From nobody Tue Sep 29 13:20:17 2026 Received: from mail-pg1-f174.google.com (mail-pg1-f174.google.com [209.85.215.174]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 955F52EEE9E for ; Fri, 7 Aug 2026 09:47:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.174 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786096036; cv=none; b=Ek9s+f23e8ujgC7rknXfQiGPRGB+18FBPJUPHC8lEwE120UgGxtZJTNE9VmV+nCVti8bUmdDjIBTIrA0OlAQteEJXSSnXNrHDoRGZA4SNE3PetIkdfHIIA64qdJivDT91x9Yoa7f9x1CVxcFK1KNWuKcG+IXs6TyAqVXvsSuehk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786096036; c=relaxed/simple; bh=HhxupGz1WHaq42O8GavvnZENK1sHfqrxEzKdKto82ec=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=L6Mc+M0nV+6VSYyxC5sUFuUqgCb/lIsyV/lCKSHhlIj+GbX+hEN4AkZFe7fIKQJPbpQ9mm2k60JbUwMQBM5LQ1RrSfboLeWWv5x6MxYYSwyFlXqQnqGAIneOZQ+VHeGUANY2q4j6b7l3zW92wYzUc4AIA/ERUok5/cLhRUqs8mM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=mJR6AAB/; arc=none smtp.client-ip=209.85.215.174 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="mJR6AAB/" Received: by mail-pg1-f174.google.com with SMTP id 41be03b00d2f7-c96b08cdd1cso2407695a12.0 for ; Fri, 07 Aug 2026 02:47:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1786096035; x=1786700835; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=7Ex4kLoFeCE7JpX1METI8NE7HW5gn3lcnhSZrjT8Evw=; b=mJR6AAB//Zpk8Mjgi5QgbG9G3nabPQnSTApkCgnjRzsNyK0Qcln/N7cyk5o3fkxidq krAzTwM/RrErQAoMdd8iyOxwxps0Y9o7SevOmjyp8WlARir1BYeMcqiGzG6JFkQcIasK voiiQNa+DadgC+EAPl1H5/BGK9M51zznee1+IuMhkycgj/8UXpueHT5DkO4fHhNLhIu/ auY8fgl7FXGMR6YKJoXBmUCbhUhhXfuQ5Dw9H5UqbC2R48IW7T+y+Zi2frgWbqm4hMZu u07eETD+WkpX4KL9rRaR9anaxU9DZClS2dNqXl53CSd/7c9XocGgw5NEFy9gv6soZlrl AFaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786096035; x=1786700835; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=7Ex4kLoFeCE7JpX1METI8NE7HW5gn3lcnhSZrjT8Evw=; b=sqiC/PIhSwYiYQsFkwT7MzLfziNQli1S+gzTQbaSxFsyBgj1OF4qeZGC1aRyA2VMJ9 fMvP2s7u0i6bIWwB/7rxk0gHYFRLIjs/g3Pn+bxjdPtbfN9J3ypmKyOxKBl5obKisyyl 6I73aXiWOcf48Ojb6N3HV7ekvUUkWmVsMkcgknOkh6lPJAVUqfGmRlbq/cHA3m1bfJtv p2fQXS8CQ5QO8yMxRiDWDqIIhoKiQ5XFYq+qAwgrfR2QDVv3c59ld5Czr/dX4BLKk/Zp 4McvIsXSomvcSwxpdhW/UvXZjDPTKaNltGSjisalzEW1fz2AIrIAzO1gHybE5pmDZ09m 8TtQ== X-Forwarded-Encrypted: i=1; AHgh+Ron9YJ7C5vWFl9VfJGJdDtkiEqpw0HWQO7/yMxfLVLI3ccvnk5p9rmHvPxPYUi7gy7fSPGPMtcSi6UCTFw=@vger.kernel.org X-Gm-Message-State: AOJu0Yyw3rkN1CIAajLXeBJnM6mf4ci8JlcIhTN/rNOlEN3fErYZMuFo sg7IRtq1IraN8i5AEzQY7GmZ6xjTmx6AasoxuKcS+WX9ALpQW+E9L6YL X-Gm-Gg: AR+sD122qz5VlfWW/R7EHjMmMlSgK1tOJ0BOJ0qKtN7rB8v+bungpOrApsrZ67l4Hju 4h/ebHFiDmWEt30nnsDy/CkKo7gcXbVbaxFJvcp2SWHEM4lsIyn8FORBCQcvB8SoHECLJRrL7DV jqxoB5AV/mFW1wd8BjhYRAKTBOXs2PZqluycszRswj/afU3OWRYOAHDVH++mnZYc6TpUoBHwxsj SoeijBZ+FQ98aXTOWhu+ci2LAywSBjQgLCD6rXkbx4NT5Lfna7K+n8izNQgMlf4NnHiimL7mQC0 0Zyqd/MB73cYbq66BZJv4MnfRP0zItzjrppoL3sRcbPYns0LOS38nLef6OT055AMese8fCEUfU7 SX9gM3qIQbLrpKXhAlYWbN4QDT5Dw/5SWc65PKOvU12z7F+NH5bEkQ8pmpe865UAWFfQ0o9iPZZ LxbEvfb1GjQHO0AokZAOc/BWj6+bOAk9Fa4ZSfsulXHs6Jqfn7e76KIaIuSZKtinvY94ZrA5+3c NZlKw== X-Received: by 2002:a05:6a21:3a86:b0:3c3:ad17:eded with SMTP id adf61e73a8af0-3cb8603af51mr25109132637.36.1786096034883; Fri, 07 Aug 2026 02:47:14 -0700 (PDT) Received: from kernel ([45.251.35.98]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-315bec5aac2sm5832048eec.30.2026.08.07.02.47.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Aug 2026 02:47:14 -0700 (PDT) From: Mohamad Raizudeen To: andriy.shevchenko@intel.com, jic23@kernel.org, dlechner@baylibre.com, andy@kernel.org, nuno.sa@analog.com Cc: gregkh@linuxfoundation.org, joshua.crofts1@gmail.com, skhan@linuxfoundation.org, me@brighamcampbell.com, jkoolstra@xs4all.nl, linux-iio@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, Mohamad Raizudeen Subject: [PATCH v4] staging: iio: frequency: ad9832/ad9834: add comment explaining do_div usage Date: Fri, 7 Aug 2026 15:17:03 +0530 Message-ID: <20260807094704.5371-1-raizudeen.kerneldev@gmail.com> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Previous attempts to change do_div() to div64_ul were rejected because mclk will always fit within 32 fits for this hardware, making do_div() safe to use. However, Coccinelle continues to flag this as a false positive. To prevent future developers from submitting unnecessary fixes, add a comment explaining why do_div() is intentionally kept. Suggested-by: Andy Shevchenko Signed-off-by: Mohamad Raizudeen Reviewed-by: Andy Shevchenko Reviewed-by: Joshua Crofts --- Changes in v4: - Fixed typo in comment (fir -> fit) as pointed out by Joshua Crofts. drivers/staging/iio/frequency/ad9832.c | 6 ++++++ drivers/staging/iio/frequency/ad9834.c | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/f= requency/ad9832.c index 60c33e10c46f..2e216c950c53 100644 --- a/drivers/staging/iio/frequency/ad9832.c +++ b/drivers/staging/iio/frequency/ad9832.c @@ -118,6 +118,12 @@ static unsigned long ad9832_calc_freqreg(unsigned long= mclk, unsigned long fout) { u64 freqreg =3D (u64)fout << AD9832_FREQ_BITS; =20 + /* + * mclk is an unsigned long, which triggers a Coccinelle false positive + * warning about using do_div() for 64-by-32 division. However, mclk + * for this hardware will always fit within 32 bits, so do_div() is + * safe to use here. + */ do_div(freqreg, mclk); return freqreg; } diff --git a/drivers/staging/iio/frequency/ad9834.c b/drivers/staging/iio/f= requency/ad9834.c index 33dfd723923c..e089a94db97d 100644 --- a/drivers/staging/iio/frequency/ad9834.c +++ b/drivers/staging/iio/frequency/ad9834.c @@ -103,6 +103,12 @@ static unsigned int ad9834_calc_freqreg(unsigned long = mclk, unsigned long fout) { unsigned long long freqreg =3D (u64)fout * (u64)BIT(AD9834_FREQ_BITS); =20 + /* + * mclk is an unsigned long, which triggers a Coccinelle false positive + * warning about using a do_div() for 64-by-32 division. However, mclk + * for this hardware will always fit within 32 bits, so do_div() is + * safe to use here. + */ do_div(freqreg, mclk); return freqreg; } --=20 2.53.0