From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4478B18D635; Tue, 6 Aug 2024 16:19:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722961174; cv=none; b=SxauEAwGRuuxn980NrTTLbw91k7kvx5y7Suz/+t1BJk9K792C8Uxm18OyuosOXutZ3cD36iOCn3iYaNFmeJT0Q6f6gKj0EFWSZdlqe5/Xp0TjS7GBX1yx2YPSFZoN1usyAC9WZt3WN4llycLycCHltU89kCfbzjd5WL4QsnuzM4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722961174; c=relaxed/simple; bh=YeNtWL8whpfWe7Qhmm7tHCJLQzbTIh7pEh655CaEFFc=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=t+txbm3g5AYhT5oGRcFjk6e0Cgz12l7K7Wf+TrrKx1o7QLIgf8GFwAw4xP/+vluRXt0lWVi8+GEFqXfkjB9ygGl6t9SMnAUkd9ldY52VAtB8PdfScaJ+cvpfFdnQYN83HV6gDvWYbJTK6vm5P3xabdc5KRZPegw14fpyjrBuZKk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MNOtgoiX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="MNOtgoiX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 023CDC32786; Tue, 6 Aug 2024 16:19:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722961173; bh=YeNtWL8whpfWe7Qhmm7tHCJLQzbTIh7pEh655CaEFFc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=MNOtgoiXpqhi2l5U0hIfOOGOMtr3BCH/EYqpGxvsw0J7FroWVXiwp612R5h38NtvU 0/MZk25DK+ZpC9BfU7PjObNECuLOCz5ztnCNAbElxac5znoLkA9JY8xYQhZDpzQFEY mXR6Lk8c53nHymIO4QJ/FjEscPnPzMimE+3A8axjXXcLhuYrdEQ2/naPsnw5H9zOLW dCy6DiHc8j0XJIk61Vyqa0SRyPNUKgHJWOwAH1ePJxJhJjH7RtbAK8rkPntvRwNz4k Va+OT4Uoir/xwaHnPCmu4kmL3cjYkBd88b7GbondYR9xRmUUF3q+/49VLDqtmH+Cni vRZYopRvLPaFw== Date: Tue, 6 Aug 2024 17:19:25 +0100 From: Jonathan Cameron To: =?UTF-8?B?QmFybmFiw6FzIEN6w6ltw6Fu?= Cc: Lars-Peter Clausen , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Albrieux , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux@mainlining.org Subject: Re: [PATCH v2 1/3] iio: magnetometer: ak8975: Fix reading for ak099xx sensors Message-ID: <20240806171925.7c512c63@jic23-huawei> In-Reply-To: <20240806-ak09918-v2-1-c300da66c198@mainlining.org> References: <20240806-ak09918-v2-0-c300da66c198@mainlining.org> <20240806-ak09918-v2-1-c300da66c198@mainlining.org> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; 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=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, 06 Aug 2024 08:10:18 +0200 Barnab=C3=A1s Cz=C3=A9m=C3=A1n wrote: Hi Barnab=C3=A1s, Welcome to IIO. > ST2 register read should be placed after read measurment data, > because it will get correct values after it. What is the user visible result of this? Do we detect errors when none are there? Do we have a datasheet reference for the status being update on the read command, not after the trigger? > Needs a Fixes tag to let us know how far to backport the fix. A few comments inline. =20 > Signed-off-by: Barnab=C3=A1s Cz=C3=A9m=C3=A1n > --- > drivers/iio/magnetometer/ak8975.c | 31 +++++++++++++++---------------- > 1 file changed, 15 insertions(+), 16 deletions(-) >=20 > diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer= /ak8975.c > index dd466c5fa621..925d76062b3e 100644 > --- a/drivers/iio/magnetometer/ak8975.c > +++ b/drivers/iio/magnetometer/ak8975.c > @@ -692,22 +692,7 @@ static int ak8975_start_read_axis(struct ak8975_data= *data, > if (ret < 0) > return ret; > =20 > - /* This will be executed only for non-interrupt based waiting case */ > - if (ret & data->def->ctrl_masks[ST1_DRDY]) { > - ret =3D i2c_smbus_read_byte_data(client, > - data->def->ctrl_regs[ST2]); > - if (ret < 0) { > - dev_err(&client->dev, "Error in reading ST2\n"); > - return ret; > - } > - if (ret & (data->def->ctrl_masks[ST2_DERR] | > - data->def->ctrl_masks[ST2_HOFL])) { > - dev_err(&client->dev, "ST2 status error 0x%x\n", ret); > - return -EINVAL; > - } > - } > - This completely removes the check from the _fill_buffer() path > - return 0; > + return !(ret & data->def->ctrl_masks[ST1_DRDY]); returning a positive value here is unusual enough you should add a comment = for the function + use that return value. > } > =20 > /* Retrieve raw flux value for one of the x, y, or z axis. */ > @@ -731,6 +716,20 @@ static int ak8975_read_axis(struct iio_dev *indio_de= v, int index, int *val) > ret =3D i2c_smbus_read_i2c_block_data_or_emulated( > client, def->data_regs[index], > sizeof(rval), (u8*)&rval); No longer gated on ret & data->def->ctrl_masks[ST1_DRDY] which seems uninte= ntional. Still need a check on ret here. > + ret =3D i2c_smbus_read_byte_data(client, > + data->def->ctrl_regs[ST2]); > + if (ret < 0) { > + dev_err(&client->dev, "Error in reading ST2\n"); > + goto exit; > + } > + > + if (ret & (data->def->ctrl_masks[ST2_DERR] | > + data->def->ctrl_masks[ST2_HOFL])) { > + dev_err(&client->dev, "ST2 status error 0x%x\n", ret); > + ret =3D -EINVAL; > + goto exit; > + } > + > if (ret < 0) > goto exit; And this one ends up redundant I think which suggests to me the code is inserted a few lines early. > =20 >=20