[PATCH 3/9] usb: xhci-mtk: check clock stability of U3_MAC

From: Chunfeng Yun
Date: Wed Sep 27 2017 - 05:23:32 EST


This is useful to find out the root cause when the Super Speed doesn't
work. Such as when the T-PHY is switched to PCIe or SATA, and affects
Super Speed function, the check will fail.

Signed-off-by: Chunfeng Yun <chunfeng.yun@xxxxxxxxxxxx>
---
drivers/usb/host/xhci-mtk.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index 9502ca4..7a92bb7 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -43,6 +43,7 @@

/* ip_pw_sts1 register */
#define STS1_IP_SLEEP_STS BIT(30)
+#define STS1_U3_MAC_RST BIT(16)
#define STS1_XHCI_RST BIT(11)
#define STS1_SYS125_RST BIT(10)
#define STS1_REF_RST BIT(8)
@@ -125,6 +126,9 @@ static int xhci_mtk_host_enable(struct xhci_hcd_mtk *mtk)
check_val = STS1_SYSPLL_STABLE | STS1_REF_RST |
STS1_SYS125_RST | STS1_XHCI_RST;

+ if (mtk->num_u3_ports)
+ check_val |= STS1_U3_MAC_RST;
+
ret = readl_poll_timeout(&ippc->ip_pw_sts1, value,
(check_val == (value & check_val)), 100, 20000);
if (ret) {
--
1.7.9.5