Re: lockup booting 8.0-CURRENT-200811 snap image

On Tuesday 16 December 2008 10:18:16 am John Baldwin wrote:
> So the real fix is that we need to disable memory and I/O decoding int  
> the PCI command register when messing with the BARs. One thing to be  
> careful with is we can't do any console I/O (i.e. printfs) while the  
> BAR is disabled. I will come up with a proper patch when I get back to  
> a real computer.

Please try this instead (compiled, but not run-tested):

--- //depot/vendor/freebsd/src/sys/dev/pci/pci.c	2008/11/13 20:00:29
+++ //depot/user/jhb/acpipci/dev/pci/pci.c	2009/01/15 21:40:48
_at__at_ -2291,9 +2291,27 _at__at_
 	struct resource *res;
 
 	map = PCIB_READ_CONFIG(pcib, b, s, f, reg, 4);
+
+	/*
+	 * Disable decoding via the command register before
+	 * determining the BAR's length since we will be placing them
+	 * in a weird state.
+	 */
+	cmd = PCIB_READ_CONFIG(pcib, b, s, f, PCIR_COMMAND, 2);
+	PCIB_WRITE_CONFIG(pcib, b, s, f, PCIR_COMMAND,
+	    cmd & ~(PCI_BAR_MEM(map) ? PCIM_CMD_MEMEN : PCIM_CMD_PORTEN), 2);
+
+	/*
+	 * Determine the BAR's length by writing all 1's.  The bottom
+	 * log_2(size) bits of the BAR will stick as 0 when we read
+	 * the value back.
+	 */
 	PCIB_WRITE_CONFIG(pcib, b, s, f, reg, 0xffffffff, 4);
 	testval = PCIB_READ_CONFIG(pcib, b, s, f, reg, 4);
+
+	/* Restore the BAR and command register. */
 	PCIB_WRITE_CONFIG(pcib, b, s, f, reg, map, 4);
+	PCIB_WRITE_CONFIG(pcib, b, s, f, PCIR_COMMAND, cmd, 2);
 
 	if (PCI_BAR_MEM(map))
 		type = SYS_RES_MEMORY;

-- 
John Baldwin