On Thu, Apr 08, 2010 at 03:47:50PM +0100, Mark Brown wrote:
On Thu, Apr 08, 2010 at 11:31:23AM +0200, Sascha Hauer wrote:
Here are some bugfix patches for the imx-ssi driver. It should also fix the problems reported in FIQ mode.
Applied all three, thanks - the hrtimer stuff works an awful lot better than the vanilla timer stuff did. It's a shame I hadn't noticed that hrtimers did manage to give better resolution on i.MX when I looked into this previously.
It'd be good if you could look into the timer sync issue - doing something like deferring the timer by a proportion of a period if the period hasn't elapsed ought to cover it.
I'll look into it. I'm thinking of
- busywaiting if the current period hasn't elapsed (should rarely if ever the case since the fiq works reliable and the timer interrupt introduces additional delays. - calculate the next callback time based on the current offset.
If you haven't pushed the patches forward it would be good to delay the hrtimer patch a bit. I managed to shoot the system down while playing audio with a hackbench 10. This doesn't happen without the hrtimer patch. This may be related to the problem Valentin reported.
Sascha