Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Sat, 14 May 2022 14:05:18 -0700
From:   Nathan Chancellor <nathan@kernel.org>
To:     Wolfram Sang <wsa@kernel.org>
Cc:     Codrin Ciubotariu <codrin.ciubotariu@microchip.com>,
        Nicolas Ferre <nicolas.ferre@microchip.com>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>,
        Claudiu Beznea <claudiu.beznea@microchip.com>,
        Michael Walle <michael@walle.cc>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-i2c@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        llvm@lists.linux.dev
Subject: Re: [PATCH] i2c: at91: Initialize dma_buf in at91_twi_xfer()
Message-ID: <YoAZjpzAEugCiv/Q@dev-arch.thelio-3990X>
References: <20220505152738.1440249-1-nathan@kernel.org>
 <Yn+xsNqFyRMTu+5X@shikoro>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <Yn+xsNqFyRMTu+5X@shikoro>
Precedence: bulk

On Sat, May 14, 2022 at 03:42:08PM +0200, Wolfram Sang wrote:
> On Thu, May 05, 2022 at 08:27:38AM -0700, Nathan Chancellor wrote:
> > Clang warns:
> > 
> >   drivers/i2c/busses/i2c-at91-master.c:707:6: warning: variable 'dma_buf' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
> >           if (dev->use_dma) {
> >               ^~~~~~~~~~~~
> >   drivers/i2c/busses/i2c-at91-master.c:717:27: note: uninitialized use occurs here
> >           i2c_put_dma_safe_msg_buf(dma_buf, m_start, !ret);
> >                                    ^~~~~~~
> > 
> > Initialize dma_buf to NULL, as i2c_put_dma_safe_msg_buf() is a no-op
> > when the first argument is NULL, which will work for the !dev->use_dma
> > case.
> > 
> > Fixes: 03fbb903c8bf ("i2c: at91: use dma safe buffers")
> > Link: https://github.com/ClangBuiltLinux/linux/issues/1629
> > Signed-off-by: Nathan Chancellor <nathan@kernel.org>
> 
> Applied to for-next, thanks!
> 

Thank you!

Cheers,
Nathan