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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: devicetree@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-Spam-Info: AW1haW4tMjYwNzE4MDI0OCBTYWx0ZWRfX7wtEpIe8Xcta uJU8xQGoh2JAL9Pwj9XqBXswQdmOTWUfc/cDgqWxaW2fJgowfYHa2EeybXcBhtI7vx8o9m6EpnS gUNXPGp4vfSVKC/rKU3jHjcvKGdtMh8= X-Proofpoint-GUID: tyD3mY_rmOfSCKLxgUf2QkMMKNJi6ICO X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzE4MDI0OCBTYWx0ZWRfX9YN3dUdO8KgG 740x7wRo4qB3Dm1wRE2wb6CT3DboMm1iJUrgFYOyQESpjQ8YdXaZb2cpACyqtI+GEiZTKlo0mWT 1fkH6sc4I/MHARZexYsJYwiEX6989TXPixmAZ4X/ncQQKeOqa2LxfYIeplMPMm9wh+3c35Z5V6t p149WaRJK6MHhueUmW+pQMUymtezGHkT7EcuC2DXCfuLG5oaEq1UL9nkcoI+1DH37FAaudebLa2 20CYBMZg4tJ925uIjZ/Hq8F7w15axRs1PQE55uK+LT0wBF4dM5tzJJiVPY9kv4cAxaam3v1Rhwr ywK7hP80KgOLLiA9JbO9CyDSS44VKobF0zF7+OMyn/LHUd/BQqOuwJ3s2Pd1uERfzmR39Td0wjI 8+N8LKRi+D9mS/kTyiwcSm7EgDMlnA+I2rzIu/WtSagv6qiibA2Nb0rB7VvBUrZzpzLPycrdwGu aKAXRWMhyfVvULOpDWw== X-Authority-Analysis: v=2.4 cv=T5K8ifKQ 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=yx91gb_oNiZeI1HMLzn7:22 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-ORIG-GUID: tyD3mY_rmOfSCKLxgUf2QkMMKNJi6ICO 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 phishscore=0 malwarescore=0 impostorscore=0 bulkscore=0 adultscore=0 suspectscore=0 lowpriorityscore=0 spamscore=0 clxscore=1015 priorityscore=1501 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); > } >