RE: [PATCH v2 1/3] hv: hv_util: move vmbus_open() to a later place

[Dexuan Cui <decui@microsoft.com>]

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> -----Original Message-----
> From: Jason Wang [mailto:jasowang@redhat.com]
> Sent: Monday, February 2, 2015 17:36 PM
> To: Dexuan Cui
> Cc: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; driverdev-
> devel@linuxdriverproject.org; olaf@aepfle.de; apw@canonical.com; KY
> Srinivasan; vkuznets@redhat.com; Haiyang Zhang
> Subject: Re: [PATCH v2 1/3] hv: hv_util: move vmbus_open() to a later place
> 
> 
> 
> On Mon, Feb 2, 2015 at 12:35 PM, Dexuan Cui <decui@microsoft.com> wrote:
> > Before the line vmbus_open() returns, srv->util_cb can be already
> > running
> > and the variables, like util_fw_version, are needed by the
> > srv->util_cb.
> 
> A questions is why we do this for util only? Can callbacks of other
> devices be called before vmbus_open() returns?
The variables are used in vmbus_prep_negotiate_resp(), which is only for
the util devices.

I think the other devices should already handle the similar issue properly.
If this is not the case, we need to fix them too.

> 
> >
> > So we have to make sure the variables are initialized before the
> > vmbus_open().
> >
> > CC: "K. Y. Srinivasan" <kys@microsoft.com>
> > Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> > Signed-off-by: Dexuan Cui <decui@microsoft.com>
> > ---
> >
> > v2:
> > This is a RESEND.
> > I just added Vitaly's Reviewed-by.
> >
> >  drivers/hv/hv_util.c | 11 ++++++-----
> >  1 file changed, 6 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
> > index 3b9c9ef..c5be773 100644
> > --- a/drivers/hv/hv_util.c
> > +++ b/drivers/hv/hv_util.c
> > @@ -340,12 +340,8 @@ static int util_probe(struct hv_device *dev,
> >
> >  	set_channel_read_state(dev->channel, false);
> >
> > -	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL,
> > 0,
> > -			srv->util_cb, dev->channel);
> > -	if (ret)
> > -		goto error;
> > -
> >  	hv_set_drvdata(dev, srv);
> > +
> 
> This seems unnecessary.
Yeah, it's an empty line, splitting the line and the below comment.
I'm Ok to not have it.

> >  	/*
> >  	 * Based on the host; initialize the framework and
> >  	 * service version numbers we will negotiate.
> > @@ -365,6 +361,11 @@ static int util_probe(struct hv_device *dev,
> >  		hb_srv_version = HB_VERSION;
> >  	}
> >
> > +	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL,
> > 0,
> > +			srv->util_cb, dev->channel);
> > +	if (ret)
> > +		goto error;
> > +
> >  	return 0;
> >
> >  error:
> > --
> > 1.9.1
> >

-- Dexuan
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