Re: [gentoo-user] black screen on boot when udevevents are processed

lee <lee@××××××××.de> wrote:

> <wabenbau@×××××.com> writes:
>
> > lee <lee@××××××××.de> wrote:
> >
> >> <wabenbau@×××××.com> writes:
> >>
> >> > lee <lee@××××××××.de> wrote:
> >> >
> >> >> Hi,
> >> >>
> >> >> I'm getting a black screen during booting, with the last
> >> >> message I can see being that udevevents are being processed.
> >> >>
> >> >> This happens with an NVIDIA GTX770 connected to a 4k display
> >> >> via a display port cable, and only when the monitor is
> >> >> configured to use display port 1.2 rather than 1.1.  With 1.1,
> >> >> I can get only 30Hz refresh rate, so I want to use 1.2, which
> >> >> should allow 60.
> >> >>
> >> >> Installed are nvidia-drivers 343.36.
> >> >>
> >> >> Do I need a very special display port cable for this, or what
> >> >> might the issue?  Both the graphics card and the monitor should
> >> >> be able to do the full resolution at 60Hz just fine.
> >> >
> >> > You need a DP cable that is able to handle a resolution of
> >> > 4k@60Hz. Not all DP cables can do this.
> >>
> >> Hm, I bought this cable today, so I'd think it should be ok ---
> >> but I didn't explicitly specify that it must be one that does
> >> 4k@60.  I didn't know I might have to.
> >>
> >> Is there any way to tell?  The sticker on the package only says
> >> DP/DP 2.0m.
> >
> > It should be certified to DP 1.1a at least.
> >
> > Excerpt from
> >
> > https://web.archive.org/web/20140327103747/http://www.displayport.org/faq/
> >
> > ----
> >
> > Q: Where can I buy a DP 1.2 cable? Most of the cables are certified
> > to DP 1.1a.
> >
> > A: The DisplayPort version 1.2 standard was designed to utilize the
> > Standard Display cable. We did this intentionally to avoid customer
> > confusion. A DisplayPort cable is a DisplayPort cable; EXCEPT if it
> > a “reduced bit rate” (or RBR) cable, which is typically a 15m cable
> > designed for projector applications, and they only support up to
> > 1080P; OR if it is an active cable, which will not support the new
> > HBR2 rate introduced in the DP 1.2 standard.
> >
> > So a cable that was tested to meet the DP 1.1a requirments also
> > meets the DP 1.2 requirements.
> >
> > ----
> >
> > But this is theory. I've made the experience that some cables
> > doesn't work with 4k@60Hz although they are so-called 1.1a/1.2
> > certified. I've bought four faulty cables before I found the two
> > that I'm using now. One of the faulty cables doesn't work at all at
> > full resolution, the others are working but the picture had a lot
> > of errors and was sometimes black for some seconds.
> >
> > The two cables which I'm using now are a CROMO 41532 (2m length)
> > and a CROMO 41533 (3m length).
> >
> > Do you have the opportunity to test the cable with some other
> > system, e.g. some live system (knoppix?) or some windows system? I
> > would do this first before buying a new cable.
>
> Thank you very much for all the info!
>
> I finally got a cable that works.  It's from Delock and says 82771 on
> the back of the package where the EAN code is.  I like it, it seems to
> be good quality, and most importantly, it works.

Then you really had luck. I had two faulty cables from Delock and I
decided not to buy a cable from Delock again.
 
> However, I can see the BIOS and the boot manager menu, then during
> booting, the screen goes black and the monitor says "no signal"
> (probably when the nvidia module is loaded).  So I logged in blindly
> and started X11 and got a picture again.
>
> The monitor info says 4k@60Hz in the BIOS and when X11 is running.  So
> there must be some setting which causes the graphics card to blank out
> on the console.
>
> Any idea what that could be?

That's strange. I would understand a message like "Frequencies out of 
range" or something like that. But "No signal" indicates, that the 
monitor gets no signal at all. 

What happens when you switch from X to text console (Alt + Strg + F1)?

--
Regards
wabe