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

From: Dexuan Cui
Date: Mon Feb 02 2015 - 05:09:39 EST


> -----Original Message-----
> From: Jason Wang [mailto:jasowang@xxxxxxxxxx]
> Sent: Monday, February 2, 2015 17:36 PM
> To: Dexuan Cui
> Cc: gregkh@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; driverdev-
> devel@xxxxxxxxxxxxxxxxxxxxxx; olaf@xxxxxxxxx; apw@xxxxxxxxxxxxx; KY
> Srinivasan; vkuznets@xxxxxxxxxx; 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@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
> > Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> > Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> > ---
> >
> > 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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