Re: request_firmware() hotplug interface, third round.

[David Gibson <david@gibson.dropbear.id.au>]

On Sat, May 17, 2003 at 12:30:37PM +0200, Manuel Estrada Sainz wrote:
> On Sat, May 17, 2003 at 07:07:05PM +1000, David Gibson wrote:
> > On Sat, May 17, 2003 at 10:46:12AM +0200, Manuel Estrada Sainz wrote:
> > > On Sat, May 17, 2003 at 02:44:59PM +1000, David Gibson wrote:
> > > > On Fri, May 16, 2003 at 05:03:38PM -0700, Greg Kroah-Hartman wrote:
> > > > > On Sat, May 17, 2003 at 01:55:15AM +0200, Oliver Neukum wrote:
> > > > > > 
> [snip]
> > >  But in case you are doing things by hand, how about:
> > >  
> > > 	$ echo cancel > .../loading
> > > 
> > > 	or if you want to keep the content numeric:
> > > 
> > > 	$ echo -1 > .../loading
> > > 
> > >  This will also allow the regular script to just cancel the load in case
> > >  of error, like if the firmware image is not available or a read error
> > >  happened while reading it.
> > > 
> > >  I'll implement that and the other stuff that came out of Oliver's
> > >  comments later today and post the new code.
> > >  
> > > > Better to catch the close, check the length, then return the firmware
> > > > or throw the junk image away as appropriate.
> > > 
> > >  If 'loading' stays the above should fix your timeout issue, and if it
> > >  goes, yes, that is probably the way to go.
> > 
> > How about combining these two ideas: instead of "loading" and "data"
> > we have "size" and "data".  First you write the size, then the data -
> > the driver accepts it once it gets the expected number of bytes.
> > Writing a new size throws away any partial image that's there, and
> > restarts the upload.  Writing 0 cancels the upload entirely, and the
> > driver will presumably fail to initialize (or maybe use a default
> > image if it has one).
> 
>  I just thought this over. This makes more requirements for the userspace
>  scripts, they will need some way to get the size of the image: stat, or
>  ls and some crude regex.
> 
>  And we can have the same effect with loading/data:
> 
>  echo 1 > .../loading:
>  	Will start a load, discarding any previous partial load.
>  echo 0 > .../loading:
>  	Will conclude the load and handle the data to the driver code.
>  echo -1 > .../loading:
> 	Will conclude the load with an error and the driver won't get
> 	any firmware, failing or using firmware in some flash if
> 	available.
> 
>  This way, the script also won't have to check the value of 'loading'.
> 
>  How does that sound?

Hrm... it still seems a bit icky to me, but I'm not really sure why.
I think it would be a bit better if you called it "control" or
something instead of "loading".  "loading" seems to imply a boolean,
which this isn't anymore.

-- 
David Gibson			| For every complex problem there is a
david@gibson.dropbear.id.au	| solution which is simple, neat and
				| wrong.
http://www.ozlabs.org/people/dgibson