[PATCH 0/3] AR6k: don't waste so much time in shutdown

Werner Almesberger werner at openmoko.org
Mon Jan 19 20:48:11 CET 2009

The following small patches remove unnecessary and large delays from
the shutdown path of the AR6k driver. This speeds up suspend, module
removal, unbinding, rfkill, and system shutdown.

For comparison, in one of my test systems (*) the time between
initiating a system-wide suspend and the CPU suspending used to be
between 1.8 and 3.5 seconds [1], depending on whether WLAN was
actively being used.

With these changes, the time is reduced to about 0.5 seconds. [2]

If disabling AR6k driver removal with
echo 1 >/sys/module/s3cmci/parameters/persist
the suspend time drops to 0.25 seconds. [3]

(*) The test system is a GTA02v5 running the latest andy-tracking
    with gta02-moredrivers-defconfig. Since the microSD slot of
    this device is defectice, CONFIG_MFD_GLAMO_MCI has been
    disabled. The experiments therefore don't include any suspend
    delays added by glamo-mci and the MMC stack.

[1] http://people.openmoko.org/werner/suspend-original.png
[2] http://people.openmoko.org/werner/suspend-tidied.png
[3] http://people.openmoko.org/werner/suspend-persist.png

- Werner

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