Bug 753367 - i915 causes a lot of interrupts even when idle
Summary: i915 causes a lot of interrupts even when idle
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Fedora
Classification: Fedora
Component: xorg-x11-drv-intel
Version: 16
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Adam Jackson
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2011-11-12 01:27 UTC by Martin Weinelt
Modified: 2013-02-13 08:02 UTC (History)
7 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2013-02-13 08:02:34 UTC
Type: ---


Attachments (Terms of Use)
Idle Laptop with high number of interrupts on i915 (71.77 KB, image/png)
2011-11-12 01:27 UTC, Martin Weinelt
no flags Details

Description Martin Weinelt 2011-11-12 01:27:10 UTC
Created attachment 533199 [details]
Idle Laptop with high number of interrupts on i915

Description of problem:
The i915 module constantly produces quite alot of interrupts (40-70), even when my laptop is idle. This is quite a power leak (> 1W).


Version-Release number of selected component (if applicable):
kernel 3.1.0-7.fc16

How reproducible:
Always

Steps to Reproduce:
1. see powertop
  
Actual results:
http://img7.imagebanana.com/img/5xas14v4/Bildschirmfotoam20111112022241.png

Expected results:
On Ubuntu Oneiric (Kernel 3.0.x) i915 goes down to 0,0 interrupts with the same hardware.

Additional info:

00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 02) (prog-if 00 [VGA controller])
	Subsystem: Lenovo Device 215a
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
	Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 0
	Interrupt: pin A routed to IRQ 41
	Region 0: Memory at f2000000 (64-bit, non-prefetchable) [size=4M]
	Region 2: Memory at d0000000 (64-bit, prefetchable) [size=256M]
	Region 4: I/O ports at 1800 [size=8]
	Expansion ROM at <unassigned> [disabled]
	Capabilities: <access denied>
	Kernel driver in use: i915
	Kernel modules: i915

Comment 1 Adam Jackson 2011-11-14 16:17:40 UTC
Do you experience this when booting to runlevel 3 (ie, without gnome active)?

Do you experience this if booting with i915.i915_enable_fbc=0 on the kernel command line?

Comment 2 Martin Weinelt 2011-11-14 16:28:20 UTC
> Do you experience this when booting to runlevel 3 (ie, without gnome active)?
Everything seems fine in init 3


> Do you experience this if booting with i915.i915_enable_fbc=0 on the kernel
command line?
Don't know if I did it right but here's how I did what you asked:
1. Pressed 'e' in grub
2. Appended "i915.i915_enable_fbc=0" to the line beginning with "linux [...]"
3. Pressed F10 to boot

=> Still 40-60 Interrupts when idle

Comment 3 Adam Jackson 2011-11-14 18:06:23 UTC
(In reply to comment #2)
> > Do you experience this when booting to runlevel 3 (ie, without gnome active)?
> Everything seems fine in init 3

Then you're almost certainly seeing the sync-to-vblank interrupt.  Which means you're drawing 40-60 frames a second for some reason.

If you ssh into the machine while it's idle (fresh login, no apps running) and run powertop, do you see the same interrupt load?  If so this is probably a bug in the base gnome session causing excessive redraws.  If not, you're probably simply seeing the interrupt load from running powertop itself.

Comment 4 Martin Weinelt 2011-11-14 18:38:53 UTC
The number of interrupts I see via ssh is significantly lower than inside the gnome session itself.

Where do we go from here?

Comment 5 Martin Weinelt 2011-11-14 18:40:00 UTC
"significantly lower" means ~0-15.

Comment 6 Fedora End Of Life 2013-01-16 09:58:36 UTC
This message is a reminder that Fedora 16 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 16. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
'version' of '16'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version prior to Fedora 16's end of life.

Bug Reporter: Thank you for reporting this issue and we are sorry that 
we may not be able to fix it before Fedora 16 is end of life. If you 
would still like to see this bug fixed and are able to reproduce it 
against a later version of Fedora, you are encouraged to click on 
"Clone This Bug" and open it against that version of Fedora.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

The process we are following is described here: 
http://fedoraproject.org/wiki/BugZappers/HouseKeeping

Comment 7 Fedora End Of Life 2013-02-13 08:02:37 UTC
Fedora 16 changed to end-of-life (EOL) status on 2013-02-12. Fedora 16 is 
no longer maintained, which means that it will not receive any further 
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of 
Fedora please feel free to reopen this bug against that version.

Thank you for reporting this bug and we are sorry it could not be fixed.


Note You need to log in before you can comment on or make changes to this bug.