On Tuesday 13 February 2007 07:47, Pavel Roskin wrote: > Hello! > > On Sun, 2007-02-11 at 14:17 +0100, Hesse, Christian wrote: > > lsmod shows a use count of 4294967295 (2^32 - 1), no oopses or the like. > > This is reproducable all the time. > > Although I cannot reproduce the problem (I'm on current wireless-dev), > here's my interpretation. > > The iwlwifi driver includes both a driver and a rate control algorithm. > It passes THIS_MODULE (i.e. a handle to itself) to the generic rate > control code, which locks the caller i.e. iwlwifi. Therefore, iwlwifi > has locked itself in memory. > > To counteract that, the driver "puts" the module, i.e. decreases its use > count after the rate control is registered. Conversely, the module > "gets" itself when the rate control is unregistered. > > One thing that is clearly wrong is that try_module_get() comes after > ieee80211_rate_control_unregister(), not before. This means that the > use count would go negative between those calls. If the kernel starts > checking for this, the driver is in trouble. > > Further, why do we need this self-locking/unlocking trick? The driver > can just set priv->rate_control.module to NULL and prevent self-locking. > > It would only make sense to put THIS_MODULE there is the rate control > were implemented as a separate module, which it probably a good idea in > the long term. > > But a simple fix would be just to get rid of all references to > THIS_MODULE and let the kernel do the right thing. > > Most likely, your kernel doesn't use the priv->rate_control.module field > to lock the module, so it would help in your case. > > Please try this patch: > > [ patch snipped ] This patch solves the problem. The module's use count is zero and I can unload and load the module. However I have processes in status D when restarting the device. Is it possible that some functions (i.e. escape_essid()) from old and new ieee80211 stack conflict? I will recompile my kernel without the old stack and see if anything changes. -- Regards, Chris
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