From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-x22f.google.com (mail-qt0-x22f.google.com [IPv6:2607:f8b0:400d:c0d::22f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3v9FHc1CYlzDq60 for ; Sat, 28 Jan 2017 10:24:44 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="U8QodaVw"; dkim-atps=neutral Received: by mail-qt0-x22f.google.com with SMTP id v23so160485739qtb.0 for ; Fri, 27 Jan 2017 15:24:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=UX+J7mc1SPu3EuvMno9n3ZUzwjOeX5Ikn+8gAuej0so=; b=U8QodaVwLKKfAzIU/C7OzJ9HSFs1w7PpiEyxvGLL40116uc2bxjUOlZkNXiXF1TAv5 SeiAx397XQ+wXlLsdJaETej+kOv9njCxkBjrCvhl3/bSJoI5bEisGc6yyD1iQDG1I4ih zBHEjcYJfeqq8atcPXAY9Pp2jfv0vNkt2JTu/P/ViqlgXTwKEojHQ/d2HqU59Rma3fgO 6JjiPPvNAhX3wyw+lIXu9NZrhcmWAarQXDmzA/Gg2+ZGwjrWF+2mH+nxzDHaBnrKdgvn 19r7wURQik2zwjJchi0A7SQ+iwF5OdgsEL6dk+xJpEo5mdHXLoa0yYsGG2jDHX0JGxxC lKbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=UX+J7mc1SPu3EuvMno9n3ZUzwjOeX5Ikn+8gAuej0so=; b=oNDqe4rFy9NfrYCn/4AYseeC+jr5TTRX2R8lZ4ZtVSP9hCuWrOycxbyDc65g3CmoxG QQ6dFJEDggJ0ro4csSIXo4C+Yrm4kL4asP2YIxc2/XI52NqXaifxhJQW7rZ70VFXUWH0 V/H2iwfLXgCSczviX7HTX8WWK9xBU86wyP7lQ7RUoLUs51k1+OoIZgKrHnttvi8NH1+b eDnWZz8iY99zIyR+zaqdml4aSIx+uua8SfIvuyT6TDPjVbqrXyXCPWmxFOdQvJ1oeDIl F9cx81z0teUdWKiqrB47iLWSben9oWVksWtrFJF2YxtzZxh+/aLcRHpUo4RZzT3Sgc/s 93OA== X-Gm-Message-State: AIkVDXL0spvdnAyxiP8Hq5obesEZJBcUasXYwfRV7tFIi4E8h2SIW5ZJoAfIRXQmayd4Rha4d5LrgZx16nmkvzpd X-Received: by 10.237.60.49 with SMTP id t46mr10995599qte.140.1485559481268; Fri, 27 Jan 2017 15:24:41 -0800 (PST) MIME-Version: 1.0 Received: by 10.140.21.116 with HTTP; Fri, 27 Jan 2017 15:24:40 -0800 (PST) In-Reply-To: References: <20170127170814.120771-1-xow@google.com> From: Xo Wang Date: Fri, 27 Jan 2017 15:24:40 -0800 Message-ID: Subject: Re: [PATCH linux] arm: aspeed: zaius: Disable LPC reset for UART1 To: Rick Altherr Cc: OpenBMC Maillist Content-Type: text/plain; charset=UTF-8 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: Fri, 27 Jan 2017 23:24:44 -0000 Heh, that's fair. I guess the code is an opaque block of bit twiddling. Please take a look at v2. On Fri, Jan 27, 2017 at 9:41 AM, Rick Altherr wrote: > From the patch, I can't tell what your change is doing. You've described > the problem but not the solution. > > On Fri, Jan 27, 2017 at 9:08 AM, 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. >> >> Signed-off-by: Xo Wang > --- >> arch/arm/mach-aspeed/aspeed.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/arch/arm/mach-aspeed/aspeed.c b/arch/arm/mach-aspeed/aspeed.c >> index 4bd3680d742d..9f06191f1630 100644 >> --- a/arch/arm/mach-aspeed/aspeed.c >> +++ b/arch/arm/mach-aspeed/aspeed.c >> @@ -185,6 +185,10 @@ static void __init do_zaius_setup(void) >> >> /* Set SPI1 CE0 decoding window to 0x30000000 */ >> writel(0x68600000, AST_IO(AST_BASE_SPI | 0x30)); >> + >> + /* Disable LPC reset for UART1 */ >> + reg = readl(AST_IO(AST_BASE_LPC | 0x98)); >> + writel(reg & ~BIT(4), AST_IO(AST_BASE_LPC | 0x98)); >> } >> >> static void __init do_witherspoon_setup(void) >> -- >> 2.11.0.483.g087da7b7c-goog >> >> _______________________________________________ >> openbmc mailing list >> openbmc@lists.ozlabs.org >> https://lists.ozlabs.org/listinfo/openbmc > >