On Wed, Mar 23, 2011 at 12:32 AM, Paul Mundt <lethal@xxxxxxxxxxxx> wrote: > On Wed, Mar 23, 2011 at 12:22:05AM +0900, Magnus Damm wrote: >> On Tue, Mar 22, 2011 at 11:33 PM, Paul Mundt <lethal@xxxxxxxxxxxx> wrote: >> > On Tue, Mar 22, 2011 at 02:28:55PM +0000, Mark Brown wrote: >> >> On Tue, Mar 22, 2011 at 11:26:19PM +0900, Magnus Damm wrote: >> >> >> >> > The tca6416 driver makes use of the I2C bus for chatting >> >> > with the actual hardware device. Without this patch both >> >> > the I2C bus driver and the tca6416 driver are initialized >> >> > at the subsys_initcall() level. This may lead to problems >> >> > with the tca6416 driver being initialized before the I2C >> >> > bus driver. >> >> >> >> While this change seems reasonable I'm curious what the problems caused >> >> by out of order registration are? >> > >> > I'm also curious as to why link order isn't a sufficient gaurantee like >> > it is for everyone else? >> >> I believe all other i2c keyboard drivers use module_init(). >> > We do not change initcall ordering around unless there is a reason to do > so, as it's assumed that a given initcall has been chosen for a reason. Yes, obviously this driver is special and all other keypad drivers are wrong. It would be interesting to hear why subsys_initcall() was put there in the first place. > You have hit upon a bug or at least something timing related causing you > a delay and so have elected to push it down a level. That is of course > fine, but none of that is anywhere in your commit text leaving us to try > and figure out what exactly the point of this exercise is. The keypad driver tries to use the I2C bus before the I2C bus driver is initialized. Isn't that a pretty good reason to change the initcall order? > Usually "because everyone else is doing it" and another driver is not, > there's a reason for that driver doing things differently. There are > certainly enough cases where initcall and link ordering is strongly > ordered for a reason that cosmetic/janitorial fixes are best rejected out > of hand. So let's hear what other people have to say about this. > You had a reason, great. Next time put it in your commit text. Whatever. Let me know which lines you'd like to add and I'll send a V2. / magnus -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
