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Fri, 16 Feb 2024 15:11:46 -0500 (EST) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.11.0-alpha0-144-ge5821d614e-fm-20240125.002-ge5821d61 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <025f63f5-9114-439b-ad49-c37dffd1ea2f@app.fastmail.com> In-Reply-To: References: <20240216163201.1901744-1-arnd@kernel.org> Date: Fri, 16 Feb 2024 21:11:25 +0100 From: "Arnd Bergmann" To: "Justin Stitt" , "Arnd Bergmann" Cc: "Mauro Carvalho Chehab" , "Hans Verkuil" , "laurent.pinchart" , "Nathan Chancellor" , "Nick Desaulniers" , "Bill Wendling" , "Mark Brown" , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH] media: dvb-frontends: avoid stack overflow warnings with clang Content-Type: text/plain;charset=utf-8 Content-Transfer-Encoding: quoted-printable On Fri, Feb 16, 2024, at 19:56, Justin Stitt wrote: > On Fri, Feb 16, 2024 at 8:32=E2=80=AFAM Arnd Bergmann wrote: >> - >> - buf[0] =3D MSB(reg); >> - buf[1] =3D LSB(reg); >> - memcpy(buf + 2, data, len); > > I'm curious why a copy was made at all. > > Reviewed-by: Justin Stitt I guess the idea was to allow writing arbitrarily long contents to a single register with a single decriptor. The current version of the driver only ever writes a single byte value, but maybe it either used to have other writes, or it was meant to support them later but never did. Arnd