FS#52452 - [linux] lspci and every Qt 5 app and wake up dGPU on launch
Attached to Project:
Arch Linux
Opened by Eugene Shalygin (eshalygin) - Monday, 09 January 2017, 08:51 GMT
Last edited by Tobias Powalowski (tpowa) - Friday, 24 March 2017, 08:08 GMT
Opened by Eugene Shalygin (eshalygin) - Monday, 09 January 2017, 08:51 GMT
Last edited by Tobias Powalowski (tpowa) - Friday, 24 March 2017, 08:08 GMT
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Details
Description:
After a recent update when I launch any Qt 5 app, it wakes up discrete GPU, beginning with Plasma XSession startup programs. Additional info: $ lspci 00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor DRAM Controller (rev 06) 00:01.0 PCI bridge: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor PCI Express x16 Controller (rev 06) 00:02.0 VGA compatible controller: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller (rev 06) 00:03.0 Audio device: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller (rev 06) 00:14.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI (rev 05) 00:16.0 Communication controller: Intel Corporation 8 Series/C220 Series Chipset Family MEI Controller #1 (rev 04) 00:1a.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #2 (rev 05) 00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 05) 00:1c.0 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1 (rev d5) 00:1c.1 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #2 (rev d5) 00:1c.2 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #3 (rev d5) 00:1c.3 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #4 (rev d5) 00:1d.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #1 (rev 05) 00:1f.0 ISA bridge: Intel Corporation HM87 Express LPC Controller (rev 05) 00:1f.2 SATA controller: Intel Corporation 8 Series/C220 Series Chipset Family 6-port SATA Controller 1 [AHCI mode] (rev 05) 00:1f.3 SMBus: Intel Corporation 8 Series/C220 Series Chipset Family SMBus Controller (rev 05) 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Neptune XT [Radeon HD 8970M] 03:00.0 PCI bridge: Texas Instruments XIO2213A/B/XIO2221 PCI Express to PCI Bridge [Cheetah Express] (rev 01) 04:00.0 FireWire (IEEE 1394): Texas Instruments XIO2213A/B/XIO2221 IEEE-1394b OHCI Controller [Cheetah Express] (rev 01) 05:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTL8411 PCI Express Card Reader (rev 01) 05:00.2 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0a) 06:00.0 Network controller: Intel Corporation Wireless 7260 (rev bb) Wow, lspci does this too. $ uname -a Linux kitty 4.8.13-1-ARCH #1 SMP PREEMPT Fri Dec 9 07:24:34 CET 2016 x86_64 GNU/Linux Steps to reproduce: launch any Qt 5 app (assistant) or lspci |
This task depends upon
I'll try to explain. I have a laptop with two GPU cards (see lspci output above). The AMD one is discrete (dGPU). Normally it is not used and powered off. However, after a recent update launching some software wakes the card up. It switches on, works for a few seconds, and then turns off again. This sequence is similar to results of launching, for instance, glxinfo with DRI_PRIME environment variable set tot 1. dmesg log contains similar entries for these events. The list of software that wake up dGPU I found so far includes all Qt5, lspci, and firefox. Was it clear now?
$ strace lspci
...
open("/sys/bus/pci/devices/0000:01:00.0/config", O_RDONLY) = 3
pread64(3,