platforms, particularly when using super-speed capable PHYs like
> the QMP USB3-DP Combo PHY on SC7280/QCM6490.
> 
> The change is taken from following upstream Linux implementation:
> https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/usb/dwc3/core.c?id=3d25d46a255a83f94d7d4d4216f38aafc8e116b0

Is this the correct commit ?

3d25d46a255a ("pmdomain: qcom: rpmhpd: Add rpmhpd support for SM8750")

It seems it is not, so which commit added that 100ms delay to Linux ?

> Signed-off-by: Balaji Selvanathan <balaji.selvanathan at oss.qualcomm.com>
> ---
>   drivers/usb/dwc3/core.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 847fa1f82c3..ff0bca0dd8e 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -94,6 +94,8 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc)
>   	reg &= ~DWC3_GCTL_CORESOFTRESET;
>   	dwc3_writel(dwc->regs, DWC3_GCTL, reg);
>   
> +	mdelay(100);
> +
Is this DWC3 specific or QCOM specific delay ?