Messages in this thread | | | Date | Mon, 20 May 2013 14:40:55 -0600 | From | Stephen Warren <> | Subject | Re: [PATCH] pinctrl: sink pinctrldev_list_mutex |
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On 05/16/2013 01:48 AM, Linus Walleij wrote: > From: Linus Walleij <linus.walleij@linaro.org> > > The pinctrldev_list_mutex is sinked into the functions that > actually traverse the list and lock it there. The code makes > much more sense in this way. All the callers are in > non-performance critical paths and the code is way more > readable this way. > > Also refactor the function get_pinctrl_dev_from_devname() to > follow the design pattern of get_pinctrl_dev_from_of_node() > which is slightly simpler.
This seems fine on the surface, but I do have one question:
I think the pinctrl lock serves a couple of purposes:
1) Basic protection for accesses to the pinctrldev_list itself.
This patch seems just fine w.r.t. this point.
2) Preventing pinctrl drivers from being unregistered (and their modules unloaded) when some operation is being performed on/to them.
So, that means some code is written as follows:
lock find pinctrl device perform operation on pinctrl device unlock // only now could the found pinctrl device be unregistered
However, I think this patch changes that to the following for some operations:
lock find pinctrl device unlock // now the found pinctrl device can be unregistered perform operation on pinctrl device
Is this true here, or am I off-base?
If this isn't an issue, then the patch is fine by me. But, how is the unregistration prevented while the device is being operated on then?
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