Date: Mon, 4 Dec 2017 14:30:01 -0500
From: Nick Bowler <nbowler@draconx.ca>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Archit Taneja <architt@codeaurora.org>, linux-kernel@vger.kernel.org,
        dri-devel@lists.freedesktop.org,
        Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Dave Airlie <airlied@redhat.com>, Andrzej Hajda <a.hajda@samsung.com>
Subject: Re: PROBLEM: Asus C201 video mode problems on HDMI hotplug
 (regression)
Message-ID: <20171204193001.dduxkafufgpeexk2@aura.draconx.ca>
References: <CADyTPEyatxOS0z3-4fapUiuxhPsp0985YcQvgFvdp_Pesm1idg@mail.gmail.com>
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Hi,

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.

Cheers,
-- 
Nick Bowler