Hi Corey: * Corey Minyard <cminyard at mvista.com> [2005-01-19 16:10:31 -0600]: > I'm the maintainer of the IPMI driver, and there is a new function that > needs to be added that does IPMI over SMBUS. This requires some minor > changes to the I2C interface to support a special function of the IPMI > driver. > > The IPMI driver support the ability to store panic information into the > Systen Event Log (SEL) of the IPMI controller. Since it does this at > panic time, the system can no longer schedule. Thus the driver has to > be able to do this without jiffies or scheduling. There are also some > watchdog operations that need to happen at panic time that also need this. > > I've attached a patch that modifies the I2C bus drivers to add the > capability to use a delay. There's some more work to do on the IPMI > driver portion, still, but I thought I would socialize this with the > sensors group first. This is just a first shot, I'm sure I've missed > something. > (...) Well, wait_event_interruptible_timeout() schedules, so at a quick glance this will not work for i2c-ibm_iic at least. But more generally... I started to rewrite i2c-i801 [1] to use interrupts rather than pure polling as it does now, so I'm interested to know: how can the panic-time operation work for bus drivers that need interrupts? [1] http://archives.andrew.net.au/lm-sensors/msg28496.html Regards, -- Mark M. Hoffman mhoffman at lightlink.com
