From: Daniel Vetter <daniel@ffwll.ch>
To: Dave Airlie <airlied@gmail.com>
Cc: "intel-gfx@lists.freedesktop.org" <intel-gfx@lists.freedesktop.org>
Subject: Re: limiting modes on 4k monitors on Haswell ULT
Date: Thu, 2 Oct 2014 10:00:50 +0200 [thread overview]
Message-ID: <20141002080050.GU12343@phenom.ffwll.local> (raw)
In-Reply-To: <CAPM=9tye0vGi1999_XXh1u6P49uqvMr=-qVQENJXk4Y0U49Q-A@mail.gmail.com>
On Thu, Oct 02, 2014 at 01:30:48PM +1000, Dave Airlie wrote:
> Hey guys,
>
> so I have a haswell ULT laptop (lenovo t440s), and got access to a
> Samsung single panel 4k monitor (no MST).
>
> Now we detect the monitor fine, but unfortunately the ULT hsw can't
> run it over DP, as it has clock limits in place. However we still
> offer the 60hz mode and we pick it by default, ensuing black screens.
>
> I've tested the same monitor with a haswell in a t540p and it works
> fine due to having the higher limits in place.
We have the IS_HSW_ULX check in intel_dp_max_link_bw, and that's used by
both compute_config and mode_valid. So it should work, and from a quick
look I don't see any bugs. But obviously something is busted.
Can you please printk-augment intel_dp_mode_valid and check what's going
wrong there?
Thanks, Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
next prev parent reply other threads:[~2014-10-02 8:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-02 3:30 limiting modes on 4k monitors on Haswell ULT Dave Airlie
2014-10-02 8:00 ` Daniel Vetter [this message]
2014-10-02 8:40 ` Ville Syrjälä
2014-10-02 10:56 ` Dave Airlie
2014-10-07 13:07 ` Ville Syrjälä
2014-10-02 11:15 ` Damien Lespiau
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20141002080050.GU12343@phenom.ffwll.local \
--to=daniel@ffwll.ch \
--cc=airlied@gmail.com \
--cc=intel-gfx@lists.freedesktop.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox