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=1792880028; b=1JQwyEbDQpFf/zjMcZELlbNnVPMAAv7lr12pelhpoAYXYRzdvPf/Q0Ci/g0HgeckzCul 7mXkZPQEcLATpO/P4sKfNJJofNBHWEeMCqnBmW8hLKJdGskm2wgZAiz/HwkXpeY6+80gZ pzH9uqzy8Ohti/XX2BI+N1RZhUyj1b588fZxs/cUjI3fp9shHqP3M534zhaRIsi6oJ1F6 aBfoHkwcFPy3ywSsW0B2muiHG54gyMMmUkiSHELbIeRXKBeUedy22t7ROw6+KnXjVYkc9 SDFcW1W38SX56qhBQcax2gjfYJZ4pi5dKonJDaw9ZoQ23EX15gf8URMHbCDw/Djf0YQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792880028; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=+4MBVaVzNt0GZVO6eQK469IjMSEa21LCxzv3kU74efY=; b=jJ/5PTDAWsLIZvhyK4ibrwK/NgULzrCE645Ex+N2cdLUVLTotIfuUil8oM7FW/+FFfSN gNjvTTH5vj8h/Nlhu2SzDJr76gle3HfdVbJDHBC2d8AONU032pHHnpwDA8Eqsdm84NL4j lXgnWEzuClxchcrK5zHe++KhLKFhiv6uAU+vc9GaB9LnI4GFa7x+OUOpQZVV6fBRU06GK PJHLf5vKJO0GDlAxT2ulpL9mP+oWGmNCGjJEfCcKpk6HrtOmq8KQEihjOLiXgtAR/u/sr w9OOEcMUj4Ys8QlPwUhmpyukqDeO6QadI0s2IR10LU91ua4QmTHHBDPysn+8Oa1yREQ== 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="hokd/BfW"; 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 CFC91606A31A for ; Sat, 24 Oct 2026 22:13:47 +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=hokd/BfW Received: by smtp.kernel.org (Postfix) with ESMTPSA id 46CC31F01825; Sat, 24 Oct 2026 22:13:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792880027; bh=+4MBVaVzNt0GZVO6eQK469IjMSEa21LCxzv3kU74efY=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=hokd/BfWVEx6O816NPqqUCV1xfWTsU02wjhSrvgsQjW8DDeWvbwp1NotSEDdtsqL/ cNiswR+zJvmXEtpmET/VANAyFEe4dNA0i9bayqDr5wGTLZZwJQQYeXcmItMECi6xNA j4Dd4bf8xA2BqgWIXnVpM/v58ko4x6xtjUqRzokSEoC8yM8hFgbpfhBu4s1nlhHgEb B51+JEHpMcmzv/GLX9mckyk3se+EyGFGShZZUpl3CZxkeykdFhhHBF4DWjKVF+LMEi Ga1w6qtYEuDWRMaSo+TRqbZ4H53Czec9oWZDduPrO2t62ZTruWRx2CPdOe9ZxKQXR+ T0+7IAd+W7vrw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 2/2] serial: 8250_ingenic: Set UMR and UACR at probe Reply-To: sashiko-reviews@lists.linux.dev To: "Olivier Louvignes" Cc: linux-serial@vger.kernel.org In-Reply-To: <20261024220712.23250-3-olivier@mgcrea.io> References: <20261024220712.23250-1-olivier@mgcrea.io> <20261024220712.23250-3-olivier@mgcrea.io> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 24 Oct 2026 22:13:46 +0000 X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > Ingenic UARTs have two registers beyond the 16550's: UMR, the number of > clocks a bit takes, and UACR, which adds one clock to chosen bits of a > frame, for fractional baud rates. The JZ4725, JZ4740, JZ4755, JZ4760, > X1000, X1830, X2000 and X1600 programming manuals all have them at 0x24 > and 0x28. The divisor the 8250 core computes assumes 16 clocks a bit and > none added. >=20 > The driver never writes them, so a UART keeps whatever was there before. > On a HiBy R1 (X1600) the vendor boot loader sets UMR to 8 on its console > UART, and the vendor kernel had left 8 on UART0, which carries the > Bluetooth chip: every rate came out doubled, and the chip never answered > ("command 0xfc18 tx timeout" from hci_bcm). Their reset value, 0, which > the X1000 and X1600 manuals call normal mode, does not work on the X1600 > either: with UMR at 0 the same command times out. >=20 > Set UMR to 16 and UACR to 0 at probe. >=20 > Tested on a HiBy R1: with UMR at 0 or 8 the BCM43430A1 on UART0 fails to > set up; with this patch it comes up at 1.5 Mbaud and streams A2DP audio. >=20 > Signed-off-by: Olivier Louvignes Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261024220712.2325= 0-1-olivier@mgcrea.io?part=3D2