Re: [PATCH 03/21] drm/i915: Remove extra 300ms delay during eDP modesetting

[Daniel Vetter]

On Fri, Sep 30, 2011 at 10:50:10AM -0700, Keith Packard wrote:
> On Fri, 30 Sep 2011 18:27:28 +0200, Daniel Vetter <daniel@xxxxxxxx> wrote:
> 
> > Can you elaborate a bit why this is no longer needed? Jesse seems to have
> > introduced this spefically for edp panels in d209848d61794968. If this
> > becomes rendundant due to your panel power sequencing fixes, maybe move it
> > down the series?
> 
> The only reason for this delay is to avoid some potential noise on the
> screen during mode setting, all of the power sequencing delays are
> already correctly managed by the driver. As far as I can tell, we're
> trading off the small potential for noise on the screen with an extra
> 300ms delay at boot time.
> 
> In the eDP spec, there's a delay listed (T8) between the start of video
> data and turning on the backlight. There are no values presented and
> the instructions are simply that the source is supposed to wait until
> the display is stable. I'm not sure how we'd ever know that the display
> is stable.

Ok, maybe add the above to paragraphs to the commit msg. Then
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
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Daniel Vetter
Mail: daniel@xxxxxxxx
Mobile: +41 (0)79 365 57 48
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