Bug 96464

Summary:

Screen update issue (drm/i915/fbc: enable FBC by default on HSW and BDW)

Product:

DRI

Reporter:

Steven Honeyman <stevenhoneyman>

Component:

DRM/Intel

Assignee:

Paulo Zanoni <przanoni>

Status:

CLOSED FIXED

QA Contact:

Intel GFX Bugs mailing list <intel-gfx-bugs>

Severity:

normal

Priority:

medium

CC:

intel-gfx-bugs, przanoni

Version:

unspecified

Hardware:

x86-64 (AMD64)

OS:

Linux (All)

Whiteboard:

i915 platform:

HSW

i915 features:

display/FBC

Attachments:

Description	Flags
dmesg output (fifo\|under\|i915\|intel\|drm)	none
Xorg.0.log (fbc enabled)	none

Description Steven Honeyman 2016-06-09 18:33:16 UTC

Created attachment 124423 [details]
dmesg output (fifo|under|i915|intel|drm)

Following advice from Paulo Zanoni (https://lists.freedesktop.org/archives/intel-gfx/2016-June/098125.html), I'm submitting this here along with the requested logs.

To summarise:
My screen update speed goes down once or twice per second in a Haswell Dell E6540, with FBC enabled. It's incredibly noticable when typing and text appears in chunks. In kernel 4.6.2 moving the mouse while holding a key would hide the problem, but this does not apply to 4.7.0-rc2.

I'm using Arch Linux as a 'base' distro, but many packages that have compile time options I'm building myself. Luckily Xorg is not one of them, that's stock:

$ pacman -Ss xorg|grep -i installed
extra/xf86-input-evdev 2.10.3-1 (xorg-drivers xorg) [installed]
extra/xf86-input-synaptics 1.8.3-2 (xorg-drivers xorg) [installed]
extra/xf86-video-intel 1:2.99.917+654+ga508b11-1 (xorg-drivers xorg) [installed]
extra/xorg-bdftopcf 1.0.5-1 (xorg xorg-apps) [installed]
extra/xorg-font-util 1.3.1-1 (xorg-fonts xorg) [installed]
extra/xorg-font-utils 7.6-4 [installed]
extra/xorg-fonts-100dpi 1.0.3-2 (xorg) [installed]
extra/xorg-fonts-alias 1.0.3-1 [installed]
extra/xorg-fonts-cyrillic 1.0.3-1 [installed]
extra/xorg-fonts-encodings 1.0.4-4 (xorg-fonts xorg) [installed]
extra/xorg-fonts-misc 1.0.3-4 [installed]
extra/xorg-luit 1.1.1-2 (xorg xorg-apps) [installed]
extra/xorg-mkfontdir 1.0.7-2 (xorg xorg-apps) [installed]
extra/xorg-mkfontscale 1.1.2-1 (xorg-apps xorg) [installed]
extra/xorg-server 1.18.3-2 (xorg) [installed]
extra/xorg-server-common 1.18.3-2 (xorg) [installed]
extra/xorg-server-xvfb 1.18.3-2 (xorg) [installed]
extra/xorg-setxkbmap 1.3.1-1 (xorg-apps xorg) [installed]
extra/xorg-xauth 1.0.9-1 (xorg-apps xorg) [installed]
extra/xorg-xbacklight 1.2.1-1 (xorg-apps xorg) [installed]
extra/xorg-xdpyinfo 1.3.2-1 (xorg-apps xorg) [installed]
extra/xorg-xev 1.2.2-1 (xorg-apps xorg) [installed]
extra/xorg-xfontsel 1.0.5-1 [installed]
extra/xorg-xinit 1.3.4-4 [installed]
extra/xorg-xinput 1.6.2-1 (xorg-apps xorg) [installed]
extra/xorg-xkbcomp 1.3.1-1 (xorg-apps xorg) [installed]
extra/xorg-xmag 1.0.6-1 [installed]
extra/xorg-xmessage 1.0.4-2 [installed]
extra/xorg-xmodmap 1.0.9-1 (xorg-apps xorg) [installed]
extra/xorg-xprop 1.2.2-1 (xorg-apps xorg) [installed]
extra/xorg-xrandr 1.5.0-1 (xorg-apps xorg) [installed]
extra/xorg-xrdb 1.1.0-2 (xorg-apps xorg) [installed]
extra/xorg-xset 1.2.3-1 (xorg-apps xorg) [installed]
extra/xorg-xwininfo 1.1.3-1 (xorg-apps xorg) [installed]

I've attached the output of dmesg|grep -Ei '(fifo|under|i915|intel|drm)'
I'll follow up with the Xorg.0.log (only seem to be able to attach 1 file)

Comment 1 Steven Honeyman 2016-06-09 18:34:06 UTC

Created attachment 124424 [details]
Xorg.0.log (fbc enabled)

Comment 2 Paulo Zanoni 2016-06-09 19:05:39 UTC

Does the problem still happen if you apply these patches:

https://patchwork.freedesktop.org/patch/79567/
https://patchwork.freedesktop.org/patch/80857/
https://patchwork.freedesktop.org/patch/92634/

Thanks,
Paulo

Comment 3 Steven Honeyman 2016-06-09 19:26:03 UTC

(In reply to Paulo Zanoni from comment #2)
> Does the problem still happen if you apply these patches:
> 
> https://patchwork.freedesktop.org/patch/79567/
> https://patchwork.freedesktop.org/patch/80857/
> https://patchwork.freedesktop.org/patch/92634/
> 
> Thanks,
> Paulo

All looks OK so far with those 3 patches applied.

# cat /sys/kernel/debug/dri/0/i915_fbc_status
FBC disabled: FBC enabled (active or scheduled)
Compressing: yes


Thanks,
Steven

Comment 4 Paulo Zanoni 2016-06-20 21:27:45 UTC

(In reply to Steven Honeyman from comment #3)
> (In reply to Paulo Zanoni from comment #2)
> > Does the problem still happen if you apply these patches:
> > 
> > https://patchwork.freedesktop.org/patch/79567/
> > https://patchwork.freedesktop.org/patch/80857/
> > https://patchwork.freedesktop.org/patch/92634/
> > 
> > Thanks,
> > Paulo
> 
> All looks OK so far with those 3 patches applied.

All these patches were merged, and, in addition, FBC was also disabled by default on HSW, so we can close the bug. You can still use i915.enable_fbc=1 on your machine if you want.

We'll try again to enable FBC on HSW later, when all the bug reporters confirm the current tree works for them.

Also, see #96461.

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