Hi,
Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx> writes:
> From DWC_usb31 databook section 1.3.2, once DWC3_DCTL_CSFTRST bit is
> cleared, we must wait at least 50ms before accessing the PHY domain
> (synchronization delay).
>
> Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
> ---
> drivers/usb/dwc3/core.c | 13 ++++++++++++-
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 07832509584f..7d21f21707f5 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -228,12 +228,23 @@ static int dwc3_core_soft_reset(struct dwc3 *dwc)
> do {
> reg = dwc3_readl(dwc->regs, DWC3_DCTL);
> if (!(reg & DWC3_DCTL_CSFTRST))
> - return 0;
> + goto done;
>
> udelay(1);
> } while (--retries);
>
> return -ETIMEDOUT;
> +
> +done:
> + /*
> + * For DWC_usb31 controller, once DWC3_DCTL_CSFTRST bit is cleared,
> + * we must wait at least 50ms before accessing the PHY domain
> + * (synchronization delay). DWC_usb31 Databook section 1.3.2.
> + */
> + if (dwc3_is_usb31(dwc))
> + mdelay(50);
we don't have any locks held. Why are you busy looping for an entire
50ms? Why don't you msleep() here?
--
balbi
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