From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Lutomirski Subject: Re: [ACPI] Re: [PATCH] filling in ACPI method access via sysfs namespace Date: Sun, 11 Apr 2004 21:13:59 -0700 Sender: linux-kernel-owner@vger.kernel.org Message-ID: <407A1787.5060508@myrealbox.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: To: Alex Williamson Cc: Matthew Wilcox , John Belmonte , acpi-devel@lists.sourceforge.net, linux-kernel List-Id: linux-acpi@vger.kernel.org Alex Williamson wrote: > On Sun, 2004-04-11 at 16:29, Matthew Wilcox 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, Is there any reason this shouldn't be an ioctl? --Andy