From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (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 CCE4E3A9872 for ; Wed, 12 Aug 2026 07:59:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786521595; cv=none; b=Q3YCztZZ8XK5a4XjQEXk3C/w358vmluyRmuVrxx5pMlskZaVMlu6nHsGQBmvtuPYfzO1YR97wnhht4EmxJaX2SJV2DOjFgsrJoamLuKQ7EErqymDC53IFQ8SqdgPwx7X8In4v++sPNn2mWAVGv6q5qzZm5qirIwP1XzjP9B+5rU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786521595; c=relaxed/simple; bh=IP65GVh5iliVMfpmakpvzbSYWId+HtkY3xuM6WIn/QI=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=s50KZju8e7bY49UXpzSn6ZADDFtHs4ox4nxFbfhvGCocEsIH5+slRN+5HG4vAwpqwBwUr6WA6QSf4XJgtX4CXKru9BgoJOb6jvxigHJFPXgwkymHv2aheUlTJtqTyxQvgOfLwIRT7N5FlikbsVldUk8Keg/sQKmhYuiZL32FR4c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=JU6uYaE3; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="JU6uYaE3" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1786521591; bh=IP65GVh5iliVMfpmakpvzbSYWId+HtkY3xuM6WIn/QI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=JU6uYaE3mdyV97MiTuv/yTRW2fPAVrv/qNDCEYpCGlVntxkwJk8KZX6AM2opJP+lX VEuyjPa5WI/qdLfA4aJFSVj83+5pc3XbceuA5+lUccN5kqC1kd3oG1/+sO4fwgDYyO czToL2ej/8K+OkQpu3w1vk0ntpm82OVb6Vbkn+GEOk/MLAbbyjqKs9ZzDijjsrMT1E 1HBwixdWeSqslKCTW5WBDCylLHSyfK64JWqdktodkA6n8tdbNff6zrC8lX0cfdVCoJ piloTnb5hGKJigPQmcgTA6IxPFCbe7OmoZs7Qm/DOk60grozhqSxCQgNFzXCKYivvA n5cTizevCP+dA== Received: from fedora-21.home (unknown [100.64.0.11]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange secp256r1 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id E555017E0E95; Wed, 12 Aug 2026 09:59:50 +0200 (CEST) Date: Wed, 12 Aug 2026 09:59:45 +0200 From: Boris Brezillon To: =?UTF-8?B?QWRyacOhbg==?= Larumbe Cc: Rob Herring , Steven Price , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Faith Ekstrand , "Marty E. Plummer" , Tomeu Vizoso , Eric Anholt , Alyssa Rosenzweig , Robin Murphy , Philipp Zabel , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Collabora Kernel Team , Neil Armstrong , Claude Subject: Re: [PATCH v5 02/11] drm/panfrost: Prevent division by 0 Message-ID: <20260812095945.62199da1@fedora-21.home> In-Reply-To: <20260811-claude-fixes-v5-2-3d692c9e98c2@collabora.com> References: <20260811-claude-fixes-v5-0-3d692c9e98c2@collabora.com> <20260811-claude-fixes-v5-2-3d692c9e98c2@collabora.com> Organization: Collabora X-Mailer: Claws Mail 4.4.0 (GTK 3.24.52; x86_64-redhat-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=UTF-8 Content-Transfer-Encoding: quoted-printable On Tue, 11 Aug 2026 22:42:11 +0100 Adri=C3=A1n Larumbe wrote: > When updating and debug-printing devfreq stats, in the very unlikely > off-chance that total device time is less than 100 ns, division by 0 > would happen. Fix the divisor when relevant and rearrange operands. >=20 > Reported-by: Claude > Closes: https://gitlab.freedesktop.org/panfrost/linux/-/work_items/88 > Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver") > Reviewed-by: Steven Price > Signed-off-by: Adri=C3=A1n Larumbe Reviewed-by: Boris Brezillon > --- > drivers/gpu/drm/panfrost/panfrost_devfreq.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 > diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/dr= m/panfrost/panfrost_devfreq.c > index b51c30778811..0fe81d259274 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c > +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c > @@ -78,7 +78,7 @@ static int panfrost_devfreq_get_dev_status(struct devic= e *dev, > =20 > dev_dbg(pfdev->base.dev, "busy %lu total %lu %lu %% freq %lu MHz\n", > status->busy_time, status->total_time, > - status->busy_time / (status->total_time / 100), > + status->busy_time * 100 / MAX(status->total_time, 1), > status->current_frequency / 1000 / 1000); > =20 > return 0; >=20