From: Nick Bowler <nbowler@draconx.ca>
To: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
intel-gfx@lists.freedesktop.org
Subject: Re: PROBLEM: Intel VGA output busticated on 4.3-rc2 (regression)
Date: Wed, 7 Oct 2015 10:29:22 -0400 [thread overview]
Message-ID: <CADyTPEzhNppBWFkFGSy5cVYybKQfQFZogf2sYs2CTMfQE1duJw@mail.gmail.com> (raw)
In-Reply-To: <20151007115850.GE26517@intel.com>
On 10/7/15, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> On Tue, Oct 06, 2015 at 11:42:33AM -0400, Nick Bowler wrote:
>> On 9/24/15, Nick Bowler <nbowler@draconx.ca> wrote:
>> > Testing out 4.3-rc2, first thing I notice is that the VGA output is
>> > not working. Specifically, the display is continuously powering on
>> > and off -- at no point is any image visible on the screen (I am
>> > expecting to see the console output). The display connected to the
>> > HDMI output is working fine.
[...]
>> b8afb9113c519a8bd742f7df8c424b0af69a75cd is the first bad commit
>> commit b8afb9113c519a8bd742f7df8c424b0af69a75cd
>> Author: Ville Syrjälä <ville.syrjala@linux.intel.com>
>> Date: Mon Jun 29 15:25:48 2015 +0300
>>
>> drm/i915: Keep GMCH DPLL VGA mode always disabled
[...]
> @@ -1790,13 +1790,13 @@ static void i9xx_disable_pll(struct intel_crtc
> *crtc)
> /* Make sure the pipe isn't still relying on us */
> assert_pipe_disabled(dev_priv, pipe);
>
> - I915_WRITE(DPLL(pipe), 0);
> + I915_WRITE(DPLL(pipe), DPLL_VGA_MODE_DIS);
> POSTING_READ(DPLL(pipe));
> }
>
>
> That hunk is the only relevant part for your machine. Can you try to revert
> just that manually?
>
> But I'm really surprised that would have any effect since we only used
> to enable "VGA mode" when the DPLL is off. And when the DPLL is off,
> there's nothing on the screen anyway.
Nevertheless, manually reverting just that hunk seems to fix it.
Thanks,
Nick
next prev parent reply other threads:[~2015-10-07 14:29 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-24 21:22 PROBLEM: Intel VGA output busticated on 4.3-rc2 (regression) Nick Bowler
2015-09-25 12:25 ` Daniel Vetter
2015-10-06 15:42 ` Nick Bowler
2015-10-07 11:58 ` Ville Syrjälä
2015-10-07 14:29 ` Nick Bowler [this message]
2015-10-07 15:32 ` Ville Syrjälä
2015-10-07 15:44 ` Nick Bowler
2015-10-07 15:47 ` Nick Bowler
2015-10-07 18:50 ` Nick Bowler
2015-10-07 19:04 ` Ville Syrjälä
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