On Wed, Sep 12, 2007 at 07:32:07AM +0200, Robert Schwebel wrote: > On Tue, Sep 11, 2007 at 11:43:17AM +0200, Heiko Schocher wrote: > > I have developed a device driver and use the sysFS to export some > > registers to userspace. > > Uuuh, uggly. Don't do that. Device drivers are there to abstract things, > not to play around with registers from userspace. > > > I opened the sysFS File for one register and did some reads from this > > File, but I alwas becoming the same value from the register, whats not > > OK, because they are changing. So I found out that the sysFS caches > > the reads ... :-( > > Yes, it does. What you can do is close()ing the file handle between > accesses, which makes it work but is slow.
Do an lseek back to 0 and then re-read, you will get called in your driver again. Not that this is a good thing to do for this kind of thing, as others have already said. thanks, greg k-h - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
