Hans-J?rgen Koch wrote: > Am Sonntag 08 April 2007 19:36 schrieb Hans de Goede: >> Hans-J?rgen Koch wrote: >>> Am Sonntag 08 April 2007 15:51 schrieb Hans de Goede: >>>> The abituguru3 has a register which contains a motherboard ID. The >>>> current driver uses this ID, to look up info about the motherboard in a >>>> somewhat lenght table in the driver. >>> Can you elaborate your design decision a bit? My first idea would be to >>> have a sysfs file that delivers that motherboard ID and then do the >>> lookup in user space. >> As I don't want the abituguru3 driver to create entries in sysfs for >> sensors which aren't there, and as without the table in the driver I cannot >> be sure wether to create an in / temp / fan device for a given sensor >> address. > > Good point. Anyway, most sensor drivers have no way of knowing which of their > inputs are actually used. The LM93 driver I'm currently working on is a > monster that creates about 160 (!) sysfs files. I don't find it easy to > judge what's worse, having a few unused sysfs files or a large table in > kernel space. > Only 160? My abituguru 1/2 driver creates 177 for my motherboard and even more on some others (it can detect used versus unused inputs). And the abituguru3 driver can create 230 with known motherboards, and if i wouldn't use the table approach it would create 384 entries. Sorry I'm bragging here I couldn't help myself, and hopefully this also makes it even clearer why I went with the table approach. Also notice that the table (except for the used entry) could be made so that it is freed after module initialisation (currently it isn't). >> Last but not least doing things this way allows me to always give >> a proper reading without userspace needing to "guess" any further >> nescesarry calculations to get from the reading to an actual measurement. > > I agree that this is convenient, especially when reading sysfs values e.g. > from a script (without a library that could do table lookups). This is > probably a strong argument in favor of your table solution. > Yes its very convinient, in an ideal world all hwmon drivers would do this and libsensors would not be necessary. This is in no way meant to say that other drivers are written badly, I know the hardware makes it nearly impossible todo this for other drivers. Regards, Hans
