From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1755317AbcETC03 (ORCPT <rfc822;w@1wt.eu>);
	Thu, 19 May 2016 22:26:29 -0400
Received: from ozlabs.org ([103.22.144.67]:32837 "EHLO ozlabs.org"
	rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
	id S1753441AbcETC01 (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Thu, 19 May 2016 22:26:27 -0400
Subject: Re: [PATCH] fbcon: warn on invalid cursor blink intervals
To: Ming Lei <ming.lei@canonical.com>, Scot Doyle <lkml14@scotdoyle.com>
References: <1463510464-28124-1-git-send-email-ddaney.cavm@gmail.com>
 <20160517204912.GA29719@amd>
 <CACVXFVPdjfFkRFucTQsOHsVFtgm1W0JtOTqjyDzyNbzygghUyg@mail.gmail.com>
 <alpine.DEB.2.10.1605181519540.8967@laptop>
 <ed8fa4ca-49e0-3ff4-5499-fc5250dd8ae2@caviumnetworks.com>
 <alpine.DEB.2.10.1605182252230.12118@laptop>
 <573DE2D0.1050402@caviumnetworks.com>
 <alpine.DEB.2.10.1605191708400.15396@laptop>
 <alpine.DEB.2.10.1605191726030.15478@laptop>
 <CACVXFVM77CaHGE9kwhaxoa-fuNxZrDDzpCdHfnRno857pQANZQ@mail.gmail.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>,
        Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>,
        David Daney <david.daney@cavium.com>,
        Dann Frazier <dann.frazier@canonical.com>,
        Peter Hurley <peter@hurleysoftware.com>, Pavel Machek <pavel@ucw.cz>,
        Jonathan Liu <net147@gmail.com>,
        Alistair Popple <alistair@popple.id.au>,
        Jean-Philippe Brucker <jean-philippe.brucker@arm.com>,
        "Chintakuntla, Radha" <Radha.Chintakuntla@caviumnetworks.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jslaby@suse.com>, David Airlie <airlied@linux.ie>,
        David Daney <ddaney.cavm@gmail.com>, dri-devel@lists.freedesktop.org,
        linux-fbdev@vger.kernel.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        stable <stable@vger.kernel.org>
From: Jeremy Kerr <jk@ozlabs.org>
Message-ID: <573E75CD.6050202@ozlabs.org>
Date: Fri, 20 May 2016 10:26:21 +0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.7.2
MIME-Version: 1.0
In-Reply-To: <CACVXFVM77CaHGE9kwhaxoa-fuNxZrDDzpCdHfnRno857pQANZQ@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi Ming,

> Not sure this one is needed for stable because it justs dumps
> a warning, and not set a valid period to ops->cur_blink_jiffies.
> 
> So I guess other fix patch is still required for the soft lockup
> issue, right?

The main thing is that we don't set cur_blink_jiffies to the < 50ms
value. As far as I can tell, it means we'll still get the original
default, set in fbcon_startup():

	ops->cur_blink_jiffies = HZ / 5;

And so don't end up spinning on the timer expiry.

Cheers,


Jeremy