From nobody Tue Sep 29 14:54:46 2026 Received: from mail-pg1-f182.google.com (mail-pg1-f182.google.com [209.85.215.182]) (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 44A7243F0B6 for ; Fri, 7 Aug 2026 06:04:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786082641; cv=none; b=QqSloWxDQ5rvCdyLTvIFL78Z4pH9lPGydFjEeK1acC+w5X3VEeH3p8AqrDbmK9A1RzDowDJkKXW7aztoQKcw12G0ro2dgR9EmiopbbrmBVHsxXI00bOdBwo1UclCz5vQYkd2m1wYdo7bEdrinPSOiY867nw0DjH6nlzqCRcdVRw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786082641; c=relaxed/simple; bh=8VqW8kvm6CDSv32ZJLRDHAY1XXBUAN1d4rtNyqZ213Q=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=H8PtIrrMTBWKQsEkjrz+Kmino5CKsel7b5ZKDPjtx6OfCgoWDRsQP5Q7qoidC6Qy5aj1+FKZU8RNt1NzVDUaV3qedWwsmk2eacplbpTLh0Nus2UZIhNxmrY6ddwP7OiNuVXNDTzyl0vzE8PhbtXGHbQE5QTKKMQ2AxnqIcPXBc8= 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=ci4q+NY5; arc=none smtp.client-ip=209.85.215.182 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="ci4q+NY5" Received: by mail-pg1-f182.google.com with SMTP id 41be03b00d2f7-ca80d708489so1239357a12.1 for ; Thu, 06 Aug 2026 23:03:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1786082639; x=1786687439; 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=Bi/ZTEuo08hf/a8t6fkw1rlM/UqizQDgz+QeGcjEPh0=; b=ci4q+NY5X9IteROG4EyGRrouCWQYb4ATyd/iVms7qKMCmoK1euwuOAOTRY867Ygt1e 8F83rivmgCmNYQrLpYmGeYMU5+Xs8/pQnTHEQtfLq5xkvgQkol0S6El63L9TWQXh9kku jUj4f18hS0XG+knHsDgJ14cTbjAojRcIDogat4jhDEJa/qdiLED0/Wj6hEytH24/KiOt l9Q5bflxFZ1ygOsfN6T8z4OzOg4ybMdoR31idU7RX1u/bqkZO+Gy83jD7z0w3j1Xk54x Lh0xMh+Ha8yCJZcixa5SmE3QxjonCiTwP/QMCFdiZb8ClWkSo0YXOVn3Z3lAi3ptE6BE AAeg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1786082639; x=1786687439; 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=Bi/ZTEuo08hf/a8t6fkw1rlM/UqizQDgz+QeGcjEPh0=; b=LKG2kZMdw9T0gfxduIRimjH6qpmsvF6ZGOSFq6j/HCLuxVeoiiDXB7pPulDfvyLaV/ EUnmlCfBmAnzaHWXx15XGjH4gml6/+h1v+KYLmI1tWLh/sSykeB33MKLWQUVrD8d5qXS wxiOFnTE3k2ioSbHk/rTOcusGzzY6PjIJ4LkQHQG5yyPADZQMXwHnXgRJPOpgcBLUDkK x8j1j9wWuQz7lFRBM5JuaDHIh7c0LEeRqMrNzcYhIv0bBn3IiturNptWt1RivWF+jurR hL4a2N6KPTj93+iuD4PkRR/9pHiFP9VJR+KlxHjwCEl/8xYUFHNYEazR8gZnXGiqX4Fn Dpfw== X-Forwarded-Encrypted: i=1; AHgh+RqhzYLq1C61CnnHFKmN6P562JPnzE/EL8ZfMd3TF+e0BH2zaBr926rM+axcy4PIxMP/N5d2yXwN4Lfqz5U=@vger.kernel.org X-Gm-Message-State: AOJu0YzOu7x1xGlH+padYosX12/u0RvrZIq2AFbPBiCeWc88hqtr7zdT w1W2XdGtcxuBORQUq7LChLq8wE8kifOQCbu9I0noyxr0naJgZU6pfx7W X-Gm-Gg: AR+sD12/iynIinsQnRq8lz8Z0Iyu4LVEsI3uCyBveVxxUpxF3+DUxSUcIgaNVXGXAlH nQGhiW25d3BZxO7MtkopxTKvtXuVgipQniCRkHRdGc0rQz/F0l9rXlg3haoDtoVwhxQgjdICaCr jGw/9aQpyDcXVBTRd9FcORJCisj9s+CQolPfpb5EqwQRmPvKaJ1QxW6QJueJ+NMdeB5iC78SYvO yC+AeuF7/AAgmq402BwYMqUcD0nze+AjSNQS6YxZM/erD7DfONXWodFNgS4qYTtFara2wLiRev4 dDnBA9GY2XDdMkJgZqhfuth3y3kTiJ9ZYOit25q4rBo+V43NfK+H9LexnxkYyDhXB2Rpa4nYQv5 KQEzmViByCRPF7IdLOipjjhN4wd7kagebiDVZadSXWOZ+HcAOiJTmbt4MM0fuvWV6ntIeQQuec6 ZfydmLIiugYVZ3QWE+Pm5BUQI6p9b6sV4xWCNtMBbb1uilvQt04EzpM3r+FB/t/alyGbrcKFmAo hsEyw== X-Received: by 2002:a05:6a20:12c7:b0:3c3:75c5:48d5 with SMTP id adf61e73a8af0-3cb9c071bfdmr12830008637.4.1786082639405; Thu, 06 Aug 2026 23:03:59 -0700 (PDT) Received: from kernel ([45.251.35.98]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-141019b4244sm3635471c88.4.2026.08.06.23.03.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Aug 2026 23:03:58 -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 v3] staging: iio: frequency: ad9832/ad9834: add comment explaining do_div usage Date: Fri, 7 Aug 2026 11:33:48 +0530 Message-ID: <20260807060348.6477-1-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 --- 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..85f39ceb3c4c 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 fir within 32 bits, so do_div() is + * safe to use here + */ do_div(freqreg, mclk); return freqreg; } --=20 2.53.0