While reviewing tmscsim, I noticed something, I didn't quite like /
understand. The driver takes the host_lock (with irqsave) at the entry to
the ISR, and releases it at the exit. And inside the ISR there are
potentially long busy-waits... Like

 	int ctr = 6000000; /* only try for about a second */
 	while( --ctr && !((dstate = DC390_read8 (DMA_Status)) &
 				DMA_XFER_DONE) && pSRB->SGToBeXferLen );

The attached patch is attempting to fix those places. Not sure if this is
a proper fix though. In my understanding, after looking through the code,
the host_lock is used to protect host-specific data and host-registers.
The ->queuecommand is already called with it help, so, one just,
basically, have to protect other contexts - interrupt, timer,... So, looks
mostly right.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>