[alsa-devel] [PATCH 3/5] asihpi: Remove HPI4000

[Takashi Iwai]

At Fri, 14 Mar 2008 09:46:02 +1300,
Eliot Blennerhassett wrote:
> 
> > OK.  BTW, what if the newer firmware is loaded onto the old driver?
> 
> Within limits (how far apart driver and firmware are) this will work. 
> Mostly we are adding functions to the firmware, so old driver will work 
> with new firmware but a new driver won't work with old firmware.
> Sometimes old functions are deprecated, but we don't remove them 
> straight away.

As long as the backward-compatibility is kept, I think it's fine to
use the same name.  What I'm concerned is rather the regression by the
firmware package update.

So, I suppose the driver won't crash even if you have only the old
firmware?

> In the windows world our "driver" install includes driver, firmware, 
> userspace dll, python bindings, and mixer application all matching.

Not that on Linux, obviously :)
Of course, distros should provide the consistent packages, though.

> > Would it be safer to rename the firmware file for each incompatible
> > version?  If yes, we can change the asihpi driver code together with
> > the firmware renames to couple tightly.
> 
> The firmware images contain the HPI version encoded in the header.  I 
> will at least log a warning that the driver and firmware version do not 
> match.

That'll be good.

> I guess its possible to use versioned file names. Did you have something 
> in mind? Currently the filename is generated from an adapter ID:
> 
> sprintf(fw_name, "asihpi/dsp%04x.bin", nAdapter);

Well, you can simply add a version number suffix to the firmware
name, such as, dspxxx-032011.bin.  But, I think this versioned name is
needed only if the firmware has compatibility issue.  As long as the
firmware has a certain level of compatibility, we can reuse the same
name.


thanks,

Takashi