I am purposely removing kernelnewbies from the CC list, as it seems quite irrelevant for this discussion. On Wed, 5 Oct 2011 22:19:55 -0700, Guenter Roeck wrote: > On Thu, Oct 06, 2011 at 12:06:59AM -0400, Himanshu Chauhan wrote: > > Hi, > > > > > I can not comment on the merits of your patch. Unless I am missing > > > something, which may well be since I only spent a couple of minutes on > > > it, other device classes don't seem to provide a similar API, so I don't > > > know if or why it would make sense for hwmon. Maybe a driver which wants > > > to register a character device interface should do so independently of > > > hwmon. > > > > > > > The idea here is to sit in the same class directory as of hwmon. Devices > > registered with this interface will have "dev" under, for example, > > /sys/class/hwmon/hwmon0/dev. To do the same inside the driver will be > > a bit more involved than a call. > > > > In my opinion other classes should also have similar interfaces. > > > I think you'll have to spend some more time and effort explaining the "what for". > > Apparently no other device class needs this functionality so far, yet you > suggest that such an interface should exist for all device classes. Actually a lot of class devices do have a device node: $ ls -1 /sys/class/*/*/dev | wc -l 252 This includes block, drm, dvb, input, msr, sound and tty class devices, to name just a few. But this isn't the problem. All these are documented in Documentation/devices.txt, and have a properly defined API. There is no such thing for hwmon devices at this point. > But you do so without explanation, or in other words without use case. This is indeed the key point. Creating a device node is pointless without a standard API to make use of it. So Himanshu will have to document that first. > I for my part have no idea what you would use or need this new interface for, > and if there would be other less intrusive means to accomplish the same goal. > And I would want to see really good reasons to make a change like this. Another good point. > Specifically looking at the hwmon subsystem, you are expected to use the lm-sensors > library to access all hwmon attributes. So I would expect your explanation to include > exactly what you want to accomplish and why, details why you believe that you can not > use the lm-sensors library, why you believe that the current infrastructure > does not provide the means you need to accomplish your goals, and why you > think that the existing infrastructure can not be modified to let you accomplish > what you want to do without such a - from a conceptual perspective - substantial change. I again agree. Which means that Himanshu is still 3 steps away from getting his patch accepted: * Explaining why the current sysfs interface is insufficient and can't be fixed. * Getting official device node numbers registered for hwmon use. * Defining an API for these device nodes. Before then, there's no point in resending this patch, it will be rejected. -- Jean Delvare _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
