lkml.org 
[lkml]   [2007]   [Jun]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
Subject"upping" a semaphore from interrupt context?
From
Hello,

I am writing a USB driver for some custom hardware, and I need to
synchronize between the user-space and the USB subsystem. Can I
create a semaphore and "down" it in the reader then "up" it in the
completion handler?

I know the completion handler runs in interrupt context so you are not
allowed to acquire any semaphores: but can you release them? Will the
waiting tasks wake up after the handler and its caller returned - IOW
will the waking up task run in interrupt context as well?

This is with Linux 2.4 (if it makes a difference).

Thanks,
florin

--
Bruce Schneier expects the Spanish Inquisition.
http://geekz.co.uk/schneierfacts/fact/163
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2007-06-22 19:41    [W:0.039 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site