On Thu, 4 May 2006, Andrew de Quincey wrote: > > First, I would like it better if symbol_put_addr() would be fixed > > so we could use my dvb_detach() idea ;-) > > It would mean that no changes to the frontend drivers are > > necessary at all. > > I suppose Trent's patch to fix it would also provide a good indicator as to > whether people think symbol_put_addr() is going to be kept or not, depending > on its reception by lkml (or whoever its sent to). I posted my patch on lkml, but no one responded. I'm not a kernel developer, so that's not too surprising. I doubt anyone who cares about the symbol_xxx code in the kernel even read it. I'm used to it. My patch to fix the broken makefile to this list was totally ignored too. Maybe if someone else better known posted my patch, it would get attention. Maybe, using symbol_put_addr() need not wait for a patched kernel. Could a fixed version be included in dvb-core that is compiled on older kernels? I already tried a version with symbol_put_addr (with my patch to fix it) that doesn't require any extra modification of the demodulator drivers. In dvb_attach(), I just used the code I already posted here. It does not do a symbol_put() and so keeps the lock on the symbol. In the card driver, I modified the dvb_remove() function to call symbol_put_addr() on the release() method from the frontend ops struct. Since the locking is at the module level, not the symbol level, it doesn't have to be the same symbol that was used in symbol_get(), just a symbol from the same module. This worked fine. The frontend module was auto-loaded if it wasn't loaded already. The FE can't be unloaded while the card driver is still loaded. When the card driver is unloaded, the FE use count is decremented, allowing the FE to be unloaded. A driver doesn't use dvb_attach() should be able to use the same frontend module as one that does. card drivers that only support a single FE have no reason to use dvb_attach(), and so don't have to. > > Doesn't this drop the refcount to the frontend module, and > > raise the refcount to the card driver? I.e. the frontend > > module can be unloaded while it is in use? > > Arrgh yes :( Dunno what the hell I was thinking! That's what I thought too when I first looked at the patch. I thought maybe I was missing something and was waiting until I actually tried it before I responded. _______________________________________________ linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
