Re: [PATCH][RESEND] i2c-i801: Add basic interrupt support

[Hans de Goede <j.w.r.degoede-fbo2DhPpy/Q@public.gmane.org>]

Jean Delvare wrote:
> 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.
> 

Erm, is this testing with or without your merging of the status flags defines? 
Maybe that is causing this?

Regards,

Hans


_______________________________________________
i2c mailing list
i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
http://lists.lm-sensors.org/mailman/listinfo/i2c