Hi, I believe this has been fixed in 2.6.36 release, tracked by https://bugzilla.kernel.org/show_bug.cgi?id=16307 However this appeared again since 2.6.37, below is the powertop output: 112.1 wakeups/second, 0.2 GPU ops/second and 0.0 VFS ops/sec 0.7 ms/s 56.1 Interrupt [43] i915 0.9 ms/s 22.9 Interrupt [6] tasklet(softirq) 175.8 us/s 9.7 kWork ieee80211_iface_work 126.7 us/s 5.8 Timer tick_sched_timer 94.2 us/s 5.1 Timer hrtimer_wakeup PowerTOP version 1.97 beta 1 Kernel version Linux version 2.6.38-rc4 (kanru@anar) (gcc version 4.4.5 (Debian 4.4.5-10) ) #8 SMP Wed Feb 9 12:14:46 CST 2011 System name Acer Aspire 3810T V1.28 CPU information 2x Intel(R) Core(TM)2 Duo CPU U9400 @ 1.40GHz lspci output: 00:00.0 Host bridge: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub (rev 07) 00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07) 00:02.1 Display controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07) 00:1a.0 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 (rev 03) 00:1a.1 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 (rev 03) 00:1a.7 USB Controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 (rev 03) 00:1b.0 Audio device: Intel Corporation 82801I (ICH9 Family) HD Audio Controller (rev 03) 00:1c.0 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 (rev 03) 00:1c.2 PCI bridge: Intel Corporation 82801I (ICH9 Family) PCI Express Port 3 (rev 03) 00:1d.0 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 (rev 03) 00:1d.1 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 (rev 03) 00:1d.2 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 (rev 03) 00:1d.3 USB Controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #6 (rev 03) 00:1d.7 USB Controller: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 (rev 03) 00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev 93) 00:1f.0 ISA bridge: Intel Corporation ICH9M-E LPC Interface Controller (rev 03) 00:1f.2 SATA controller: Intel Corporation ICH9M/M-E SATA AHCI Controller (rev 03) 00:1f.3 SMBus: Intel Corporation 82801I (ICH9 Family) SMBus Controller (rev 03) 00:1f.6 Signal processing controller: Intel Corporation 82801I (ICH9 Family) Thermal Subsystem (rev 03) 01:00.0 Network controller: Intel Corporation WiFi Link 5100 02:00.0 Ethernet controller: Atheros Communications AR8131 Gigabit Ethernet (rev c0)
Are you absolutely sure it's not vblank... ;-) I put back the patch we reverted last time, but only for gen5+ (so as to exclude your system). Can you either grab drm-intel-next and run 'trace-cmd record -e i915:i915_reg_rw' or add a printk inside the interrupt handler and attach the output?
Created attachment 47002 [details] trace-cmd report Yes, I tested with the kernel 2.6.38-rc4 with drm-intel-next branch merged. It was single user mode, no X, cursor off. Powertop still shows average 55 interrupt/sec. trace-cmd report attached.
It's unvarying, a repeat of: <idle>-0 [000] 161.866936: i915_reg_rw: read reg=0x20a4, len=4, val=(0x40, 0x0) <idle>-0 [000] 161.866938: i915_reg_rw: read reg=0x70024, len=4, val=(0x80440204, 0x0) <idle>-0 [000] 161.866938: i915_reg_rw: write reg=0x70024, len=4, val=(0x80440204, 0x0) <idle>-0 [000] 161.866939: i915_reg_rw: read reg=0x71024, len=4, val=(0x400206, 0x0) <idle>-0 [000] 161.866940: i915_reg_rw: write reg=0x71024, len=4, val=(0x400206, 0x0) <idle>-0 [000] 161.866941: i915_reg_rw: write reg=0x20a4, len=4, val=(0x40, 0x0) <idle>-0 [000] 161.866942: i915_reg_rw: read reg=0x20a4, len=4, val=(0x0, 0x0) <idle>-0 [000] 161.866943: i915_reg_rw: read reg=0x70024, len=4, val=(0x440002, 0x0) <idle>-0 [000] 161.866943: i915_reg_rw: write reg=0x70024, len=4, val=(0x440002, 0x0) <idle>-0 [000] 161.866944: i915_reg_rw: read reg=0x71024, len=4, val=(0x400000, 0x0) <idle>-0 [000] 161.866945: i915_reg_rw: write reg=0x20a4, len=4, val=(0x0, 0x0) <idle>-0 [000] 161.866946: i915_reg_rw: read reg=0x20a4, len=4, val=(0x0, 0x0) <idle>-0 [000] 161.866947: i915_reg_rw: read reg=0x70024, len=4, val=(0x440000, 0x0) <idle>-0 [000] 161.866948: i915_reg_rw: read reg=0x71024, len=4, val=(0x400000, 0x0)
(In reply to comment #3) > It's unvarying, a repeat of: > > <idle>-0 [000] 161.866936: i915_reg_rw: read > reg=0x20a4, len=4, val=(0x40, 0x0) > <idle>-0 [000] 161.866938: i915_reg_rw: read Should it varying?
It shouldn't be there at all! I was just surmising the info, before thinking about the next step...
Is this still a problem on 2.6.38.y ?
I don't see this problem in my 2.6.38 kernel. Dunno which commit fixed this, they seem non related.
Alright, thanks for the update! I'm closing this as unreproducible. If it returns, just post a note.