[Bug 98046] New: iMac11,1 (RV770/M98L [Mobility Radeon HD 4850]) needs nomodeset to boot

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

Bug ID: 98046
Summary: iMac11,1 (RV770/M98L [Mobility Radeon HD 4850]) needs
nomodeset to boot
Product: xorg
Version: unspecified
Hardware: x86-64 (AMD64)
OS: Linux (All)
Status: NEW
Severity: normal
Priority: medium
Component: Driver/Radeon
Assignee: xorg-driver-***@lists.x.org
Reporter: ***@jungers.net
QA Contact: xorg-***@lists.x.org

Created attachment 127000
--> https://bugs.freedesktop.org/attachment.cgi?id=127000&action=edit
Xorg.log of a failed boot

My iMac11,1 was running Ubuntu since the beginning and till 14.04 fine but gave
a black screen, with sometimes horizontal lines flowing since 15.04.

After applying the Apple patches Mac EFI Security Update 2015-002
(https://support.apple.com/kb/DL1848?locale=en_US) and 27-inch iMac SMC
Firmware Update 1.0 (https://support.apple.com/kb/DL1030?locale=en_US), my iMac
was unable to boot in graphical mode without the nomodeset kernel parameter.

Grub console is sluggish (but not for Ubuntu 11.10 and 12.04), sleep doesn't
work and overall graphic performances are bad.

I had to install OSX El Capitan for flashing the iMac and I didn't have issues
in OSX.

I join an Xorg.log of a failed boot (without nomodeset).

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

Alex Deucher <***@gmail.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
Attachment #127000|text/x-log |text/plain
mime type| |

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #1 from Alex Deucher <***@gmail.com> ---
Please attach your dmesg output. Was it the firmware updates the caused the
regression or an Ubunutu update? If it's an Ubuntu update, can you narrow down
what update caused the regression? If it's a firmware update, you'll probably
have to take that up with Apple.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #2 from Nicolas Jungers <***@jungers.net> ---
Created attachment 127003
--> https://bugs.freedesktop.org/attachment.cgi?id=127003&action=edit
dmesg output on 16.04

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

Alex Deucher <***@gmail.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
Attachment #127003|text/x-log |text/plain
mime type| |

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

James Cameron <***@laptop.org> changed:

What |Removed |Added
----------------------------------------------------------------------------
CC| |***@laptop.org

--- Comment #3 from James Cameron <***@laptop.org> ---
Created attachment 130894
--> https://bugs.freedesktop.org/attachment.cgi?id=130894&action=edit
dmesg of first failed commit

Same with another iMac11,1, but no firmware update. Kernels before 3.14 are
fine. Kernels from 3.14 show blank display or sometimes flickering horizontal
lines.

I've done a git bisect and first failing commit is
32167016076f714f0e35e287fbead7de0f1fb179 "drm/radeon: rework finding display
PLL numbers v2" by Christian König.

Happy to test kernels or enable debugging, let me know.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #4 from James Cameron <***@laptop.org> ---
Tested 4.11.0-rc7 as-is, and drm.debug=0xe, display was flickering horizontal
lines, and got PLL setup of;

[drm:radeon_compute_pll_avivo [radeon]] 360000 - 366660, pll dividers - fb:
22.0 ref: 2, post 3

Tested 4.11.0-rc7 by reverting all the PLL changes (overkill);

72edd83cc9e58 ("drm/radeon: fix PLLs on RS880 and older v2")
4b21ce1b4b5d2 ("drm/radeon: lower the ref * post PLL maximum once more")
3b333c55485f ("drm/radeon: avoid high jitter with small frac divs")
c2fb3094669a ("drm/radeon: improve PLL limit handling in post div calculation")
24315814239a ("drm/radeon: use fixed PPL ref divider if needed")
f8a2645ecede ("drm/radeon: improve PLL params if we don't match exactly v2")
32167016076f ("drm/radeon: rework finding display PLL numbers v2")

display was good, and got PLL setup of;

[drm:radeon_compute_pll_avivo [radeon]] 36000, pll dividers - fb: 54.0 ref: 5,
post 3

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #5 from Alex Deucher <***@gmail.com> ---
Created attachment 130899
--> https://bugs.freedesktop.org/attachment.cgi?id=130899&action=edit
possible fix

Does this patch help?

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

Alex Deucher <***@gmail.com> changed:

What |Removed |Added
----------------------------------------------------------------------------
Attachment #130899|0 |1
is obsolete| |

--- Comment #6 from Alex Deucher <***@gmail.com> ---
Created attachment 130900
--> https://bugs.freedesktop.org/attachment.cgi?id=130900&action=edit
possible fix

Narrow the focus to just rv770.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #7 from James Cameron <***@laptop.org> ---
Created attachment 130908
--> https://bugs.freedesktop.org/attachment.cgi?id=130908&action=edit
dmesg with "drm/radeon: adjust pll flags for RV770"

Thanks, but no, not fixed by 3cc2ebbca98 "drm/radeon: adjust pll flags for
RV770". Result was blank display. Captured dmesg by ssh, attached.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #8 from Justin Thiessen <***@gmail.com> ---
Hi,

I'm still seeing this issue with an iMac11,1 with the identical graphics
(RV770/M98L [Mobility Radeon HD 4850])

This is with kubuntu 17.04:

kernel: 4.10.0-32-generic

radeon driver info:
--------------------
libdrm-radeon1:amd64 2.4.76-1
xserver-xorg-video-radeon 1:7.9.0-0ubuntu1

I only get a working main display using 'nomodeset', which of course is
disabling the radeon driver.

Any suggested patches or things to try?

