From: "Luis R. Rodriguez" <mcgrof@gmail.com>
To: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: David Quan <David.Quan@atheros.com>,
Bob Copeland <me@bobcopeland.com>,
"Luis R. Rodriguez" <mcgrof@bombadil.infradead.org>,
Jussi Kivilinna <jussi.kivilinna@mbnet.fi>,
ath5k-devel@lists.ath5k.org, linux-wireless@vger.kernel.org,
linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [ath5k-devel] [PATCH v2] ath5k: disable ASPM
Date: Sun, 20 Jun 2010 22:53:32 -0700 [thread overview]
Message-ID: <AANLkTim8iZmm8pEERJUsrQWOiLSjPUfCN-TFFzZZQWx2@mail.gmail.com> (raw)
In-Reply-To: <1277032723.9555.12.camel@maxim-laptop>
On Sun, Jun 20, 2010 at 4:18 AM, Maxim Levitsky <maximlevitsky@gmail.com> wrote:
> On Sun, 2010-06-20 at 01:13 -0700, Luis R. Rodriguez wrote:
>> > commit ac5de416f822917b927958b21186a82141550da7
>> > Author: Maxim Levitsky <maximlevitsky@gmail.com>
>> > Date: Thu Jun 17 23:21:42 2010 +0300
>> >
>> > ath5k: disable ASPM
>>
>> You are not disabling ASPM, you are disabling L0s. ASPM can work with
>> L1, for example.
> This is left over from original patch.
Your latest patch still has all this old info, please adjust.
> with open coded code I was able to disable just L0s and get stable
> operation.
> Note however that with this patch which implies CONFIG_PCIEASPM, pci
> core disables both L0s and L1
You do not need CONFIG_PCIEASPM to use ASPM on Linux, that is another
thing I have been meaning to clarify upstream but haven't had time to
do so yet.
> (I still need to test and see if I need that patch at all. Maybe just
> enabling CONFIG_PCIEASPM is enough...)
You should be able to test ASPM by just enabling the driver.
>> > Atheros card on Acer Aspire One (AOA150, Atheros Communications Inc. AR5001
>> > Wireless Network Adapter [168c:001c] (rev 01)) doesn't work well with ASPM
>> > enabled. With ASPM ath5k will eventually stall on heavy traffic with often
>> > 'unsupported jumbo' warnings appearing. Disabling ASPM L0s in ath5k fixes
>> > these problems.
>> >
>> > Reproduced with pcie_aspm=force and by using 'nc < /dev/zero > /dev/null' at
>> > both ends (usually stalls within seconds).
>>
>> I *highly* discourage the use of pcie_aspm=force, in fact I'm inclined
>> to just remove this junk code from the kernel. What you should do to
>> test ASPM on a device is to use setpci on the config space. I have
>> documented how you can do this here:
>>
>> http://wireless.kernel.org/en/users/Documentation/ASPM
>>
>> Reason for discouraging this is when you use this you enable ASPM on
>> *all* root complexes and *all* devices which do support ASPM. If you
>> have another device which is capable of ASPM but has it disabled for
>> some reason you will run into other issues.
>>
>> I should also note that loading a module already has an effect on
>> devices for ASPM. An example today is ath9k's ath9k_hw_init() which
>> runs simply during module load, this has some ASPM related code which
>> for example disables the PLL for ASPM for AR9003. I don't recall
>> exactly what we do with ath5k but just giving you an idea. To truly
>> test ASPM well I recommend to do something similar as with this script
>> or you can just give it a shot.
>>
>> http://kernel.org/pub/linux/kernel/people/mcgrof/aspm/enable-aspm
>>
>> Not like I expect very different results but just wanted to clarify
>> the details on force aspm.
>>
>> Why are you disabling L0s for all devices though? Why not just for the
>> reported device? Granted, L0s won't save you much more power but
>> still, why remove it completely, your commit log does not address that
>> in any way. It only states you have issues with L0s on one chipset but
>> what the patch really implies is you are disabling L0s completely for
>> all ath5k chipsets.
>
> First of all there aren't many PCIE ath5k based devices.
Doesn't matter.
> Two of them are known to be broken.
Which ones?
> Also Jussi Kivilinna said that he found that in windows .inf file there
> are some instructions to enable L1 but not L0s.
For which chipsets?
> Note that I tested that again, and card works very stable.
Thanks for your work on this, I want to just check internally if there
is another way, that's all.
> I didn't see a single drop to 0 bytes/s. In fact throughput never drops
> below 1 Mb/s. (usually about 2.4 Mb/s, with rare drops for few seconds
> to ~1Mb/s)
Disabling L0s should not affect performance.
