diff mbox series

[2/2] usb: xhci-mtk: fix random remote wakeup

Message ID 20211102025004.29156-2-chunfeng.yun@mediatek.com (mailing list archive)
State Accepted
Commit 0d8cfeeef3f5a5966abce1903f80308be33280cb
Headers show
Series [1/2] usb: xhci-mtk: remove unnecessary error check | expand

Commit Message

Chunfeng Yun (云春峰) Nov. 2, 2021, 2:50 a.m. UTC 
Some platforms, e.g. 8183/8192, use low level latch way to keep
wakeup signal, it may latch a wrong signal if debounce more time,
and enable wakeup function earlier.
                   ____________________
ip_sleep      ____/                    \_____________
                           ___________________
wakeup_signal ____________/                   \______
                      _______________________________
wakeup_en     _______/
                      ^     ^
                      |(1)  |(2)
latch wakeup_signal mistakenly at (1), should latch it at (2);

Workaround: delay about 100us to enable wakeup, meanwhile decrease
debounce time.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
 drivers/usb/host/xhci-mtk.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
index adc5debcde88..91a664e8810d 100644
--- a/drivers/usb/host/xhci-mtk.c
+++ b/drivers/usb/host/xhci-mtk.c
@@ -245,11 +245,12 @@  static int xhci_mtk_host_disable(struct xhci_hcd_mtk *mtk)
 	/* wait for host ip to sleep */
 	ret = readl_poll_timeout(&ippc->ip_pw_sts1, value,
 			  (value & STS1_IP_SLEEP_STS), 100, 100000);
-	if (ret) {
+	if (ret)
 		dev_err(mtk->dev, "ip sleep failed!!!\n");
-		return ret;
-	}
-	return 0;
+	else /* workaound for platforms using low level latch */
+		usleep_range(100, 200);
+
+	return ret;
 }
 
 static int xhci_mtk_ssusb_config(struct xhci_hcd_mtk *mtk)
@@ -300,7 +301,7 @@  static void usb_wakeup_ip_sleep_set(struct xhci_hcd_mtk *mtk, bool enable)
 	case SSUSB_UWK_V1_1:
 		reg = mtk->uwk_reg_base + PERI_WK_CTRL0;
 		msk = WC0_IS_EN | WC0_IS_C(0xf) | WC0_IS_P;
-		val = enable ? (WC0_IS_EN | WC0_IS_C(0x8)) : 0;
+		val = enable ? (WC0_IS_EN | WC0_IS_C(0x1)) : 0;
 		break;
 	case SSUSB_UWK_V1_2:
 		reg = mtk->uwk_reg_base + PERI_WK_CTRL0;