[PATCH 3/5] thunderbolt: Verify Router Ready bit is set after router enumeration

[Gil Fine <gil.fine@linux.intel.com>]

The USB4 Connection Manager guide specifies that after enumerating a
router, the Connection Manager shall verify that the Router Ready bit
(ROUTER_CS_6.RR) has been set to ensure hardware configuration has completed.
Currently, this step is missing from the enumeration sequence.

Add this check to follow the Connection Manager guide more closely.

Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
---
 drivers/thunderbolt/switch.c  | 5 +++++
 drivers/thunderbolt/tb_regs.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c
index e7faa203b782..11e8c1dd3090 100644
--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -2641,6 +2641,11 @@ int tb_switch_configure(struct tb_switch *sw)
 			return ret;
 
 		ret = usb4_switch_setup(sw);
+		if (ret)
+			return ret;
+
+		ret = tb_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_RR,
+					     ROUTER_CS_6_RR, 500);
 	} else {
 		if (sw->config.vendor_id != PCI_VENDOR_ID_INTEL)
 			tb_sw_warn(sw, "unknown switch vendor id %#x\n",
diff --git a/drivers/thunderbolt/tb_regs.h b/drivers/thunderbolt/tb_regs.h
index 71bed02a6974..7e65bc9bcb12 100644
--- a/drivers/thunderbolt/tb_regs.h
+++ b/drivers/thunderbolt/tb_regs.h
@@ -216,6 +216,7 @@ struct tb_regs_switch_header {
 #define ROUTER_CS_6_WOPS			BIT(2)
 #define ROUTER_CS_6_WOUS			BIT(3)
 #define ROUTER_CS_6_HCI				BIT(18)
+#define ROUTER_CS_6_RR				BIT(24)
 #define ROUTER_CS_6_CR				BIT(25)
 #define ROUTER_CS_7				0x07
 #define ROUTER_CS_9				0x09
-- 
2.43.0