From: Pavel Roskin <proski@gnu.org>
To: Michael Buesch <mb@bu3sch.de>
Cc: Larry Finger <Larry.Finger@lwfinger.net>,
John W Linville <linville@tuxdriver.com>,
bcm43xx-dev@lists.berlios.de, linux-wireless@vger.kernel.org
Subject: Re: [PATCH] b43: Fix sparse warnings
Date: Fri, 14 Aug 2009 16:52:13 -0400 [thread overview]
Message-ID: <1250283133.8137.16.camel@mj> (raw)
In-Reply-To: <200908142215.38112.mb@bu3sch.de>
On Fri, 2009-08-14 at 22:15 +0200, Michael Buesch wrote:
> > - b43_phy_mask(dev, 0x048A, (u16)~0x8000);
> > + b43_phy_mask(dev, 0x048A, (u16)(~0x8000 & 0xFFFF));
>
> Uh come on...
> The u16 cast already is stupid as hell, but this is becoming braindead.
> The code is perfectly fine. Sparse should instead provide an option to disable
> this fragile check.
There are cases where we want to know that a constant was truncated. In
fact, in most cases it's a useful warning.
In this case, we intuitively expect that it's OK to cast a result of a
bitwise operation to its original type, as if it was never promoted.
But sparse will need to have a special exception for this case.
I would just use 0x7fff here.
--
Regards,
Pavel Roskin
next prev parent reply other threads:[~2009-08-14 20:52 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-13 22:15 [PATCH] b43: Fix sparse warnings Larry Finger
2009-08-14 20:15 ` Michael Buesch
2009-08-14 20:52 ` Pavel Roskin [this message]
2009-08-14 21:00 ` Michael Buesch
2009-08-14 21:04 ` Gábor Stefanik
2009-08-14 21:35 ` Pavel Roskin
2009-08-15 10:04 ` Michael Buesch
2009-08-17 20:30 ` Pavel Roskin
2009-08-18 13:12 ` Michael Buesch
2009-08-14 21:29 ` Pavel Roskin
2009-08-14 21:46 ` Pavel Roskin
2009-08-15 10:08 ` Michael Buesch
2009-08-14 21:33 ` Larry Finger
-- strict thread matches above, loose matches on Subject: below --
2007-09-19 16:30 Michael Buesch
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