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Date:   Mon, 17 Feb 2020 15:18:31 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc:     "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
        Timur Tabi <timur@kernel.org>, Li Yang <leoyang.li@nxp.com>,
        Anton Vorontsov <avorontsov@ru.mvista.com>,
        kbuild test robot <lkp@intel.com>, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org, Joe Perches <joe@perches.com>
Subject: Re: [PATCH] usb: host: fhci-hcd: annotate PIPE_CONTROL switch case
 with fallthrough
Message-ID: <20200217141831.GA1123892@kroah.com>
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On Mon, Feb 17, 2020 at 03:12:21PM +0100, Rasmus Villemoes wrote:
> On 17/02/2020 10.38, Greg Kroah-Hartman wrote:
> > On Thu, Feb 13, 2020 at 02:35:18PM +0100, Rasmus Villemoes wrote:
> >> On 13/02/2020 13.56, Greg Kroah-Hartman wrote:
> >>
> >>> Shouldn't this be /* fall through */ instead?
> >>>
> >>> Gustavo, what's the best practice here, I count only a few
> >>> "fallthrough;" instances in the kernel, although one is in our coding
> >>> style document, and thousands of the /* */ version.
> >>
> >> Yes, I went with the attribute/macro due to that, and the history is
> >> that Linus applied Joe's patches directly
> >> (https://lore.kernel.org/lkml/CAHk-=whOF8heTGz5tfzYUBp_UQQzSWNJ_50M7-ECXkfFRDQWFA@mail.gmail.com/),
> >> so I assumed that meant the Penguin decided that the attribute/macro is
> >> the right thing to do for new code, while existing comment annotations
> >> can be left alone or changed piecemeal as code gets refactored anyway.
> > 
> > But, to be fair, Gustavo went and fixed up thousands of these, with the
> > /* */ version, not the attribute.
> > 
> > Gustavo, can coverity notice the "fallthrough;" attribute properly?  I
> > don't want to start adding things that end up triggering
> > false-positives.
> 
> I'm not Gustavo, and I don't know the answer, but 1.5 years ago some guy
> named greg k-h suggested that coverity does grok the fallthrough attribute:
> 
> https://patchwork.kernel.org/cover/10651357/#22279095

I wouldn't trust anything that bum says :)

Ok, I don't remember saying that at all, but I'll wait a day or two to
get Gustavo's opinion befor applying the patch.

thanks,

greg k-h