Re: [PATCH] usb: dwc3: gadget: call gadget driver's ->suspend/->resume

From: Felipe Balbi
Date: Fri Apr 24 2015 - 15:50:00 EST


Hi,

On Thu, Apr 23, 2015 at 03:37:48PM -0700, David Cohen wrote:
> On Fri, Apr 17, 2015 at 02:43:27PM -0500, Felipe Balbi wrote:
> > On Fri, Apr 17, 2015 at 11:41:56AM -0700, David Cohen wrote:
> > > From: Felipe Balbi <balbi@xxxxxx>
> >
> > missing the required:
> >
> > [ Upstream commit bc5ba2e0b829c9397f96df1191c7d2319ebc36d9 ]
> >
> > >
> > > When going into bus suspend/resume we _must_
> > > call gadget driver's ->suspend/->resume callbacks
> > > accordingly. This patch implements that very feature
> > > which has been missing forever.
> > >
> > > Cc: <stable@xxxxxxxxxxxxxxx> # 3.14
> > > Signed-off-by: Felipe Balbi <balbi@xxxxxx>
> > > Signed-off-by: David Cohen <david.a.cohen@xxxxxxxxxxxxxxx>
> > > ---
> > >
> > > Hi,
> > >
> > > This patch was introduced on v3.15.
> > > But the issue it fixes already existed on v3.14 and v3.14 is a long term
> > > support version.
> >
> > Can you show me a log of this breaking anywhere ? Why do you consider
> > this a bug fix ? What sort of drawbacks did you notice ?
>
> We're seeing BC1.2 compliance test failure. I borrowed this info from
> the bug report :)
>
> 1. BC1.2 compliance testing - SDP2.0
> -----------------------------------------------
> 1. On Connect to active Host (Expected result: 100mA to 500mA):
> Actual result 100mA to 500mA
>
> 2. On Host Suspend (ER: Fall back to 0mA):
> not falling back to 0mA, remains at 500mA
>
> 3. On Connect to Suspended Host (ER: 100mA to 0mA):
> cable-props shown as 100mA, which means drawing a current of 100mA from
> Suspended Host
>
> 4. On making Host active (ER: 500mA):
> 500mA

But we don't support Battery Charging with dwc3 as of now :-) In fact,
just note that none of the BC registers are even defined in the current
driver anywhere. Seems like you should cherry-pick these to your vendor
tree, but v3.14 vanilla, because it doesn't support BC1.2, can't be
claimed to be at fault, right ?

I'll leave the final decision to Greg and I don't really oppose having
both patches on v3.14-stable, but this is not a bug fix in my view.

--
balbi

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