On Sun, 10 Aug 2008 22:08:03 +0200, Ivo Manca wrote: > Hey Jean, > > Jean Delvare wrote: > > Ah, really great! Thanks for working on this :) > > > > Is there any inherent difficulty to get interrupts to work with HW PEC? > > And with I2C block transactions? Or did you just not get around to > > doing it? > > To be honoust: I don't know a thing about HW PEC and was not able to > test it anyway. Therefor, I decided not to touch this part yet. I did > try to add support for interrupts with I2C block transactions. This > however caused various nasty problems.
PEC is an optional extra byte at the end of SMBus transactions, containing a checksum to detect transaction errors. It can be handled directly by the ICH4 hardware and later, thus the name "hwpec". The ICH3 can do software PEC but we don't support that. I don't think you need to care much about this as far as interrupts are concerned, this should be pretty transparent. I2C block writes shouldn't differ from other block transactions. I2C block reads OTOH are special in many aspects so I do expect special handling to be required for interrupt support. > That made me first want to test and implement basic interrupt support > before going there again. When I know for sure the basics work correctly > and stable (and when I know for sure I haven't made very stupid coding > mistakes), I'll try again to add support for block transactions :). This is a good strategy, no question about that. > > I've just given it a quick try on my old ICH3-M-based laptop and it > > seems to work fine there. The speed improvement compared to the polling > > code is very impressive. > > > > I'm going to do more tests on 2 other machines (with ICH5 and ICH7 > > respectively) and will report when I'm done. A patch review will also > > follow. > > Thanks! Glad to hear I didn't kill your laptop :). Testing is done, and all 3 systems survived and actually worked :) Well done! > > The i2c-i801 driver has changed a lot since then. Any chance you could > > respin the patches against 2.6.27-rc2? > > Sure, I'll try to respin it as soon as possible. Hopefully, that will be > tomorrow. Thanks. No need to hurry though, take your time. You may want to wait for my review so that you can address my concerns at the same time. -- Jean Delvare _______________________________________________ i2c mailing list [email protected] http://lists.lm-sensors.org/mailman/listinfo/i2c
