Hi Jean, On 9/7/07, Jean Delvare <[EMAIL PROTECTED]> wrote: > Hi Greg, all, > > While platform_device.id is a u32, platform_device_add() handles "-1" as > a special id value. This has potential for confusion and bugs. One such > bug was reported to me by David Brownell: > > http://lists.lm-sensors.org/pipermail/i2c/2007-September/001787.html > > And since then I've found two other drivers affected (uartlite and > i2c-pxa). > > Could we at least make platform_device.id an int so as to clear up the > confusion? I doubt that the id will ever be a large number anyway. > > To go one step further, I am questioning the real value of this naming > exception for these "unique" platform devices. On top of the bugs I > mentioned above, it has potential for compatibility breakage: adding a > second device of the same type will rename the first one from "foo" to > "foo.0". It also requires specific checks in many individual platform > drivers. All this, as I understand it, for a purely aesthetic reason. I > don't think this is worth it. Would there be any objection to simply > getting rid of this exception and having all platform devices named > "foo.%d"? >
If a device has a <name>.<instance> scheme this implies possibility of having several instances of said device in a box. There are a few of platform devices that can only have one instance - for example i8042 keyboard controller (the -1 special handling came from me because i80420 name was very confusing - there wasn't a dot separator in the name back then). Drivers that allow multiple devices should not attempt to use -1 for the very first instance - this should eliminate potential for error and special handling that you are talking about. -- Dmitry - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
