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R. Silva" , sashiko-bot@kernel.org Subject: Re: [PATCH v8 1/8] iio: dac: ad5696: properly check i2c_transfer() return value Message-ID: <20260719002355.4a818026@jic23-huawei> In-Reply-To: <20260716-ad5686-new-features-v8-1-ebb0051af5e5@analog.com> References: <20260716-ad5686-new-features-v8-0-ebb0051af5e5@analog.com> <20260716-ad5686-new-features-v8-1-ebb0051af5e5@analog.com> X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Proofpoint-GUID: uMAPpD25P47nj49cBXEa8D7rFI30uqxC X-Proofpoint-Spam-Info: AW1haW4tMjYwNzE4MDI0OCBTYWx0ZWRfX/6J8x5VNYO8N QlQj3mN2nKete2dJTsOoiA9Xx5383VzAj1a3yxxymouFKUqB7bZcqsyX1qg3ZkxF8teX3UCF831 XSggA7pOt2ZaaEEF/bUDsAbn05qscwU= X-Authority-Analysis: v=2.4 cv=b9aCJNGx c=1 sm=1 tr=0 ts=6a5c0ef5 cx=c_pps a=cmESyDAEBpBGqyK7t0alAg==:117 a=qC1CW/w66vtJz1P9yTJxNA==:17 a=kj9zAlcOel0A:10 a=RAioF0-LDSMA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=eoimf2acIAo5FJnRuUoq:22 a=VwQbUJbxAAAA:8 a=gAnH3GRIAAAA:8 a=IpJZQVW2AAAA:8 a=eCasKaYD3dZQZqGzH0wA:9 a=CjuIK1q_8ugA:10 a=1OuFwYUASf3TG4hYMiVC:22 a=IawgGOuG5U0WyFbmm1f5:22 X-Proofpoint-ORIG-GUID: uMAPpD25P47nj49cBXEa8D7rFI30uqxC X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzE4MDI0OCBTYWx0ZWRfX1t6S3R+8QLTQ RH5cKwMnkeFG7O6PxSPQnjWQn9jKk+xvEBpdwep6GbfenLfGIQMI6QxryAaFStgguJbCyFYy+rm TQ5ZgpLEn9yparBLZmxfPLwGdLJ5BSnjxkRYD/DNKYfl2ovPXVG8oLM1M8+B6hA4LoMMdlrqyuy d8WhH08VxkxV6zYWsBqdeQv+k/hgnsNj7lUj6lD1jS3bdx6sB0SikFEqaNL3G0QQokDecT5HvzU qZNJf8vJ1hgGlbLPXHsHCZRR2krchE4myRqZOLPS9T5U7ng7gBA3akCUbhfdFeiYphBw/kiaDmL 3EnMggHP9aQqQRVanXVY0MAMyg07vX1FI4R5PtuUauUXmZfuTUSJP3gvEoKV7+07B9oUYZZ4TPD fKzu2Pv/qSVJgxfEQZuCTNwzwyuk8VBkrvDrtUdybdQff6vCett3w44eudk+x6Ax/aX+/7ey7Kr LyND57x16wPGHLeMCow== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-07-18_07,2026-07-17_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 suspectscore=0 phishscore=0 priorityscore=1501 lowpriorityscore=0 clxscore=1015 adultscore=0 malwarescore=0 bulkscore=0 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607180248 On Thu, 16 Jul 2026 13:14:17 +0100 Rodrigo Alencar via B4 Relay wrote: > From: Rodrigo Alencar > > Verify that the expected number of i2c messages were transferred when > ad5686_i2c_read() is called. This issue exists since the support for I2C > devices was first introduced. > > Fixes: 4177381b4401 ("iio:dac:ad5686: Add AD5671R/75R/94/94R/95R/96/96R support") > Reported-by: sashiko-bot@kernel.org > Closes: https://lore.kernel.org/all/20260705114746.1485F1F000E9@smtp.kernel.org/ > Reviewed-by: David Lechner > Signed-off-by: Rodrigo Alencar Let's hold off on this for now. Whilst it is technically correct today I'm looking into ensuring that we never need this. The only error case today is actually returning 0 which in practice is an error. > --- > drivers/iio/dac/ad5696-i2c.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/iio/dac/ad5696-i2c.c b/drivers/iio/dac/ad5696-i2c.c > index 279309329b64..551b200bfe14 100644 > --- a/drivers/iio/dac/ad5696-i2c.c > +++ b/drivers/iio/dac/ad5696-i2c.c > @@ -7,6 +7,7 @@ > * Copyright 2018 Analog Devices Inc. > */ > > +#include > #include > #include > #include > @@ -39,9 +40,11 @@ static int ad5686_i2c_read(struct ad5686_state *st, u8 addr) > AD5686_ADDR(addr) | > 0x00); > > - ret = i2c_transfer(i2c->adapter, msg, 2); > + ret = i2c_transfer(i2c->adapter, msg, ARRAY_SIZE(msg)); > if (ret < 0) > return ret; > + if (ret != ARRAY_SIZE(msg)) > + return -EIO; > > return be16_to_cpu(st->data[0].d16); > } >