From: Hin-Tak Leung <htl10@users.sourceforge.net>
To: Kalle Valo <kvalo@codeaurora.org>
Cc: Herton Ronaldo Krzesinski <herton@canonical.com>,
Larry Finger <larry.finger@lwfinger.net>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
gregkh@linuxfoundation.org, Salah Triki <salah.triki@gmail.com>,
linux-wireless@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] wireless: rtl8187: replace udev with usb_get_dev()
Date: Tue, 27 Jul 2021 18:57:56 +0000 (UTC) [thread overview]
Message-ID: <1490129435.403938.1627412276697@mail.yahoo.com> (raw)
In-Reply-To: 1490129435.403938.1627412276697.ref@mail.yahoo.com
> > On Saturday, 24 July 2021, 19:35:12 BST, Salah Triki <salah.triki@gmail.com> wrote:
> >
> >> Replace udev with usb_get_dev() in order to make code cleaner.
> >
> >> Signed-off-by: Salah Triki <salah.triki@gmail.com>
Nacked-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Seeing as the change does not add any value.
> >> ---
> >> drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c | 4 +---
> >> 1 file changed, 1 insertion(+), 3 deletions(-)
> >
> >> diff --git a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
> > b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
> >> index eb68b2d3caa1..30bb3c2b8407 100644
> >> --- a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
> >> +++ b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
> >> @@ -1455,9 +1455,7 @@ static int rtl8187_probe(struct usb_interface *intf,
> >
> >> SET_IEEE80211_DEV(dev, &intf->dev);
> >> usb_set_intfdata(intf, dev);
> >> - priv->udev = udev;
> >> -
> >> - usb_get_dev(udev);
> >> + priv->udev = usb_get_dev(udev);
> >
> >> skb_queue_head_init(&priv->rx_queue);
> >
> >> --
> >> 2.25.1
> >
> > It is not cleaner - the change is not functionally equivalent. Before
> > the change, the reference count is increased after the assignment; and
> > after the change, before the assignment. So my question is, does the
> > reference count increasing a little earlier matters? What can go wrong
> > between very short time where the reference count increases, and
> > priv->udev not yet assigned? I think there might be a race condition
> > where the probbe function is called very shortly twice. Especially if
> > the time of running the reference count function is non-trivial.
> >
> > Larry, what do you think?
> BTW, please don't use HTML in emails. Our lists drop all HTML mail (and
for a good reason).
Yes, sorry about that (I got a few bounces). Yahoo (where this is coming from) seems to make it quite hard to send plain non-html e-mails. See if this one gets through.
> --
> https://patchwork.kernel.org/project/linux-wireless/list/
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
next parent reply other threads:[~2021-07-27 18:58 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1490129435.403938.1627412276697.ref@mail.yahoo.com>
2021-07-27 18:57 ` Hin-Tak Leung [this message]
2021-07-28 7:13 ` [PATCH] wireless: rtl8187: replace udev with usb_get_dev() Kalle Valo
2021-07-24 18:34 Salah Triki
[not found] ` <53895498.1259278.1627160074135@mail.yahoo.com>
2021-07-25 6:33 ` Greg KH
2021-07-25 19:46 ` Larry Finger
2021-07-27 6:10 ` Kalle Valo
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