Hello Greg,

Am Mittwoch, den 12.09.2007, 04:39 -0700 schrieb Greg KH:
quoted text
> > > Do an lseek back to 0 and then re-read, you will get called in your
> > > driver again.
> > 
> > No thats not true. I thought this too, but if I make a:
> > 
> > seek (fd, 0L, SEEK_SET);
> > 
> > in Userspace, there is no retrigger in the sysFS, my driver is *not*
> > called again. So I made a own sysfs_seek function, which does retrigger
> > the driver ...
> 
> Hm, are you sure?  Otherwise the poll() stuff would not work at all.

Yes.
Sysfs uses generic_file_llseek (). And in sysfs_read_file ()
buffer->needs_read_fill must be 1, to reread from the driver.
generic_file_llseek () doesnt change this variable.

Best regards
Heiko
-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

-
unsubscribe notice
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/