* ath9k prevents CPU from entering C4 state (kernel 2.6.37 regression) @ 2011-01-22 20:38 Richard Schütz 2011-01-22 22:52 ` Christian Lamparter 0 siblings, 1 reply; 3+ messages in thread From: Richard Schütz @ 2011-01-22 20:38 UTC (permalink / raw) To: linux-wireless I noticed that from kernel 2.6.37 on (i've tested 2.6.38-rc2, too) ath9k prevents my CPU (Intel Atom N450) from entering the C4 power state. It only goes down to C2 (there's no C3) instead. In 2.6.36(.3) everything is still fine. The CPU will only go down to C4 with 2.6.37 when the wireless interface is brought down. used wireless device: 05:00.0 Network controller: Atheros Communications Inc. AR9285 Wireless Network Adapter (PCI-Express) (rev 01) -- Regards, Richard Schütz ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: ath9k prevents CPU from entering C4 state (kernel 2.6.37 regression) 2011-01-22 20:38 ath9k prevents CPU from entering C4 state (kernel 2.6.37 regression) Richard Schütz @ 2011-01-22 22:52 ` Christian Lamparter 2011-01-22 23:49 ` Thomas Bächler 0 siblings, 1 reply; 3+ messages in thread From: Christian Lamparter @ 2011-01-22 22:52 UTC (permalink / raw) To: Richard Schütz; +Cc: linux-wireless On Saturday 22 January 2011 21:38:47 Richard Schütz wrote: > I noticed that from kernel 2.6.37 on (i've tested 2.6.38-rc2, too) ath9k > prevents my CPU (Intel Atom N450) from entering the C4 power state. It > only goes down to C2 (there's no C3) instead. In 2.6.36(.3) everything > is still fine. The CPU will only go down to C4 with 2.6.37 when the > wireless interface is brought down. "ath9k: Fix a DMA latency issue for Intel Pinetrail platforms." http://www.spinics.net/lists/linux-wireless/msg58264.html the pm_qos value will be configurable with 2.6.38: "ath9k: Make PM-QOS value as user configurable" http://www.spinics.net/lists/linux-wireless/msg61259.html "This will help our customers to configure the pm-qos value according to the effect in throughput due to the DMA latency problem which was observed in Intel Pinetrail platforms." ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: ath9k prevents CPU from entering C4 state (kernel 2.6.37 regression) 2011-01-22 22:52 ` Christian Lamparter @ 2011-01-22 23:49 ` Thomas Bächler 0 siblings, 0 replies; 3+ messages in thread From: Thomas Bächler @ 2011-01-22 23:49 UTC (permalink / raw) To: Christian Lamparter; +Cc: Richard Schütz, linux-wireless [-- Attachment #1: Type: text/plain, Size: 715 bytes --] Am 22.01.2011 23:52, schrieb Christian Lamparter: > On Saturday 22 January 2011 21:38:47 Richard Schütz wrote: >> I noticed that from kernel 2.6.37 on (i've tested 2.6.38-rc2, too) ath9k >> prevents my CPU (Intel Atom N450) from entering the C4 power state. It >> only goes down to C2 (there's no C3) instead. In 2.6.36(.3) everything >> is still fine. The CPU will only go down to C4 with 2.6.37 when the >> wireless interface is brought down. > > "ath9k: Fix a DMA latency issue for Intel Pinetrail platforms." > http://www.spinics.net/lists/linux-wireless/msg58264.html I experience the same problem, and I do not have a Pinetrail. I run Intel Core i5-520M (Arrandale) with an AR9280 Rev 2. [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 262 bytes --] ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2011-01-22 23:57 UTC | newest] Thread overview: 3+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2011-01-22 20:38 ath9k prevents CPU from entering C4 state (kernel 2.6.37 regression) Richard Schütz 2011-01-22 22:52 ` Christian Lamparter 2011-01-22 23:49 ` Thomas Bächler
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).