Re: Re: [PATCH] filling in ACPI method access via sysfs

[Alex Williamson <alex.williamson-VXdhtT5mjnY@public.gmane.org>]

On Tue, 2004-04-13 at 16:15, Paul Ionescu wrote:
> Hi Alex,
> 
> I tried to play with your new patch. I am able now to run arbitrary
> parameterless methods. I have some problems accessing the methods
> requiring parameters, or giving results.
> 
> I did an "echo 1 > /sys/.../DOCK/_DCK " but nothing happened, and I have
> tried also to cat it but I got "cat: Read error: No such device"
> 
> And I did an "cat /sys/.../_STA" and I receive 
> cat: Read error: No such device
> Do I miss something ?
> 

   Yeah, the latest iteration only supports read/write to the files, I
removed support for the show/store ops.  So, you need a program/script
that open()s the file, write()s arguments (if any), read()s the results,
and close()s the file.  Thanks,

	Alex

> 
> On Sun, 2004-04-11 at 16:29, Alex Williamson wrote: 
> >> 
> >> It seems unintuitive that you have to read the file for the method to
> >> take effect.  How about having the write function invoke the method and
> >> (if there is a result) store it for later read-back via the read function?
> >> It should be discarded on close, of course.  A read() on a file with
> >> no stored result should invoke the ACPI method (on the assumption this
> >> is a parameter-less method) and return the result directly.  Closing a
> >> file should discard any result from the method.
> >
> >  How's this?  It behaves the way you described, but might be doing
> > some questionable things with the buffer to get there.  Is there a
> > better place to store the return data than back into the buf passed to
> > write() (aka file->private_data)?  Without adding callbacks to
> > open/close, I'm not sure how else we can dispose of the results on
> > close.  Thanks,
> >
> >	Alex
-- 
Alex Williamson                             HP Linux & Open Source Lab



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