Luis
next prev parent reply other threads:[~2010-06-21 5:53 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-28 10:09 [PATCH] ath5k: disable ASPM Jussi Kivilinna
2010-05-28 16:19 ` [ath5k-devel] " Pavel Roskin
2010-05-28 18:25 ` Jussi Kivilinna
2010-05-28 20:27 ` Pavel Roskin
2010-05-31 1:06 ` Bruno Randolf
2010-06-01 20:43 ` Luis R. Rodriguez
2010-05-28 17:40 ` Luis R. Rodriguez
2010-05-28 18:20 ` Jussi Kivilinna
2010-06-17 20:33 ` Maxim Levitsky
2010-06-18 8:20 ` Jussi Kivilinna
2010-06-18 9:09 ` [ath5k-devel] " RHS Linux User
2010-06-18 10:15 ` Maxim Levitsky
2010-06-18 10:49 ` Jussi Kivilinna
2010-06-18 11:05 ` Maxim Levitsky
2010-06-18 13:59 ` Bob Copeland
2010-06-18 14:11 ` Maxim Levitsky
2010-06-19 7:49 ` [PATCH v2] " Maxim Levitsky
2010-06-19 12:38 ` Bob Copeland
2010-06-19 13:02 ` Maxim Levitsky
2010-06-19 15:32 ` [PATCH v3] " Maxim Levitsky
2010-07-26 20:13 ` [ath5k-devel] " Luis R. Rodriguez
2010-07-26 20:49 ` Maxim Levitsky
2010-07-26 21:06 ` Luis R. Rodriguez
2010-07-26 21:14 ` Matthew Garrett
2010-07-26 22:20 ` Luis R. Rodriguez
2010-07-26 22:24 ` Matthew Garrett
2010-07-26 22:29 ` Luis R. Rodriguez
2010-07-26 21:17 ` Maxim Levitsky
2010-07-26 21:25 ` Matthew Garrett
2010-07-26 22:15 ` Luis R. Rodriguez
2010-07-26 22:21 ` Matthew Garrett
2010-07-26 22:26 ` Luis R. Rodriguez
2010-07-26 22:29 ` Matthew Garrett
2010-07-26 22:31 ` Luis R. Rodriguez
2010-07-26 22:33 ` Matthew Garrett
2010-07-26 22:43 ` Luis R. Rodriguez
2010-07-26 22:50 ` Matthew Garrett
2010-07-27 9:35 ` Maxim Levitsky
2010-07-27 15:57 ` Luis R. Rodriguez
2010-07-28 23:48 ` Maxim Levitsky
2010-07-29 0:06 ` Luis R. Rodriguez
2010-07-26 22:13 ` Luis R. Rodriguez
2010-07-26 22:56 ` Luis R. Rodriguez
2010-06-20 8:13 ` [ath5k-devel] [PATCH v2] " Luis R. Rodriguez
2010-06-20 11:18 ` Maxim Levitsky
2010-06-20 18:04 ` Maxim Levitsky
2010-06-21 5:53 ` Luis R. Rodriguez [this message]
2010-06-21 20:01 ` Jussi Kivilinna
2010-06-21 20:16 ` Maxim Levitsky
2010-06-21 20:33 ` Jussi Kivilinna
2010-06-21 20:39 ` Luis R. Rodriguez
2010-06-22 16:31 ` Matthew Garrett
2010-06-22 16:48 ` Luis R. Rodriguez
2010-06-22 16:52 ` Matthew Garrett
2010-06-22 17:17 ` Luis R. Rodriguez
2010-06-22 17:25 ` Matthew Garrett
2010-06-22 17:40 ` Luis R. Rodriguez
2010-06-22 17:50 ` Matthew Garrett
2010-06-22 18:28 ` Luis R. Rodriguez
2010-06-22 18:44 ` Matthew Garrett
2010-06-22 19:13 ` Luis R. Rodriguez
2010-06-22 19:31 ` Johannes Stezenbach
2010-06-22 19:37 ` Luis R. Rodriguez
2010-06-22 19:38 ` Luis R. Rodriguez
2010-06-23 14:39 ` Johannes Stezenbach
2010-06-23 16:28 ` Luis R. Rodriguez
2010-06-23 19:07 ` Johannes Stezenbach
2010-06-23 19:23 ` Johannes Stezenbach
2010-06-21 20:37 ` Luis R. Rodriguez
2010-06-21 23:55 ` Maxim Levitsky
2010-07-26 16:34 ` [PATCH] " Maxim Levitsky
2010-07-26 18:37 ` John W. Linville
2010-07-26 18:41 ` [ath5k-devel] " Luis R. Rodriguez
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