It's a panic that is supposed to check that the state machine in operating correctly. To start a dma transfer the device is supposed to be in Transfer_Data_Dma (which some device access writes put in in) and the dmaState is supposed to be in Dma_Transfer (as opposed to some other phase of the DMA). Which one is incorrect in the panic?
Are you identifying the device (PCI device/vendor IDs) exactly as we do for Alpha (it ends up being a Intel PIIX IDE controller or something). If you're not you might be stumbling on some un- implemented feature. If you are, then I would guess that it's something to do with I/O writes not getting to the device correctly (either order or just disappearing). You can boot the Alpha version with DPRINTFs and see the correct sequence of commands and then compare that to the DMA that dies for some more insight. Ali On Apr 8, 2009, at 5:46 PM, Steve Reinhardt wrote: > I don't know much about IDE either, but it may have more to do with > DMA in general than with IDE specifically. What is the specific > panic that you're getting (i.e., the actual output)? > > Steve > > On Wed, Apr 8, 2009 at 1:36 AM, Gabe Black <[email protected]> > wrote: > Anybody? The ATA spec I have is -really- long and I'm not feeling > ambitious enough to read it :). I don't know if this would be > covered in > there anyway. > > Gabe > > Gabe Black wrote: > > I have an SMP kernel booting and running the init process, but > I'm > > getting the following panic from the IDE disk on line 321 in > > dev/ide_disk.cc: > > > > void > > IdeDisk::doDmaTransfer() > > { > > if (dmaState != Dma_Transfer || devState != Transfer_Data_Dma) > > panic("Inconsistent DMA transfer state: dmaState = %d > devState = > > %d\n", > > dmaState, devState); > > > > > > I'm not familiar with the details of IDE. Could someone please > give me a > > 30 second explanation of what this is checking? > > > > Gabe > > _______________________________________________ > > m5-dev mailing list > > [email protected] > > http://m5sim.org/mailman/listinfo/m5-dev > > > > _______________________________________________ > m5-dev mailing list > [email protected] > http://m5sim.org/mailman/listinfo/m5-dev > > _______________________________________________ > m5-dev mailing list > [email protected] > http://m5sim.org/mailman/listinfo/m5-dev _______________________________________________ m5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/m5-dev
