Hi Anand, On 07/12/2013 03:14 PM, Anand Kumar Santhanam wrote: > Hans, > > I reviewed the code changes and I did not see major differences except > for the fact that in adaptec driver we have 64 interrupt handlers to > handle 64 MSI-X. > This was optimized in open src driver to use only 1 interrupt handler. > Can you pls make this change to the open src driver (i.e have multiple > interrupt handlers for multiple MSI-X) and check?
I've looked at this more closely, and I wonder whether there isn't a race condition here. When an interrupt arrives you put the interrupt vector in pm8001_ha->int_vector, then schedule the tasklet. But what if two interrupts with different vectors arrive in quick succession before the tasklet got a chance to run? In that case the tasklet will only see the second vector, not the first. Rather scary. I have not actually seen any issues with this, but by definition race conditions are hard to reproduce and I haven't done any serious testing with this card. For now I will run with the quick and dirty msi.diff (http://hverkuil.home.xs4all.nl/msi.diff). I see two solutions: either use the 64 interrupt handlers as done in the adaptec driver, or you can change int_vector into a u64 and use it as a bitmask to record all interrupt vectors that have arrived. BTW, another difference between the linux kernel driver and the adaptec version are several of the defines in pm8001_defs.h: e.g. MPI_QUEUE is 256 in the adaptec driver, while it is 1024 in the kernel driver. There are other differences as well. Are all the changes in the kernel correct? I would like to have a confirmation of that before I am going to trust my data to this driver. It clearly hasn't been tested with actual hardware :-( Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
