ssb: when needed, reject IM input while disabling device

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/ssb/main.c

@@ -1220,7 +1220,7 @@ static int ssb_wait_bits(struct ssb_device *dev, u16 reg, u32 bitmask,
 
 void ssb_device_disable(struct ssb_device *dev, u32 core_specific_flags)
 {
-	u32 reject;
+	u32 reject, val;
 
 	if (ssb_read32(dev, SSB_TMSLOW) & SSB_TMSLOW_RESET)
 		return;
@@ -1229,12 +1229,26 @@ void ssb_device_disable(struct ssb_device *dev, u32 core_specific_flags)
 	ssb_write32(dev, SSB_TMSLOW, reject | SSB_TMSLOW_CLOCK);
 	ssb_wait_bits(dev, SSB_TMSLOW, reject, 1000, 1);
 	ssb_wait_bits(dev, SSB_TMSHIGH, SSB_TMSHIGH_BUSY, 1000, 0);
+
+	if (ssb_read32(dev, SSB_IDLOW) & SSB_IDLOW_INITIATOR) {
+		val = ssb_read32(dev, SSB_IMSTATE);
+		val |= SSB_IMSTATE_REJECT;
+		ssb_write32(dev, SSB_IMSTATE, val);
+		ssb_wait_bits(dev, SSB_IMSTATE, SSB_IMSTATE_BUSY, 1000, 0);
+	}
+
 	ssb_write32(dev, SSB_TMSLOW,
 		    SSB_TMSLOW_FGC | SSB_TMSLOW_CLOCK |
 		    reject | SSB_TMSLOW_RESET |
 		    core_specific_flags);
 	ssb_flush_tmslow(dev);
 
+	if (ssb_read32(dev, SSB_IDLOW) & SSB_IDLOW_INITIATOR) {
+		val = ssb_read32(dev, SSB_IMSTATE);
+		val &= ~SSB_IMSTATE_REJECT;
+		ssb_write32(dev, SSB_IMSTATE, val);
+	}
+
 	ssb_write32(dev, SSB_TMSLOW,
 		    reject | SSB_TMSLOW_RESET |
 		    core_specific_flags);

include/linux/ssb/ssb_regs.h

@@ -85,6 +85,8 @@
 #define  SSB_IMSTATE_AP_RSV	0x00000030 /* Reserved */
 #define  SSB_IMSTATE_IBE	0x00020000 /* In Band Error */
 #define  SSB_IMSTATE_TO		0x00040000 /* Timeout */
+#define  SSB_IMSTATE_BUSY	0x01800000 /* Busy (Backplane rev >= 2.3 only) */
+#define  SSB_IMSTATE_REJECT	0x02000000 /* Reject (Backplane rev >= 2.3 only) */
 #define SSB_INTVEC		0x0F94     /* SB Interrupt Mask */
 #define  SSB_INTVEC_PCI		0x00000001 /* Enable interrupts for PCI */
 #define  SSB_INTVEC_ENET0	0x00000002 /* Enable interrupts for enet 0 */