incorrect parent refcounting in subr_firmware.c?

[John Baldwin]

On Wednesday, November 02, 2011 3:56:29 pm Navdeep Parhar wrote:
> I built a KLD with multiple firmware images, as shown here:
> 
> KMOD=foo
> FIRMWS= foo.bin:foo:1.0.0.0
> FIRMWS+=bar.bin:bar:1.0.0.0
> FIRMWS+= ...
> .include <bsd.kmod.mk>
> 
> "foo" is the parent firmware and a firmware_get(foo) can autoload the
> KLD.  "bar" and the rest are available only if the KLD is loaded (by
> whatever means).  This is reasonable and works as expected.  But if I
> just get and then put "foo" back, the KLD is not unloaded automatically.
> 
> The problem is that a reference is placed on the parent firmware when
> the other firmwares are registered (during module load).  I think this
> reference should be placed during firmware_get on the child.
> 
> What do people think about the attached patch?  It fixes things for me.

Hmm, what about the use case where a driver does:

f = firmware_get("foo");
firmware_put(f)
f = firmware_get("bar");
firmware_put(f)

Is that going to trigger multiple loads/unloads with this change?

-- 
John Baldwin