Hi, On Wed, Oct 15, 2014 at 06:43:40PM +0300, Tomi Valkeinen wrote: > >> Somehow omapfb device is still unbound from the driver, as I can then > >> bind it again, causing probe to be called. Which breaks everything. > >> > >> I would've thought that unbinding is not possible if remove is missing, > >> but that doesn't seem to be the case. I guess it just means that remove > >> is not called when the driver & device are unbound. > > > > if no remove it provided on platform_driver structure, platform bus > > assumes you have nothing to do on your ->remove(), so you end up leaking > > all resources you allocated on ->probe() (unless you *really* don't need > > to do anything on ->remove). > > Yep. That's quite odd, still. grep shows quite many uses of __exit_p(), > and all for remove callback. So, if you have something to release in > remove(), you should set it always, for both module and built-in. And if > you don't have anything to release, you would always just set .release > to NULL. > > I mean, what's the use case for __exit_p()? With a quick glance, at > least some of the other users also use __exit_p() the same way omapdss > does (i.e. in the wrong way). __exit_p() meant something else a few years back, perhaps those were left over from some tree-wide cleanups. > >> We have 18 __exit_p()s in omapdss and related drivers. I guess they are > >> all broken the same way. > > > > yup, I should've grepped. > > > >> Note that omapfb unbind & bind does not work even with this patch, but > >> results in a crash as some old state is left into omapdss. The same > >> happens also with unloading and loading omapfb module (but keeping > >> omapdss module loaded). > > > > It worked fine for me. I unbound and bound omapfb multiple times. > > Hmm, ok. Odd, the bug was quite clear and I think it should happen every > time. Well, I was using omap4. If you used AM4xx, that's basically omap3 > DSS. Maybe there's a diff there. could very well be :-) > >> So there seems to be more issues around this. > > > > quite a few more, I'd say > > Yep, I'll have a look at this. alright -- balbi
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