diff -uNr linux-2.4.21/drivers/scsi/scsi_obsolete.c linux-2.4.21.ppc_large_timeout/drivers/scsi/scsi_obsolete.c
--- linux-2.4.21/drivers/scsi/scsi_obsolete.c	2003-08-25 10:47:05.000000000 +0200
+++ linux-2.4.21.ppc_large_timeout/drivers/scsi/scsi_obsolete.c	2003-08-25 11:23:56.000000000 +0200
@@ -118,9 +118,19 @@
 #define ABORT_TIMEOUT SCSI_TIMEOUT
 #define RESET_TIMEOUT SCSI_TIMEOUT
 #else
-#define SENSE_TIMEOUT (5*HZ/10)
-#define RESET_TIMEOUT (5*HZ/10)
-#define ABORT_TIMEOUT (5*HZ/10)
+/*
+ * FIXME XXX bump the timeout for some odd devices
+ * This is not an arch specific bug, after all
+ */
+#ifdef __powerpc64__
+#define SENSE_TIMEOUT (20*HZ)
+#define RESET_TIMEOUT (2*HZ)
+#define ABORT_TIMEOUT (25*HZ)
+#else
+#define SENSE_TIMEOUT (3*HZ/2)
+#define RESET_TIMEOUT (HZ)
+#define ABORT_TIMEOUT (3*HZ/2)
+#endif
 #endif
 
 
diff -uNr linux-2.4.21/drivers/scsi/scsi_scan.c linux-2.4.21.ppc_large_timeout/drivers/scsi/scsi_scan.c
--- linux-2.4.21/drivers/scsi/scsi_scan.c	2003-08-25 10:48:26.000000000 +0200
+++ linux-2.4.21.ppc_large_timeout/drivers/scsi/scsi_scan.c	2003-08-25 11:24:02.000000000 +0200
@@ -271,6 +271,17 @@
  */
 static unsigned int max_report_luns = 511;
 
+/* Some AChip ARC765 based DVD-ROM's take 15 or more seconds
+ * to reset.  A scan will fail if made right after a reset.
+ * It's completely broken device behaviour: SCSI specification
+ * says devices need to be able to respond to INQUIRY always
+ * (after a selection timeout ... of 250ms).
+ */
+#ifdef __powerpc64__
+static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ+25;
+#else
+static unsigned int scsi_inq_timeout = SCSI_TIMEOUT/HZ+4;
+#endif
 
 #ifdef MODULE
 
@@ -299,6 +309,9 @@
 MODULE_PARM_DESC(max_report_luns,
 		 "REPORT LUNS maximum number of LUNS received (should be"
 		 " between 1 and 16383)");
+
+MODULE_PARM(scsi_inq_timeout, "i");
+MODULE_PARM_DESC(scsi_inq_timeout, "Timeout (in seconds) waiting for devices to answer INQUIRY. Default is 6. Some non-compliant devices need more.");
 #else
 
 static int __init scsi_luns_setup(char *str)
@@ -433,6 +446,22 @@
 
 __setup("max_report_luns=", scsi_max_reportluns_setup);
 
+static int __init scsi_inq_timeout_setup(char *str)
+{
+	unsigned int tmp;
+
+	if (get_option(&str, &tmp) == 1) {
+		scsi_inq_timeout = tmp;
+		return 1;
+	} else {
+		printk("scsi_inq_timeout_setup: usage scsi_inq_timeout=n "
+		       "(n is in seconds and should be between 0 and 20)\n");
+		return 0;
+	}
+}
+
+__setup("scsi_inq_timeout=", scsi_inq_timeout_setup);
+
 #endif
 
 static void print_inquiry(unsigned char *data)
@@ -939,7 +967,7 @@
 	 */
 	memset (scsi_result, 0, 256);
 	
-	send_inquiry(SRpnt, scsi_result, inq_lun, SCSI_TIMEOUT+4*HZ, 36);
+	send_inquiry(SRpnt, scsi_result, inq_lun, HZ/2+scsi_inq_timeout*HZ, 36);
 
 	/*
 	 * Now that we don't do TEST_UNIT_READY anymore, we must be prepared
@@ -968,7 +996,7 @@
 
 	if (inq_len > 36 && ((unsigned char)scsi_result[2] & 0x7f) >= 3)
 		send_inquiry(SRpnt, scsi_result, inq_lun, 
-			     SCSI_TIMEOUT+4*HZ, inq_len);
+			     (1+scsi_inq_timeout)*HZ/2, inq_len);
 	/* We don't care about the result, actually, if the first INQUIRY
 	 * has been successful. */