From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793099924; b=PvgaACwl9sNX5SNDtVta8fISJcp6vZStZ773uDbJ1GMNPasSccVAF3yi9YiuOKHutn/d 5tikjdWJY7NSBX9dK3ucmBbK8cLqvccb2VapJKegBrElj3u4C3peIgviGIfq+uUEj1EEj 0nWAfjnctAjV5HehrLlcF0NUTAjsDVRiozvFWhDUSEwwI8qKBxujhju0LMpk+4k/V8o6s RgK9qLv6gmtS4OWa6bVxolAndA/qj1AVuzPhJDZcrMKrS8DldZ2vHyWTIJD1UWzB08gWV o5qZAwbS5JD/S2XOxKFaPGH+fIPvVdp3MSByJfkOU284pM43IvirDWaiDVVjyVZy4fQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793099924; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=yEjEqaYwrK2Ud9tJD1KolehApwvEqJOUpjgkmRBg0QM=; b=DWxgfpUe2aKENvjdLsecbjJKIT7KjXHlMVtVXjudmpOMm7ZQoLmBHSELmb+yhNafzs83 StEGMSLP/YyVvLAUA71ln6jCAHbvTeZffY8Ift/mQLOI4U/Qu529PAwZld4ChjYMz6sGn omL9fUF/sNhOEVRj0Eem0clSMvrAxRjFZEn7/jxialBcMEgYMePoehqnVF4cBtd1FTJ6A o+4Q67VNn2kTRyaaMDu1PqXROipuZ/doReDpoX/9uJ3cTYt/mpNuGOUp/vB2K/Vormv6F 8vcErrkodWUEFki2lJW2CP2xPSotcfqsoqPB4e1795ZSUp2rK6uRqotJTwkNdIz2Rpw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fm0TS6Fq; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 93238606A31A for ; Tue, 27 Oct 2026 11:18:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fm0TS6Fq Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02F181F031E1; Tue, 27 Oct 2026 11:18:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793099924; bh=yEjEqaYwrK2Ud9tJD1KolehApwvEqJOUpjgkmRBg0QM=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=fm0TS6FqZRG0N4FeBmkCZcYnadKb7m2wC+F718N62cRMs5iGb6G7UoAn3jDMza9Rt JtabSrHkg+qtqr4VqSxeCLD1j3azTeYPKzX9//Dgf0nghx8HVs1TQqw/MrnL6HMeCR 0O4a3yieWcf7eQiHH032vBUtcBktDKSseMjLbRvOfN1vT8A05hf81HYAncWCnnnQnH n7oHAKkfLdLlck8zneK5pikZ4c0MpTXmfKJNvLxRCKBiJ4Ltv7x4hzewMkEgF4FMTx 3Xxv4o+uTCD0xB3h0zcES2WBqKdx4lXV/Nn++lymM5lMGdx9otgf/VrOeUd03Oorw5 LFK8IyW1qKc0A== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 16/24] serial: 8250_lpss: don't divide by 0 above 6.25 Mbaud Reply-To: sashiko-reviews@lists.linux.dev To: "Greg Kroah-Hartman" Cc: linux-serial@vger.kernel.org In-Reply-To: <20261027-tty-llm-v1-16-99b0202ae546@linuxfoundation.org> References: <20261027-tty-llm-v1-0-99b0202ae546@linuxfoundation.org> <20261027-tty-llm-v1-16-99b0202ae546@linuxfoundation.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 27 Oct 2026 11:18:43 +0000 X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Josef Bacik >=20 > byt_set_termios() derives the clock of the UART from the baud rate in > the termios, which nobody has looked at yet: >=20 > fuart =3D baud * 16; > ... > fuart *=3D rounddown_pow_of_two(fref / fuart); > ... > p->uartclk =3D fuart; >=20 > fref is 100 MHz. For a baud rate above 6250000, which BOTHER allows, > fref / fuart is 0, and rounddown_pow_of_two(0) shifts 1UL by -1. On x86 > that is 1UL << 63, the product with a multiple of 16 is 0, and so is > uartclk. serial8250_get_baud_rate() then passes 0 for both limits, > [ ... ] > Cc: Jiri Slaby > Cc: Heikki Krogerus > Cc: Peter Hurley > Signed-off-by: Josef Bacik > Signed-off-by: Greg Kroah-Hartman Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261027-tty-llm-v1= -0-99b0202ae546@linuxfoundation.org?part=3D16