Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Description of problem:
I need to manually set kernel cmdline paramaters 'pcie_aspm=force i915.i915_enable_rc6=1' to decrease heating of my laptop from 55 to 45 °C. Also increase battery time.
Tested on 2 laptops:
ThinkPad T420s
--------------
# lspci -s 00:02.0 -v
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])
Subsystem: Lenovo Device 21d2
Flags: bus master, fast devsel, latency 0, IRQ 31
Memory at f0000000 (64-bit, non-prefetchable) [size=4M]
Memory at e0000000 (64-bit, prefetchable) [size=256M]
I/O ports at 4000 [size=64]
Expansion ROM at <unassigned> [disabled]
Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
Capabilities: [d0] Power Management version 2
Capabilities: [a4] PCI Advanced Features
Kernel driver in use: i915
Kernel modules: i915
# uname -a
Linux localhost.localdomain 2.6.32-280.el6.x86_64 #1 SMP Mon Jun 18 17:28:46 EDT 2012 x86_64 x86_64 x86_64 GNU/Linux
HP Mini 5103 (WT211ES#ARL)
--------------------------
# lspci -s 00:02.0 -v
00:02.0 VGA compatible controller: Intel Corporation N10 Family Integrated Graphics Controller (rev 02) (prog-if 00 [VGA controller])
Subsystem: Hewlett-Packard Company Device 1608
Flags: bus master, fast devsel, latency 0, IRQ 26
Memory at 90480000 (32-bit, non-prefetchable) [size=512K]
I/O ports at 30a0 [size=8]
Memory at 80000000 (32-bit, prefetchable) [size=256M]
Memory at 90300000 (32-bit, non-prefetchable) [size=1M]
Expansion ROM at <unassigned> [disabled]
Capabilities: [90] MSI: Enable+ Count=1/1 Maskable- 64bit-
Capabilities: [d0] Power Management version 2
Kernel driver in use: i915
Kernel modules: i915
# uname -a
Linux localhost.localdomain 2.6.32-220.17.1.el6.x86_64 #1 SMP Tue May 15 17:16:46 CDT 2012 x86_64 x86_64 x86_64 GNU/Linux
Version-Release number of selected component (if applicable):
kernel-2.6.32-220.17.1.el6.x86_64
kernel-2.6.32-280.el6.x86_64
How reproducible:
100%
Steps to Reproduce:
1. Try default RHEL installation on laptop that can use i915 kernel driver
2. Check CPU temperature and battery time.
3. Add at boot 'pcie_aspm=force i915.i915_enable_rc6=1'
4. Check CPU temperature and battery time.
Actual results:
Default RHEL cpu temperature is 10 degrees higher. Battery time is shorter.
Expected results:
Default RHEL cpu temperature is NOT 10 degrees higher. Battery time is NOT shorter.
Additional info:
I can confirm that battery life is horrible on the Lenovo x220 with RHEL 6.3, 3 to 4 hours. With Fedora 17 it's close to 10.
I tried the kernel args:
pcie_aspm=force i915.i915_enable_rc6=1 i915.lvds_downclock=1 i915.i915_enable_fbc=1
as described in this article: http://www.williambrownstreet.net/blog/?p=387
and saw significant improvement--in line with Fedora. Bonus points too because the bottom of the unit is much cooler and the fan barely runs, making it less noisy.
I had 62'C temperature after installing RHEL6.3 workstation on my X220, and after applying the kernel args from comment #1 the temperature dropped to 49'C.
(In reply to comment #3)
> I'm pretty reluctant to change the ASPM policy in 6, given the potential for
> breaking hardware.
And what about 'i915.i915_enable_rc6=1' - is that possible?
If it is not, can we add this into 'tuned' package?