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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-kernel@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: 1ZqSHqixhYkT3V6U4pwzpLDLV3tsHcsJ X-Proofpoint-ORIG-GUID: 1ZqSHqixhYkT3V6U4pwzpLDLV3tsHcsJ X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzE4MDI0OCBTYWx0ZWRfX2kIx9jGqvPAm 0lvKVrSlD9SJ0c84MrH/X0i1Zi404J7jYTymQm18zub0V2vwuXise+L7th5LTK9HArUUI1SpG38 CKZ1RaoSZA0jdJouuKl9spJ0aPxb8nyKYKcEQTc1eiQk4Ei8yWWk7dmzKSr0UX/58u1wMumc+Ou rzz8n867nL7jPAhHjQhCeHpkTvEi2exhj73/Y53jCQz6fmsG1cVjtBvp1U6iWYCtA6M6HF3MvMR w15bkY7+NcRvjJShEBpw6Go0Mv9VCaNCaINQXob+vl+Ig677BAzjxcKONPntykYdmzw62synMqm bjYN4+8oh8wCiWdV1Akzxq10LtL4zdS+pq31RRL769eIZcIS7J5b7XiFElJjSPTxHGr7eZsCunL ziG3TuahV+GMIo0RSp13mPVb//HqMpFkJIaeK4awkCA12evxjIBr841TnK9YtcErc3mIcENpqwf XguKgzOtdb+1RDHwglQ== X-Proofpoint-Spam-Info: AW1haW4tMjYwNzE4MDI0OCBTYWx0ZWRfX7blQ/Avlqzmv +4U2Zf91w6hoAITl+icfjn2GZqyA1kwDO5ZmYPFF3MYYK7H21y+7XmDl2nyE7dChchW//cY/JKF lQkI3b1dD/7rlr/63YdDG+tpGno9JtQ= X-Authority-Analysis: v=2.4 cv=YsQ/gYYX c=1 sm=1 tr=0 ts=6a5c0ef5 cx=c_pps a=JL+w9abYAAE89/QcEU+0QA==:117 a=qC1CW/w66vtJz1P9yTJxNA==:17 a=kj9zAlcOel0A:10 a=RAioF0-LDSMA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=rJkE3RaqiGZ5pbrm-msn:22 a=VwQbUJbxAAAA:8 a=gAnH3GRIAAAA:8 a=IpJZQVW2AAAA:8 a=eCasKaYD3dZQZqGzH0wA:9 a=CjuIK1q_8ugA:10 a=324X-CrmTo6CU4MGRt3R:22 a=IawgGOuG5U0WyFbmm1f5:22 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 priorityscore=1501 phishscore=0 adultscore=0 lowpriorityscore=0 suspectscore=0 clxscore=1015 spamscore=0 malwarescore=0 bulkscore=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); > } >