Commit 0d8cfeee authored by Chunfeng Yun's avatar Chunfeng Yun Committed by Greg Kroah-Hartman
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usb: xhci-mtk: fix random remote wakeup 



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: default avatarChunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20211102025004.29156-2-chunfeng.yun@mediatek.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 38269d2f

drivers/usb/host/xhci-mtk.c

+6 −5
Original line number Diff line number Diff line
@@ -245,12 +245,13 @@ 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");

	else /* workaound for platforms using low level latch */

		usleep_range(100, 200);



	return ret;

}

	return 0;

}



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;