From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3v9Skk27p4zDq6j for ; Sat, 28 Jan 2017 19:00:29 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=aj.id.au header.i=@aj.id.au header.b="AV5TPadc"; dkim=pass (1024-bit key; unprotected) header.d=messagingengine.com header.i=@messagingengine.com header.b="gT6HVbBG"; dkim-atps=neutral Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id 417C6209BC for ; Sat, 28 Jan 2017 03:00:25 -0500 (EST) Received: from frontend2 ([10.202.2.161]) by compute4.internal (MEProxy); Sat, 28 Jan 2017 03:00:25 -0500 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=aj.id.au; h= content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to:x-me-sender:x-me-sender:x-sasl-enc :x-sasl-enc; s=mesmtp; bh=SbvkOz5hwqqv42srAEai1Z6aFCE=; b=AV5TPa dcuIuWKl78NepyWDzNRPrlwf2E7jmWb/+z0eCYvSTPOhaIsUX/ksw6wLhB1ZoLTI YGeiVc2jLyassVq1S7pguLLs5zfCUyVC8ExJLLOjAA1b1YWmsgNHkUE14FyzN1EU LY5jQG5kKZK+Bx34Rb+bF/wIk5DzhUKx4gWPw= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc:x-sasl-enc; s=smtpout; bh=SbvkOz5hwqqv42 srAEai1Z6aFCE=; b=gT6HVbBGO8JPW77oW8NuutjMaGPV19fS7UcUFiIA6CwixZ WC5dnit3IGV/bFrJ7Q5/8m5tShBlbd57vIadAaorGpGP/ch2ZhARQSbrFzlSj+hH rb7zWN0fQGk2noruO1ZkM4HgSGqGQtgiyhY3NVqp3+2/XwjJOtiNBKGk5cOy4= X-ME-Sender: X-Sasl-enc: xfyHJM8l+apQYNQWSd067Z31huPR+CvbLIBTtdCk5lH2 1485590424 Received: from lasair.aj.id.au (ppp203-122-213-247.static.internode.on.net [203.122.213.247]) by mail.messagingengine.com (Postfix) with ESMTPA id 1FA81244B4 for ; Sat, 28 Jan 2017 03:00:23 -0500 (EST) Message-ID: <1485590413.2450.7.camel@aj.id.au> Subject: Re: [PATCH linux v2] arm: aspeed: zaius: Disable LPC reset for UART1 From: Andrew Jeffery To: openbmc@lists.ozlabs.org Date: Sat, 28 Jan 2017 18:30:13 +1030 In-Reply-To: References: <20170127232307.110483-1-xow@google.com> Content-Type: multipart/signed; micalg="pgp-sha384"; protocol="application/pgp-signature"; boundary="=-0Go/DIx4elNzceJo3Km/" X-Mailer: Evolution 3.20.5 Mime-Version: 1.0 X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 28 Jan 2017 08:00:31 -0000 --=-0Go/DIx4elNzceJo3Km/ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2017-01-27 at 15:32 -0800, Rick Altherr wrote: > I still don't follow.=C2=A0 Is this changing it to drop bytes until the > host powers on?=C2=A0 Is this change making it so the device won't open? I understand it to be the other way around:=C2=A0 In the existing configuration UART1 will drop bytes by being held in reset until the host initialises the LPC bus (i.e. releases LPCRST#) during boot. Xo's change reconfigures the SoC so that UART1 reset state doesn't depend on LPCRST# (i.e. the host initialising the LPC bus), so it is immediately useful in that it won't discard bytes. Xo? Andrew >=20 > > On