From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49cNv0gPWxocwUnpfZZPZ76TK3blUb4HxIo2/4kafwBiiv3ApTUKlDPJi+ezXGEDyn/wXhQ ARC-Seal: i=1; a=rsa-sha256; t=1524204199; cv=none; d=google.com; s=arc-20160816; b=Io58eO2RVetWVRonCqOGsya93Cclhq/S7nbhwfeb/0xrX661hl3zfEeqCI0N+ufQMl NWSEKd1eAo9WIdUnMMq8UVsQkT0xGDkHaqMbrDk6Wh9iSjGmRvL/1bQJ9yDNryxqRTTy xo4j8RTBWK9uQTAgKlaZHvK4XBH2GNfGoEdbeZsUQdu6QYoiBy/IvcAmHfSYAin7YHWU coFJACBJvV4FTNbtzGLq2LTjne/Y945l9oLwRRcN1zS0H7g1mfnNwFu0Lp85P38YD2jw tw6744rSgzMYuynK+inscxBHe+6N1038VobWNgad65fK/TYcvuuSwGzWR/ZZVki/T1qj Z8Nw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-transfer-encoding :content-disposition:mime-version:references:message-id:subject:cc :to:from:date:arc-authentication-results; bh=yxtsdL29EdlW6eV0VyxgVS4OoWz5N4Unp8/ty6GkVzA=; b=cbFZOs86Lw7VcqReaD++sZVd2bBugFO8nToAmqA/D6SvFg9pJjHr9ghvXe5mCfXHcU D/iVoqHQZHjfYRcMOKs0wdk356kkjmKBw7WvxHpu89O5Gv7lP08opBqhTz5jQ7Ck/xuQ 0UvCVKg0+dfWJWd4Ysi5VuEn4dWmTL8ZCfz6UsLfzQBpAX4+dQhLR1ayzwod60LLZ/A8 Ow20ve5yH9Qw52evacpYIpLEDD7QdCoUVWzJfWIbMo5rHVY/IV73ooc80uRlGtOjHN68 put4WDzr2poG8Zrhr0eNA5n87+WjRHuJO30RtjZa/BDzGiCBGlzqjq7H7K+djqahLux9 xrxQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of ukl@pengutronix.de designates 2001:67c:670:201:290:27ff:fe1d:cc33 as permitted sender) smtp.mailfrom=ukl@pengutronix.de Authentication-Results: mx.google.com; spf=pass (google.com: domain of ukl@pengutronix.de designates 2001:67c:670:201:290:27ff:fe1d:cc33 as permitted sender) smtp.mailfrom=ukl@pengutronix.de Date: Fri, 20 Apr 2018 08:03:15 +0200 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Stefan Agner Cc: gregkh@linuxfoundation.org, jslaby@suse.com, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] serial: imx: fix cached UCR2 read on software reset Message-ID: <20180420060315.ob6eygfcibwq7f24@pengutronix.de> References: <20180416153502.11814-1-stefan@agner.ch> <581f0f26d7191aa3355a6c63b531f876@agner.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <581f0f26d7191aa3355a6c63b531f876@agner.ch> User-Agent: NeoMutt/20170113 (1.7.2) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c5 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: gregkh@linuxfoundation.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597917613675943799?= X-GMAIL-MSGID: =?utf-8?q?1598243942704456369?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Hello Stefan, On Thu, Apr 19, 2018 at 11:37:23PM +0200, Stefan Agner wrote: > On 16.04.2018 17:35, Stefan Agner wrote: > > To reset the UART the SRST needs be cleared (low active). According > > to the documentation the bit will remain active for 4 module clocks > > until it is cleared (set to 1). > > > > Hence the real register need to be read in case the cached register > > indcates that the SRST bit is zero. > > > > This bug lead to wrong baudrate because the baud rate register got > > restored before reset completed in imx_flush_buffer. > > Given that you reviewed my other patch rather quickly, you might have > overlooked this one? no I didn't, still the ping was justified. I didn't look into it at once because I didn't feel like opening the refman. > Since it is a regression, this should go into v4.17 still... That's right, Reviewed-by: Uwe Kleine-König I wonder what is different on your side that made it break. I didn't see any breakage and tested that on a handful of different machines. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |