From owner-freebsd-current@FreeBSD.ORG Tue Oct 8 01:58:48 2013 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 5043E8DC; Tue, 8 Oct 2013 01:58:48 +0000 (UTC) (envelope-from ganbold@gmail.com) Received: from mail-ie0-x236.google.com (mail-ie0-x236.google.com [IPv6:2607:f8b0:4001:c03::236]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 04872270F; Tue, 8 Oct 2013 01:58:47 +0000 (UTC) Received: by mail-ie0-f182.google.com with SMTP id aq17so18237126iec.27 for ; Mon, 07 Oct 2013 18:58:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=kWH4GdJb+ZdwhDxl2PYsTGVFhxMbroOQ0jREJprwDn0=; b=jMfh3sPzsDHJf1LYgPMsTee1FVm2znvYnTSgqBHHwzRkrMDcvguJbI7WisXdHi8803 +k8Ofy7vVAaQWZ2sEVkz20iYQBz+tabsPx6RQVuDn6m2Kz8W9Dnei2FV2i7X7ru+v5rh 8LNFW84g28zakTkc40WLeX5mTN53V9WmzzGDSkODcrJRAi1JqiKozq0ZUqX9oFzT/l2g eihiaQnGDI+U90pE72YibdoFfr1Vi+miRh7N4XQi8joA1Sg4HL0kpc72bFzZfEYtsKja NGCKoZKUWZ8TL2x9MvCK+gxtz7ImfBAudLdsQ8tklqGRYz5KGQ2W3E0XR0Cpz6UcdeBm Qs/A== MIME-Version: 1.0 X-Received: by 10.50.30.42 with SMTP id p10mr19339045igh.5.1381197527427; Mon, 07 Oct 2013 18:58:47 -0700 (PDT) Received: by 10.65.14.133 with HTTP; Mon, 7 Oct 2013 18:58:47 -0700 (PDT) In-Reply-To: References: Date: Tue, 8 Oct 2013 09:58:47 +0800 Message-ID: Subject: Re: Changes to UART ns8250 From: Ganbold Tsagaankhuu To: Zbigniew Bodek Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.14 Cc: "freebsd-arm@freebsd.org" , freebsd-current@freebsd.org, freebsd-embedded@freebsd.org X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Oct 2013 01:58:48 -0000 Zbigniew, On Tue, Oct 8, 2013 at 3:54 AM, Zbigniew Bodek wrote: > Hello. > > I would like to present a patch for ns8250 serial that I would like to > commit in the near future (if there are no objections). > > The patch is fixing newest DesignWare UART with busy detection. > During frequency divisors configuration when UART is busy transferring or > receiving data, line control register manipulation will not take effect. > Therefore, we will not set divisor latch access bit and we will corrupt LCR > instead of configuring divisors. > It is necessary to wait until UART finishes all transfers to proceed with > the configuration. > > This was detected on Armada XP as UART fails on this issue 100/100 > attempts. > The patch was tested by kevlo@ and me and it works on our Armada XP - > based > systems. > > Please send your comment or remarks if there are any. > I'm trying your patch on r254983. Tried on 2 boards (Cubieboard2 (Allwinner A20 SoC - dual Cortex A7) and Radxa Rock (Rockchip RK3188 - Quad Cortex A9)). Both seem to have some sort of DesignWare uart. 1. It works fine on Cubieboard2. Uart dmesg is like: uart0: <16750 or compatible> mem 0x1c28000-0x1c283ff irq 33 on simplebus0 uart0: console (115200,n,8,1) 2. No any printing on screen in case of Radxa Rock. Without your patch uart dmesg is like: uart0: <16650 or compatible> mem 0x20064000-0x200643ff irq 68 on simplebus0 uart0: console (115200,n,8,1) In case of RK3188 SoC, it seems booting FreeBSD kernel seems very fragile, not sure yet what is causing the problem. Even with stock ns8250 some version later than r254983 didn't show/print anything on serial console few days ago. Only thing so far I know is this r254983 (with some patch) works in my case on RK3188 SoC based board. thanks, Ganbold > > Best regards > Zbigniew Bodek > > _______________________________________________ > freebsd-current@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org" >