From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: PROBLEM: Asus C201 video mode problems on HDMI hotplug (regression) Date: Mon, 04 Dec 2017 21:34:36 +0200 Message-ID: <2033574.q3E8txTlp8@avalon> References: <1710500.fZbdeDGCTu@avalon> <20171204193001.dduxkafufgpeexk2@aura.draconx.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20171204193001.dduxkafufgpeexk2@aura.draconx.ca> Sender: linux-kernel-owner@vger.kernel.org To: Nick Bowler Cc: Archit Taneja , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Laurent Pinchart , Linus Torvalds , Dave Airlie , Andrzej Hajda List-Id: dri-devel@lists.freedesktop.org Hi Nick, On Monday, 4 December 2017 21:30:01 EET Nick Bowler wrote: > On 2017-12-04 21:06 +0200, Laurent Pinchart wrote: > > As you reported that the PLL lock failure message is not printed, the > > failure can only come from either the extra delay introduced by the > > above loop, or from reading the HDMI_PHY_STAT0 register. > > > > How many iterations of the for loop execute before the condition > > becomes true? > > Judging from the log posted elsethread (where I added extra printouts), > it seems to consistently become true on the second iteration. > > I will try to rule out read side effects by replacing the polling loop > with an unconditional delay. You're reading my mind :-) -- Regards, Laurent Pinchart