Re: [PATCH 2/6] usb: dwc3: gadget: clear SUSPHY bit before ep cmds

[Mattijs Korpershoek <mkorpershoek@baylibre.com>]

Hi Alexander,

Thank you for the patch.

On ven., avril 12, 2024 at 22:26, "A. Sverdlin" <alexander.sverdlin@siemens.com> wrote:

> From: Felipe Balbi <felipe.balbi@linux.intel.com>
>
> Upstream Linux commit 2b0f11df84bb.
>
> Synopsys Databook 2.60a has a note that if we're
> sending an endpoint command we _must_ make sure that
> DWC3_GUSB2PHY(n).SUSPHY bit is cleared.
>
> This patch implements that particular detail.
>
> Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>

Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>

> ---
>  drivers/usb/dwc3/gadget.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 17c19285f1c24..8f6513752f085 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -302,8 +302,25 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
>  {
>  	u32			timeout = 500;
>  	u32			reg;
> +
> +	int			susphy = false;
>  	int			ret = -EINVAL;
>  
> +	/*
> +	 * Synopsys Databook 2.60a states, on section 6.3.2.5.[1-8], that if
> +	 * we're issuing an endpoint command, we must check if
> +	 * GUSB2PHYCFG.SUSPHY bit is set. If it is, then we need to clear it.
> +	 *
> +	 * We will also set SUSPHY bit to what it was before returning as stated
> +	 * by the same section on Synopsys databook.
> +	 */
> +	reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
> +	if (unlikely(reg & DWC3_GUSB2PHYCFG_SUSPHY)) {
> +		susphy = true;
> +		reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
> +		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
> +	}
> +
>  	dwc3_writel(dwc->regs, DWC3_DEPCMDPAR0(ep), params->param0);
>  	dwc3_writel(dwc->regs, DWC3_DEPCMDPAR1(ep), params->param1);
>  	dwc3_writel(dwc->regs, DWC3_DEPCMDPAR2(ep), params->param2);
> @@ -331,6 +348,12 @@ int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
>  		udelay(1);
>  	} while (1);
>  
> +	if (unlikely(susphy)) {
> +		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
> +		reg |= DWC3_GUSB2PHYCFG_SUSPHY;
> +		dwc3_writel(dwc->regs, DWC3_GUSB2PHYCFG(0), reg);
> +	}
> +
>  	return ret;
>  }
>  
> -- 
> 2.44.0