Re: [PATCH v7 1/5] usb: dwc3: host: Set PHY mode during suspend

From: Felipe Balbi <balbi@kernel.org>
To: Matthias Kaehlcke <mka@chromium.org>
Cc: Sandeep Maheswaram <sanm@codeaurora.org>,
	Andy Gross <agross@kernel.org>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Stephen Boyd <swboyd@chromium.org>,
	Doug Anderson <dianders@chromium.org>,
	linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Manu Gautam <mgautam@codeaurora.org>
Subject: Re: [PATCH v7 1/5] usb: dwc3: host: Set PHY mode during suspend
Date: Thu, 13 May 2021 16:46:41 +0300	[thread overview]
Message-ID: <87wns27nlq.fsf@kernel.org> (raw)
In-Reply-To: <YJwommGqKVeMdXth@google.com>

[-- Attachment #1: Type: text/plain, Size: 1087 bytes --]


Hi,

Matthias Kaehlcke <mka@chromium.org> writes:
>> > @@ -127,6 +142,50 @@ int dwc3_host_init(struct dwc3 *dwc)
>> >  	return ret;
>> >  }
>> >  
>> > +static void dwc3_set_phy_mode(struct usb_hcd *hcd)
>> > +{
>> > +
>> > +	int i, num_ports;
>> > +	u32 reg;
>> > +	unsigned int ss_phy_mode = 0;
>> > +	struct dwc3 *dwc = dev_get_drvdata(hcd->self.controller->parent);
>> > +	struct xhci_hcd	*xhci_hcd = hcd_to_xhci(hcd);
>> > +
>> > +	dwc->hs_phy_mode = 0;
>> > +
>> > +	reg = readl(&xhci_hcd->cap_regs->hcs_params1);
>> > +	num_ports = HCS_MAX_PORTS(reg);
>> 
>> there's a big assumption here that xhci is still alive. Why isn't this
>> quirk implemented in xhci-plat itself?
>
> That should work for determining which types of devices are connected to
> the PHYs, however IIUC the xhci-plat doesn't know about the PHY topology.
> Are you suggesting to move that info into the xhci-plat driver so that it
> can set the corresponding PHY modes?

Yes, if xHCI needs to know about PHYs in order to properly configure the
PHYs, so be it :-)

-- 
balbi

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 511 bytes --]