patch-2.4.22 linux-2.4.22/drivers/scsi/aha152x.c

• Lines: 31
• Date: 2003-08-25 04:44:42.000000000 -0700
• Orig file: linux-2.4.21/drivers/scsi/aha152x.c
• Orig date: 2003-06-13 07:51:36.000000000 -0700

diff -urN linux-2.4.21/drivers/scsi/aha152x.c linux-2.4.22/drivers/scsi/aha152x.c
@@ -1930,12 +1930,30 @@
 static void intr(int irqno, void *dev_id, struct pt_regs *regs)
 {
 	struct Scsi_Host *shpnt = lookup_irq(irqno);
+	unsigned char rev, dmacntrl0;
 
 	if (!shpnt) {
 		printk(KERN_ERR "aha152x: catched interrupt %d for unknown controller.\n", irqno);
 		return;
 	}
 
+	/*
+	 * Read a couple of registers that are known to not be all 1's. If
+	 * we read all 1's (-1), that means that either:
+	 * a. The host adapter chip has gone bad, and we cannot control it,
+	 * OR
+	 * b. The host adapter is a PCMCIA card that has been ejected
+	 * In either case, we cannot do anything with the host adapter at
+	 * this point in time. So just ignore the interrupt and return.
+	 * In the latter case, the interrupt might actually be meant for
+	 * someone else sharing this IRQ, and that driver will handle it
+	 */
+	rev = GETPORT(REV);
+	dmacntrl0 = GETPORT(DMACNTRL0);
+	if ((rev == 0xFF) && (dmacntrl0 == 0xFF)) {
+		return;
+	}
+
 	/* no more interrupts from the controller, while we're busy.
 	   INTEN is restored by the BH handler */
 	CLRBITS(DMACNTRL0, INTEN);