From: Kumba <[EMAIL PROTECTED]> Date: Tue, 26 Jul 2005 19:33:52 -0400
> The Floppy drive on Sun Blade 100 has never worked. I might be off > on this, but I believe it hangs off of an ISA bus built into the > system (or some bus), and no one's ever invested the time to detect > it. It's not a matter of detection, it's working around the brain damaged design of this thing. The floppy device wants to do ISA DMA, but on the ISA bus it is illegal for other agents to issue ISA I/O port operations while a DMA is in progress. The ISA bus has a signal that the processor is supposed to use to determine when DMA is in progress and thus I/O port operations cannot be initiated, but there is no hookup for this to the UltraSPARC chip in the SB100. Thus the only way to handle this is to make the current thread of execution sleep if it tries to do an I/O port access while a floppy DMA is in progress, and since we can't sleep in interrupt handler context there is no way to implement this awefully gross workaround for hardware mis-design. Just get a USB memory stick if you want small portable storage. The floppy device on the SB100 is unlikely to ever be supported. - To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
