From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1A488C761A6 for ; Tue, 4 Apr 2023 12:37:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=P3kn/8S1xc/HKZiqOskmQI/IGeT4LxOu4yrDjTS/9m0=; b=IIyg9LE0Sq8aVi S/C19qPoRvhRShzrj6tQT/692TgNAktqhMB4K/cIU0NmODymZ72XohaSEaA+Wtiy96DCiadq5/hyX flWd7U5/4bKXWlt4FYoD8yhZ/kt90H9WOcdHNbSZZ2U4GCb+w4R1S1NLStkWi+aUwiBTxroMV1U2Z UzFeIZZ2cRCJRYYond0qURZ3LebhMZI1neWNBXc4mN8hL2jirDog2MY2d6suKM4qfYNJY6MrcDTTu FMiqHLqQ/L3XvVWUXNAxz18fL3aFW5IQC/47UtwtoJ7J4DQmlScLNsj+LXf1Z7z4uPx0xIuaAmsJ7 hqMNZrNwUOgew8FZvhZQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pjfu8-001ITl-2B; Tue, 04 Apr 2023 12:36:52 +0000 Received: from vps.xff.cz ([195.181.215.36]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pjfu5-001ISY-0j; Tue, 04 Apr 2023 12:36:51 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=xff.cz; s=mail; t=1680611806; bh=5FjolS6OmiyNi3Dzbu2WcgmbPn9JvTWmxSdnDWKiKWQ=; h=Date:From:To:Cc:Subject:X-My-GPG-KeyId:References:From; b=ekYLNbm4eIMpAS/2QpV2eXW1eLcINLpi0sYHFXrqmJpHL9JDeStckypjFhusNmFjO dNaOyaUhPx5+HAEjMbueIreyWQd0chPLZtqnu2+pn0143cXUOJBiqKUo4HiG72zq1L +VS4wNkcANEH1vpPfgM82qM9M91Qb1ThqqEn5oYI= Date: Tue, 4 Apr 2023 14:36:46 +0200 From: =?utf-8?Q?Ond=C5=99ej?= Jirman To: Heiko =?utf-8?Q?St=C3=BCbner?= Cc: linux-kernel@vger.kernel.org, Javier Martinez Canillas , Peter Robinson , Caleb Connolly , Jarrah Gosbell , Krzysztof Kozlowski , Martijn Braam , Rob Herring , Tom Fitzhenry , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org Subject: Re: [PATCH] arm64: dts: rockchip: Change serial baud rate for Pinephone Pro to 1.5 MB Message-ID: <20230404123646.5iiznbhnyoama5pp@core> Mail-Followup-To: =?utf-8?Q?Ond=C5=99ej?= Jirman , Heiko =?utf-8?Q?St=C3=BCbner?= , linux-kernel@vger.kernel.org, Javier Martinez Canillas , Peter Robinson , Caleb Connolly , Jarrah Gosbell , Krzysztof Kozlowski , Martijn Braam , Rob Herring , Tom Fitzhenry , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org X-My-GPG-KeyId: EBFBDDE11FB918D44D1F56C1F9F0A873BE9777ED References: <20230403175937.2842085-1-javierm@redhat.com> <3738011.44csPzL39Z@diego> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <3738011.44csPzL39Z@diego> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230404_053649_716068_DBA9424A X-CRM114-Status: GOOD ( 32.36 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Apr 04, 2023 at 09:51:11AM +0200, Heiko St=FCbner wrote: > Hi, > = > Am Montag, 3. April 2023, 19:59:37 CEST schrieb Javier Martinez Canillas: > > This baud rate is set for the device by mainline u-boot and is also what > > is set in the Pinebook Pro Device Tree, which is a device similar to the > > PinePhone Pro but with a different form factor. > > = > > Otherwise, the baud rate of the firmware and Linux don't match by defau= lt > > and a 'console=3DttyS2,1500000n8' kernel command line parameter is requ= ired > > to have proper output for both. > = > The interesting question is always if this will break someone else's setu= p. > I've never really understood the strange setting of 1.5MBps, but on the > other hand it _is_ a reality on most boards. Normal users of the phone probably run with UART console disabled, because UART is muxed with audio jack output and to enable it they have to add console=3DttyS2 to the kernel command line and flip a physical switch inside the phone. Fortunately, not sepcifying stdout-path baud rate in the options part of the string, will make the serial driver probe for the baud rate from the previous boot stage and make the user happy by keeping whatever was already set in the bootloader. https://elixir.bootlin.com/linux/latest/source/drivers/tty/serial/8250/82= 50_port.c#L3496 So we can make the kernel just keep the baudrate setup from the previous boot stage by: stdout-path =3D "serial2"; regards, o. > Personally I don't care that much either way, but would like a comment > from the other people working on that device - if possible. > = > I guess if we don't hear anything, I'll apply it nevertheless at some poi= nt > = > = > Heiko > = > = > > Signed-off-by: Javier Martinez Canillas > > --- > > = > > I tried to instead get rid of the baud rate altogether, as suggested by > > Peter Robinson. AFAIU that should just pick whatever bad rate has been > > using by the early console. > > = > > But neither using 'stdout-path =3D "serial2" nor 'stdout-path =3D &uart= 2' > > worked for me. > > = > > In both cases I didn't have any output unless setting a baud rate using > > the 'console=3D'param. > > = > > arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > = > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts b/ar= ch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts > > index a0795a2b1cb1..6bbe65bd5bd4 100644 > > --- a/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts > > +++ b/arch/arm64/boot/dts/rockchip/rk3399-pinephone-pro.dts > > @@ -26,7 +26,7 @@ aliases { > > }; > > = > > chosen { > > - stdout-path =3D "serial2:115200n8"; > > + stdout-path =3D "serial2:1500000n8"; > > }; > > = > > gpio-keys { > > = > > base-commit: 3adf89324a2b2a9dbc2c12d8895021e7e34e3346 > > = > = > = > = > = _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel