Re: [PATCH v3 5/9] usb: gadget: s3c-hsotg: use generic phy_init()/phy_exit() support

From: Matt Porter <matt.porter@linaro.org>
To: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Felipe Balbi <balbi@ti.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Rob Herring <rob.herring@calxeda.com>,
	Pawel Moll <pawel.moll@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Kumar Gala <galak@codeaurora.org>,
	Ian Campbell <ijc+devicetree@hellion.org.uk>,
	Christian Daudt <bcm@fixthebug.org>,
	Paul Zimmerman <paulz@synopsys.com>,
	Tomasz Figa <t.figa@samsung.com>,
	Kamil Debski <k.debski@samsung.com>,
	Kyungmin Park <kyungmin.park@samsung.com>,
	Linux USB List <linux-usb@vger.kernel.org>,
	Linux ARM Kernel List <linux-arm-kernel@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Devicetree List <devicetree@vger.kernel.org>,
	Linaro Patches <patches@linaro.org>
Subject: Re: [PATCH v3 5/9] usb: gadget: s3c-hsotg: use generic phy_init()/phy_exit() support
Date: Thu, 28 Nov 2013 11:41:38 -0500	[thread overview]
Message-ID: <20131128164138.GS31091@beef> (raw)
In-Reply-To: <5296DA70.8010409@ti.com>

On Thu, Nov 28, 2013 at 11:23:52AM +0530, Kishon Vijay Abraham I wrote:
> On Thursday 28 November 2013 04:06 AM, Matt Porter wrote:
> > On Wed, Nov 27, 2013 at 12:13:25PM -0500, Matt Porter wrote:
> >> On Tue, Nov 26, 2013 at 03:53:32PM +0530, Kishon Vijay Abraham I wrote:
> >>> Hi,
> >>>
> >>> On Monday 25 November 2013 11:46 PM, Matt Porter wrote:
> >>>> If a generic phy is present, call phy_init()/phy_exit(). This supports
> >>>> generic phys that must be soft reset before power on.
> >>>>
> >>>> Signed-off-by: Matt Porter <matt.porter@linaro.org>
> >>>> ---
> >>>>  drivers/usb/gadget/s3c-hsotg.c | 5 +++++
> >>>>  1 file changed, 5 insertions(+)
> >>>>
> >>>> diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
> >>>> index da3879b..8dfe33f 100644
> >>>> --- a/drivers/usb/gadget/s3c-hsotg.c
> >>>> +++ b/drivers/usb/gadget/s3c-hsotg.c
> >>>> @@ -3622,6 +3622,9 @@ static int s3c_hsotg_probe(struct platform_device *pdev)
> >>>>  		goto err_supplies;
> >>>>  	}
> >>>>  
> >>>> +	if (hsotg->phy)
> >>>
> >>> IS_ERR? If your phy_get fails *phy* will have a error value..
> >>
> >> Yes, thanks. I'll fix these and also note that the same issue exists in
> >> Kamil's patch for these same hsotg->phy conditional uses. I'll work with
> >> Kamil to either get those addressed there or in a follow on fix.
> > 
> > I spoke too soon. If devm_phy_get fails, we don't set hsotg->phy and probe
> > defer thus not reaching this point. Since hsotg->phy is either NULL or a
> > valid struct phy *, this is correct as is throughout the driver.
> > 
> >>>
> >>>> +		phy_init(hsotg->phy);
> >>>> +
> >>>>  	/* usb phy enable */
> >>>>  	s3c_hsotg_phy_enable(hsotg);
> >>>>  
> >>>> @@ -3715,6 +3718,8 @@ static int s3c_hsotg_remove(struct platform_device *pdev)
> >>>>  	}
> >>>>  
> >>>>  	s3c_hsotg_phy_disable(hsotg);
> >>>> +	if (hsotg->phy)
> >>>
> >>> same here.
> >>
> >> Ok.
> > 
> > Same above, this will be NULL on failure (but is only applicable at this
> > point on the platform data path.
> 
> Ah ok.. Btw where is phy_get being called? Is it not part of this series?

It's in the Kamil's Exynos USB Phy -> generic phy series [1] which I depend
on here. I mentioned it in the cover letter toward the end so it's a bit
buried.

I have some outstanding, but trivial, comments on that series but I hear
Kamil will be posting an update in the coming days. I'll wait a few days
to post v4 addressing your comments so I can hopefully rebase against
his updated s3c-hsotg patch.

-Matt

[1] https://lkml.org/lkml/2013/11/5/275