Fri, Jan 27, 2017 at 3:23 PM, Xo Wang wrote: > > Currently, UART1 on Zaius BMC is unusable until brought out of reset by > > powering the host on. In this reset state, ttyS0 can still be opened > > and UART1 silently drops bytes, which is not obviously expected > > behavior. > >=20 > > Clear the LPC block control bit that enables LPCRST# as a reset source > > for UART1. > >=20 > > Signed-off-by: Xo Wang > --- > > =C2=A0arch/arm/mach-aspeed/aspeed.c | 7 +++++++ > > =C2=A01 file changed, 7 insertions(+) > >=20 > > diff --git a/arch/arm/mach-aspeed/aspeed.c b/arch/arm/mach-aspeed/aspee= d.c > > index 4bd3680d742d..fa99d8bde5e0 100644 > > --- a/arch/arm/mach-aspeed/aspeed.c > > +++ b/arch/arm/mach-aspeed/aspeed.c > > @@ -185,6 +185,13 @@ static void __init do_zaius_setup(void) > >=20 > > =C2=A0 =C2=A0 =C2=A0 =C2=A0 /* Set SPI1 CE0 decoding window to 0x300000= 00 */ > > =C2=A0 =C2=A0 =C2=A0 =C2=A0 writel(0x68600000, AST_IO(AST_BASE_SPI | 0x= 30)); > > + > > +=C2=A0 =C2=A0 =C2=A0 =C2=A0/* Disable LPC reset for UART1, otherwise h= eld in reset by LPCRST#, > > +=C2=A0 =C2=A0 =C2=A0 =C2=A0 * silently dropping bytes until released (= usually by host power on) > > +=C2=A0 =C2=A0 =C2=A0 =C2=A0 * */ > > +=C2=A0 =C2=A0 =C2=A0 =C2=A0reg =3D readl(AST_IO(AST_BASE_LPC | 0x98)); > > +=C2=A0 =C2=A0 =C2=A0 =C2=A0/* Clear "Enable UART1 reset source from LP= C" */ > > +=C2=A0 =C2=A0 =C2=A0 =C2=A0writel(reg & ~BIT(4), AST_IO(AST_BASE_LPC |= 0x98)); > > =C2=A0} > >=20 > > =C2=A0static void __init do_witherspoon_setup(void) > > -- > > 2.11.0.483.g087da7b7c-goog > >=20 > > _______________________________________________ > > openbmc mailing list > > openbmc@lists.ozlabs.org > > https://lists.ozlabs.org/listinfo/openbmc > >=20 >=20 > _______________________________________________ > openbmc mailing list > openbmc@lists.ozlabs.org > https://lists.ozlabs.org/listinfo/openbmc --=-0Go/DIx4elNzceJo3Km/ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQIcBAABCQAGBQJYjE+OAAoJEJ0dnzgO5LT5CWgQAJfqxpTZ6zuHREBvP1g/vFVB 5g+poEylV0/NR+xRj7O3z9AN32nYG1UyVSbkGzNkDDDdFcOiJuxzPlggf+i9Vk5H iwJSSEpp8tuqmr8DuXCzLyxKQKnwUvMJAPTUNMarLlF/7etZslUL+3lRmTICdeC6 IovG1RlKikitF9U/JcHmjo8P8Mm0poWnN7TwwS77Gs/Er1SjTNPLG3587YFDok5D Zc2WFBXaqy5Ho7sfM4Vylpg2HOiXpM+rlXGJCyIHG+O75yE/JcAUeW2qQ7wca83a E/SqFOA8zmybe9FE9UlYOaqDk2fYMeyc8nIA489u8AE9t1VWV5x10zDsQxCHfhmN FbeyOnkgFNfOgHcTNT308oqcwMFctsRCG+0kd7c33JVXsAMbZy98fO7QtoanzKV4 LgrSgSIW38iwCidUF75y+1yJftfeclDV3yyKplHvHfxlHZJSFz4CETaG3pvh+huc 2RGON/ThJfOIv2ijDmXSk27VXQ1re5BGZcQEtEnrV019yv8hKeAVWmaYMmRGBEHL VOspBNw0rJSBAXHETN5aCOSJXgUntmPw0tBTZ78NFnuOFqbw1JyY020RBhCikP4C iEjM71aCP6UlsrQ0ZWPlP+SUuK/48d6ntIO2zT7osw9fBlhmZout4GIlFpZn2FzP iSs1qXUqwos6vTSclHeN =NURx -----END PGP SIGNATURE----- --=-0Go/DIx4elNzceJo3Km/--