[PATCH] enable read prefetching on O2Micro bridges

[Daniel Ritz]

This one enables read prefetching on O2micro bridges. It fixes the problems
seen with the RME Hammerfall DSP.
Thanks to Eric Still from O2micro for the input.

against 2.6.6-rc3-bk

--- 1.153/include/linux/pci_ids.h	Thu Apr 29 11:41:09 2004
+++ edited/include/linux/pci_ids.h	Wed May  5 20:52:20 2004
@@ -1540,6 +1540,8 @@
 #define PCI_DEVICE_ID_O2_6730		0x673a
 #define PCI_DEVICE_ID_O2_6832		0x6832
 #define PCI_DEVICE_ID_O2_6836		0x6836
+#define PCI_DEVICE_ID_O2_6812		0x6872
+#define PCI_DEVICE_ID_O2_6933		0x6933
 
 #define PCI_VENDOR_ID_3DFX		0x121a
 #define PCI_DEVICE_ID_3DFX_VOODOO	0x0001
--- 1.54/drivers/pcmcia/yenta_socket.c	Wed Apr 14 23:06:58 2004
+++ edited/drivers/pcmcia/yenta_socket.c	Wed May  5 23:33:27 2004
@@ -668,6 +668,7 @@
 #include "ti113x.h"
 #include "ricoh.h"
 #include "topic.h"
+#include "o2micro.h"
 
 enum {
 	CARDBUS_TYPE_DEFAULT = -1,
@@ -676,7 +677,8 @@
 	CARDBUS_TYPE_TI12XX,
 	CARDBUS_TYPE_TI1250,
 	CARDBUS_TYPE_RICOH,
-	CARDBUS_TYPE_TOPIC97
+	CARDBUS_TYPE_TOPIC97,
+	CARDBUS_TYPE_O2MICRO,
 };
 
 /*
@@ -716,6 +718,10 @@
 	[CARDBUS_TYPE_TOPIC97]	= {
 		.override	= topic97_override,
 	},
+	[CARDBUS_TYPE_O2MICRO]	= {
+		.override	= o2micro_override,
+		.restore_state	= o2micro_restore_state,
+	},
 };
 
 
@@ -1098,6 +1104,13 @@
 
 	CB_ID(PCI_VENDOR_ID_TOSHIBA, PCI_DEVICE_ID_TOSHIBA_TOPIC97, TOPIC97),
 	CB_ID(PCI_VENDOR_ID_TOSHIBA, PCI_DEVICE_ID_TOSHIBA_TOPIC100, TOPIC97),
+
+	CB_ID(PCI_VENDOR_ID_O2, PCI_DEVICE_ID_O2_6729, O2MICRO),
+	CB_ID(PCI_VENDOR_ID_O2, PCI_DEVICE_ID_O2_6730, O2MICRO),
+	CB_ID(PCI_VENDOR_ID_O2, PCI_DEVICE_ID_O2_6812, O2MICRO),
+	CB_ID(PCI_VENDOR_ID_O2, PCI_DEVICE_ID_O2_6832, O2MICRO),
+	CB_ID(PCI_VENDOR_ID_O2, PCI_DEVICE_ID_O2_6836, O2MICRO),
+	CB_ID(PCI_VENDOR_ID_O2, PCI_DEVICE_ID_O2_6933, O2MICRO),
 
 	/* match any cardbus bridge */
 	CB_ID(PCI_ANY_ID, PCI_ANY_ID, DEFAULT),
--- 1.3/drivers/pcmcia/o2micro.h	Sat Oct 19 01:11:25 2002
+++ edited/drivers/pcmcia/o2micro.h	Wed May  5 23:32:39 2004
@@ -30,25 +30,6 @@
 #ifndef _LINUX_O2MICRO_H
 #define _LINUX_O2MICRO_H
 
-#ifndef PCI_VENDOR_ID_O2
-#define PCI_VENDOR_ID_O2		0x1217
-#endif
-#ifndef PCI_DEVICE_ID_O2_6729
-#define PCI_DEVICE_ID_O2_6729		0x6729
-#endif
-#ifndef PCI_DEVICE_ID_O2_6730
-#define PCI_DEVICE_ID_O2_6730		0x673a
-#endif
-#ifndef PCI_DEVICE_ID_O2_6832
-#define PCI_DEVICE_ID_O2_6832		0x6832
-#endif
-#ifndef PCI_DEVICE_ID_O2_6836
-#define PCI_DEVICE_ID_O2_6836		0x6836
-#endif
-#ifndef PCI_DEVICE_ID_O2_6812
-#define PCI_DEVICE_ID_O2_6812		0x6872
-#endif
-
 /* Additional PCI configuration registers */
 
 #define O2_MUX_CONTROL		0x90	/* 32 bit */
@@ -119,5 +100,31 @@
 #define  O2_MODE_E_SPKR_OUT	0x02
 #define  O2_MODE_E_LED_OUT	0x08
 #define  O2_MODE_E_SKTA_ACTV	0x10
+
+static int o2micro_override(struct yenta_socket *socket)
+{
+	/*
+	 * 'reserved' register at 0x94/D4. chaning it to 0xCA (8 bit) enables
+	 * read prefetching which for example makes the RME Hammerfall DSP
+	 * working. for some bridges it is at 0x94, for others at 0xD4. it's
+	 * ok to write to both registers on all O2 bridges.
+	 * from Eric Still, 02Micro.
+	 */
+	if (PCI_FUNC(socket->dev->devfn) == 0) {
+		config_writeb(socket, 0x94, 0xCA);
+		config_writeb(socket, 0xD4, 0xCA);
+	}
+
+	return 0;
+}
+
+static void o2micro_restore_state(struct yenta_socket *socket)
+{
+	/*
+	 * as long as read prefetch is the only thing in
+	 * o2micro_override, it's safe to call it from here
+	 */
+	o2micro_override(socket);
+}
 
 #endif /* _LINUX_O2MICRO_H */
--- 1.50/drivers/pcmcia/i82365.c	Sat Apr 17 10:36:21 2004
+++ edited/drivers/pcmcia/i82365.c	Tue Apr 20 21:44:05 2004
@@ -65,7 +65,6 @@
 #include "cirrus.h"
 #include "vg468.h"
 #include "ricoh.h"
-#include "o2micro.h"
 
 #ifdef DEBUG
 static const char *version =