From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from elvis.franken.de (elvis.franken.de [193.175.24.41]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 8BDD933263B; Mon, 6 Apr 2026 12:35:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.175.24.41 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775478912; cv=none; b=I3pwjebWf6f//AL9mwO+RPBVKVeVaXb5EvFJuxm3oArrg0oIThoNjgTig8vKD7CJ/VRvK8htfBITVV/xy7EKdaxlHQmoY9uVoBjykSjDVj3FDSUvTRd80dh7A8DiEMga6qwlqPXzhcDv037wZMab1bN3bCMu6bvQSU37/qtNX94= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775478912; c=relaxed/simple; bh=vo/6lo+iAkG6UawG71EzFRxbyPgiOp0wfB7hhPyA8g0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NhHSijcH3z2UuyqCTdmJN+KRcCFnayNJNQzWOsKeR2PRlRKsKxIE679o1rE+sVTsymCo+V4C8DqBzxe4I7AfExMQmMqKFMOA3rwLPzZJsWG06YXEaNlQRgiaADePGWczF825gOeIk1ZRujuSbKBEG/54EZ8MfF+Kco5h3Cuz0qo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=alpha.franken.de; spf=pass smtp.mailfrom=alpha.franken.de; arc=none smtp.client-ip=193.175.24.41 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=alpha.franken.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=alpha.franken.de Received: from uucp by elvis.franken.de with local-rmail (Exim 3.36 #1) id 1w9jAQ-00040t-00; Mon, 06 Apr 2026 14:34:58 +0200 Received: by alpha.franken.de (Postfix, from userid 1000) id 6973EC0DC9; Mon, 6 Apr 2026 14:32:19 +0200 (CEST) Date: Mon, 6 Apr 2026 14:32:19 +0200 From: Thomas Bogendoerfer To: Rong Zhang Cc: Greg Kroah-Hartman , Jiri Slaby , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Huacai Chen , Jiaxun Yang , linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, linux-mips@vger.kernel.org, devicetree@vger.kernel.org, Yao Zi , Icenowy Zheng , Rong Zhang Subject: Re: [PATCH v2] MIPS: dts: loongson64g-package: Switch to Loongson UART driver Message-ID: References: <20260315184401.413975-1-rongrong@oss.cipunited.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260315184401.413975-1-rongrong@oss.cipunited.com> On Mon, Mar 16, 2026 at 02:44:00AM +0800, Rong Zhang wrote: > Loongson64g is Loongson 3A4000, whose UART controller is compatible with > Loongson 2K1500, which is NS16550A-compatible with an additional > fractional frequency divisor register. > > Update the compatible strings to reflect this, so that 3A4000 can > benefit from the fractional frequency divisor provided by loongson-uart. > This is required on some devices, otherwise their UART can't work at > some high baud rates, e.g., 115200. > > Tested on Loongson-LS3A4000-7A1000-NUC-SE with a 25MHz UART clock. > Without fractional frequency divisor, the actual baud rate was 111607 > (25MHz / 16 / 14, measured value: 111545) and some USB-to-UART > converters couldn't work with it at all. With fractional frequency > divisor, the measured baud rate becomes 115207, which is quite accurate. > > Signed-off-by: Rong Zhang > --- > This patch targets the MIPS tree. > > The series for the serial tree to update dt-bindings and enable building > 8250_loongson (loongson-uart) on MIPS Loongson64 is sent separately, as > it's independant of this patch and can be applied in any order (the > compatible strings here still contain "ns16550a", so no regression will > be introduced). > > Changes in v2: > - Separated from v1 (patch 3): https://lore.kernel.org/r/20260314234143.651298-1-rongrong@oss.cipunited.com/ > (thanks Krzysztof Kozlowski) > --- > arch/mips/boot/dts/loongson/loongson64g-package.dtsi | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) applied to mips-next Thomas. -- Crap can work. Given enough thrust pigs will fly, but it's not necessarily a good idea. [ RFC1925, 2.3 ]