[maemo-developers] WLAN Horrible Roaming Performance (N800, OS2008), Software or Hardware Problem ?

[From: Kalle Valo]

"ext Siarhei Siamashka" <siarhei.siamashka at gmail.com> writes:

> A while ago I looked for various kernel docs to see what's happening in the
> wlan driver and what can be done to reduce cpu load. My impression was that
> tasklet can be only preempted by hardware interrupts, so it is impossible to
> sleep in it and give cpu resources to userland applications. If that is true,
> no matter if n800 driver looks nicer, it must end up busylooping too.

Nope, on N800 cx3110x and omap2_mcspi do not busyloop during the DMA
transfer. They use workqueues to allow sleeping, and completions for
signalling.

To be exact both cx3110x and omap2_mcspi do busyloop on certain
occasions (waking up the chip etc.), but they do not busyloop during
DMA.

-- 
Kalle Valo