Thanks,

Justin Thiessen

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #9 from James Cameron <***@laptop.org> ---
Other than reverting the series in comment 4, I've no solution. Once I had
that workaround, I was mostly happy. I wanted to find the underlying problem
and upstream it, but ran out of time.

At one stage I was using "avivotool regs pll1" to confirm the PLL registers,
comparing between last working kernel version, latest kernel, and my kernel
with the series reverted.

My notes have outstanding questions that I didn't get to resolve;

1. how to achieve a dot clock of 360000 instead of 366660, given that 360000
works for me?

2. why is RADEON_PLL_PREFER_LOW_REF_DIV set given that the bit is only used
when RADEON_PLL_LEGACY is set?

3. why set RADEON_PLL_PREFER_MINM_OVER_MAXP given that it limits the ref_div to
7 yet the system has already chosen 2 instead of 5.

Hope that helps.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #10 from Justin Thiessen <***@gmail.com> ---
Thanks James - I'll give this a shot

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #11 from Justin Thiessen <***@gmail.com> ---
so with the reversions from comment 4 (some conflict resolution by hand
necessary, but seemed straightforward), the radeon driver loads and the primary
display gets initialized and seems to work.

seems like either:
* the screen dimming is broken resulting in a dark primary screen when that
kicks in

or

* after suspend the secondary display becomes primary and the internal screen
is dark.

haven't yet dug into this.

looks like i'm seeing occasional artifacts as well.

This is with kubuntu 17.04, kernel:

4.10.0-32-generic #36-Ubuntu SMP

Definitely progress, considering

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #12 from James Cameron <***@laptop.org> ---
Great. Sounds like what I observed. I seem to recall there were two sysfs
entries for brightness, and both were effective. I don't have automatic
dimming enabled, so didn't notice a problem. I don't suspend at all, because
it has never worked after resume. I'd forgotten to check.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #13 from ***@gmail.com ---
Did you have any luck with this?

I have a late 2009 imac and on installing kubuntu 18.04 the radeon driver fails
with a dark screen or defaults to vesa complaining - modprobe: ERROR: could
not insert 'radeon': Invalid argument if I use the nomodeset option from boot
(via refind).
I've reported this in bug 107324.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #14 from ***@gmail.com ---
I've attached a separate screen via the displayport, and the radeon driver
loads and I get the second monitor as a secondary screen, from which I can
access kscreen through the settings dialog and then set as the primary.
Throughout this time, the secondary display is working but is dark in
comparison to what I would expect, but the primary screen, the imac, is a black
screen except for tear type artefacts like barely visible equidistant lines
floating upwards.
I would guess that the edid is reported incorrectly, as the imac screen is
reported in the settings dialog as 'laptop'.
I'm going to try obtaining and setting an edid etc now.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #15 from ***@gmail.com ---
Created attachment 140762
--> https://bugs.freedesktop.org/attachment.cgi?id=140762&action=edit
xorg.0.log

this is with the external screen attached. I've attached another file of
xorg.0.log.old with no screen attached and a failed boot.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #16 from ***@gmail.com ---
Created attachment 140763
--> https://bugs.freedesktop.org/attachment.cgi?id=140763&action=edit
xorg.0.log.old

failed boot log

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

***@gmail.com changed:

What |Removed |Added
----------------------------------------------------------------------------
CC| |***@gmail.co
| |m

--- Comment #17 from ***@gmail.com ---
*** Bug 107324 has been marked as a duplicate of this bug. ***

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #18 from ***@gmail.com ---
I am currently running a rt compiled kernel for audio use at the latest patch
level, so 4.9.98, but I get the same problem on the generic installed kernel
that is 4.17 I think. I'll check now.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #19 from ***@gmail.com ---
the generic is 4.15.0-29-generic #31-Ubuntu SMP Tue Jul 17 15:39:52 UTC 2018
x86_64 x86_64 x86_64 GNU/Linux

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #20 from ***@gmail.com ---
looks like the edid is fried.

his is read-edid version 3.0.2. Prepare for some fun.
Attempting to use i2c interface
Only trying 6 as per your request.
256-byte EDID successfully retrieved from i2c bus 6
Looks like i2c was successful. Have a good day.
Checksum Correct

Section "Monitor"
Identifier "Color LCD"
ModelName "Color LCD"
VendorName "APP"
# Monitor Manufactured week 28 of 2009
# EDID version 1.4
# Digital Display
DisplaySize 600 340
Gamma 2.20
Option "DPMS" "true"

#Extension block found. Parsing...
extb[4]: 0x23 (0x20)
Hmm, you have data blocks, but not video ones... weird
Something strange happened. Please contact the author,

I'll try updating the apple firmware to see if that might help.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #21 from ***@gmail.com ---
Created attachment 140768
--> https://bugs.freedesktop.org/attachment.cgi?id=140768&action=edit
results.log from the ubuntu firmware checking tool

from https://wiki.ubuntu.com/FirmwareTestSuite/

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #22 from Michel DÀnzer <***@daenzer.net> ---
(In reply to jamesstewartmiller from comment #14)

Post by b***@freedesktop.org
I would guess that the edid is reported incorrectly, as the imac screen is
reported in the settings dialog as 'laptop'.

FWIW, sounds rather like the settings app just incorrectly assumes that only
laptops have eDP outputs.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #23 from ***@gmail.com ---
Thanks, I thought that the display size was incorrect, but I have since seen
how the size is calculated.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=98046

--- Comment #24 from James Cameron <***@laptop.org> ---
Thanks for asking, James. No, I've no progress to report since my previous
comments here. I'm still using a local kernel on the affected machine, and
haven't had time to resolve the outstanding questions I listed. Let me know if
you need any information.