[v2] usb: dwc3: core: Add quirk for enabling AutoRetry feature in the controller

[Felipe Balbi <balbi@kernel.org>]

Hi,

Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com> writes:
> By default when core sees any transaction error(CRC or overflow)
> it replies with terminating retry ACK (Retry=1 and Nump == 0).
> Enabling this Auto Retry feature in controller, on seeing any
> transaction errors makes the core to send a non-terminating ACK
> transaction packet (that is, ACK TP with Retry=1 and Nump != 0).
> Doing so will give controller a chance to recover from the error
> condition.
>
> Signed-off-by: Anurag Kumar Vulisha <anurag.kumar.vulisha@xilinx.com>
> ---
>  Changes in v2:
> 	1. As suggested by Rob Herring & Felipe Balbi removed the
> 	   quirk logic and setting the AutoRetry bits unconditionally
> 	   for hostmode
> ---
>  drivers/usb/dwc3/core.c | 14 ++++++++++++++
>  drivers/usb/dwc3/core.h |  3 +++
>  2 files changed, 17 insertions(+)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 1038075..478c8a6 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -883,6 +883,20 @@ static int dwc3_core_init(struct dwc3 *dwc)
>  		dwc3_writel(dwc->regs, DWC3_GUCTL1, reg);
>  	}
>  
> +	if (dwc->dr_mode == USB_DR_MODE_HOST) {

almost there. You also wanna check for dr_mode == OTG. OTG
configurations can switch between device and host mode at will.

> +		reg = dwc3_readl(dwc->regs, DWC3_GUCTL);
> +
> +		/* Enable Auto retry Feature to make the controller operating in

match the multi-line comment style already in this file:

	/*
         * Enable Auto ....