On Sat, 16 Aug 2008 18:50:13 +0200, Jean Delvare wrote: > On Sat, 16 Aug 2008 18:22:36 +0200, Ivo Manca wrote: > > Great and thanks. Am really curious about the stability of this code :) > > I'm hitting the first problems, with SMBus block transactions. They > fail on my ICH3 with use_irq=1. That's strange because these > transactions shouldn't make use of interrupts on the ICH3, but I still > see the IRQ handler being called 3 times, and then the transaction > times out. I'm debugging this now.
OK, I see what's going on. On this laptop, IRQ 9 is used by many things, not just SMBus. So the interrupt handler keeps being called even without SMBus activity or with polled-based SMBus activity. That's what happens during SMBus block transactions: the interrupt handler is called but not for us. However the interrupt handler thinks it is called by us and clears the status register value. This causes the polled-based loop to wait forever: by the time it looks for the status register value, it has been cleared. So we need to change the code in either of three ways: * Drop support for byte-by-byte block transactions. * Inhibit the interrupt handler during polled-based block transactions. * Convert the byteb-by-byte block transaction code to use interrupts instead of polling. The latter would be cleaner, but that's also more work. -- Jean Delvare _______________________________________________ i2c mailing list [email protected] http://lists.lm-sensors.org/mailman/listinfo/i2c
