Re: [PATCH 2/2] usb: dwc3: Add workaround for host mode VBUS glitch when boot

From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
To: Frank Li <Frank.Li@nxp.com>
Cc: "ran.wang_1@nxp.com" <ran.wang_1@nxp.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"open list:DESIGNWARE USB3 DRD IP DRIVER"
	<linux-usb@vger.kernel.org>,
	open list <linux-kernel@vger.kernel.org>,
	"balbi@kernel.org" <balbi@kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"mark.rutland@arm.com" <mark.rutland@arm.com>,
	"pku.leo@gmail.com" <pku.leo@gmail.com>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"sergei.shtylyov@cogentembedded.com"
	<sergei.shtylyov@cogentembedded.com>
Subject: Re: [PATCH 2/2] usb: dwc3: Add workaround for host mode VBUS glitch when boot
Date: Sat, 20 Jan 2024 00:55:54 +0000	[thread overview]
Message-ID: <20240120005552.pxlofaaoovxjt2oj@synopsys.com> (raw)
In-Reply-To: <20240120005056.o52hqn2sershhm76@synopsys.com>

On Sat, Jan 20, 2024, Thinh Nguyen wrote:
> > +
> >  static int dwc3_host_get_irq(struct dwc3 *dwc)
> >  {
> >  	struct platform_device	*dwc3_pdev = to_platform_device(dwc->dev);
> > @@ -66,6 +105,13 @@ int dwc3_host_init(struct dwc3 *dwc)
> >  	int			ret, irq;
> >  	int			prop_idx = 0;
> >  
> > +	/*
> > +	 * We have to power off all Root hub ports immediately after DWC3 set
> > +	 * to host mode to avoid VBUS glitch happen when xhci get reset later.
> > +	 */
> > +	if (dwc->host_vbus_glitches)
> > +		dwc3_power_off_all_roothub_ports(dwc);
> > +
> 
> It's part of the dwc3_host_init(), but don't do this in
> dwc3_host_get_irq(). Place it where it makes sense.

Ignore this comment, I thought it's called from dwc3_host_get_irq(), but
it's not.

BR,
Thinh

> 
> >  	irq = dwc3_host_get_irq(dwc);
> >  	if (irq < 0)
> >  		return irq;
> > -- 
> > 2.34.1
> > 
> 