lkml.org 
[lkml]   [2010]   [Apr]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: [linux-pm] [PATCH 2/9] PM: suspend_block: Add driver to access suspend blockers from user-space
Date
On Tuesday 27 April 2010, Alan Stern wrote:
> On Mon, 26 Apr 2010, Arve Hjønnevåg wrote:
>
> > > If you insist on using ioctl for init, you should use the standard
> > > convention for passing variable-length data. The userspace program
> > > sets up a fixed-size buffer containing a pointer to the name and the
> > > name's length, and it passes the buffer's address as the ioctl
> > > argument.
> >
> > Are you sure that is the standard? I searched for ioctls with NAME in
> > their name and only found one that passed the name that way. The rest
> > used fixed length string buffers, or passed the buffersize to _IOC
> > like I do. For instance, input.h has ioctls to read string and
> > bitmasks where user space specify the buffer size as an argument to
> > the ioctl macro. These pass data from the kernel to user space, but I
> > don't passing a string length is any worse than passing a buffer size.
>
> You're right. Okay, I withdraw my objection.

In the meantime, though, I thought that the suspend blocker might be created
by _open() if we found a way to automatically choose a name for it. That'd be
kind of logical, since it's later destroyed by _release().

So, what about using the name of the process that opened the special device
file (or that name with'0' appended, or generally with a number appended) as
the suspend blocker name?

Rafael
--
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/

\
 
 \ /
  Last update: 2010-04-28 00:05    [from the cache]
©2003-2011 Jasper Spaans