From: Jani Nikula <jani.nikula@linux.intel.com>
To: 陳勇秀 <greatshow.chen@gmail.com>, intel-gfx@lists.freedesktop.org
Subject: Re: No display at boot
Date: Tue, 23 Sep 2014 15:41:00 +0300 [thread overview]
Message-ID: <87tx3y5x2b.fsf@intel.com> (raw)
In-Reply-To: <CAJ6_vb3ObrEqhaVO2d8bLaP7=ampF_qGueXYG5T7zQw4bkPjEQ@mail.gmail.com>
On Tue, 23 Sep 2014, 陳勇秀 <greatshow.chen@gmail.com> wrote:
> Hi All,
>
> I am using a baytrail cpu and linux kernel 3.14.7, and will echo some
> message to /dev/tty1 during boot.
>
> There is chance that no display output during boot, but I can use linux via
> ttyS4, the HSUART.
>
> Attached is output of intel_reg_dumper,
> display.fail is register dump that no display output.
> display_ok is register dump that display works.
>
> There is difference between:
>
> DPLL_A_MD: 0x60ff2cdf (ok)
> DPLL_A_MD: 0x70ff2ddf (fail)
>
> DPLL_B: 0x60ff2cdf (disabled, dvo, VGA, TV A clock, unknown mode, p1 = 1,
> p2 = 0) (ok)
> DPLL_B: 0x70ff2ddf (disabled, dvo, TV A clock, unknown mode, p1 = 1, p2 =
> 0, using FPx1!) (fail)
>
> The bios dump is also attached. How do I read the bios dump file?
>
> The problem can be reproduced even I update kernel to 3.14.18.
>
>
> It's interesting the no display issue never happens if I boot into x-window
> system.
Please file a bug against DRM/Intel at [1], attach dmesg all the way
from boot to the problem with drm.debug=14 module parameter set.
BR,
Jani.
[1] https://bugs.freedesktop.org/enter_bug.cgi?product=DRI
--
Jani Nikula, Intel Open Source Technology Center
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
prev parent reply other threads:[~2014-09-23 12:41 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-23 2:49 No display at boot 陳勇秀
2014-09-23 12:41 ` Jani Nikula [this message]
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=87tx3y5x2b.fsf@intel.com \
--to=jani.nikula@linux.intel.com \
--cc=greatshow.chen@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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.