User: Password:
|
|
Subscribe / Log in / New account

Drivers as documentation

Drivers as documentation

Posted Nov 25, 2011 6:02 UTC (Fri) by jzbiciak (subscriber, #5246)
In reply to: Drivers as documentation by juliank
Parent article: Drivers as documentation

Ok, this is somewhat offtopic, but it piqued my curiosity...

We also have some strange things, like having to add an udelay() somewhere because the device otherwise locks up, and we don't know why

Memory ordering issue, and a barrier of some sort is required? Does the lockup happen on the same chip as the original usleep-less Android implementation?


(Log in to post comments)

Drivers as documentation

Posted Nov 25, 2011 14:44 UTC (Fri) by juliank (subscriber, #45896) [Link]

> Memory ordering issue, and a barrier of some sort is required?
> Does the lockup happen on the same chip as the original
> usleep-less Android implementation?

Seems I misremembered. It does not lock up, it just sends
incomplete messages. I added an udelay(100) in commit
de839b8f06bc5dd3f5037c4409a720cbb9bf21c3 [1] which seems to
prevent that.

[1] https://git.kernel.org/?p=linux/kernel/git/torvalds/linux...


Copyright © 2017, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds