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From:   John Stultz <john.stultz@linaro.org>
To:     lkml <linux-kernel@vger.kernel.org>
Cc:     John Stultz <john.stultz@linaro.org>,
        John Youn <johnyoun@synopsys.com>,
        Vardan Mikayelyan <mvardan@synopsys.com>,
        Artur Petrosyan <arturp@synopsys.com>,
        Grigor Tovmasyan <tovmasya@synopsys.com>,
        Felipe Balbi <felipe.balbi@linux.intel.com>,
        linux-usb@vger.kernel.org
Subject: [PATCH] usb: dwc2: Fix HiKey regression caused by power_down feature
Date:   Fri, 18 May 2018 17:49:03 -0700
Message-Id: <1526690943-8211-1-git-send-email-john.stultz@linaro.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In 4.17-rc, commit 03ea6d6e9e1f ("usb: dwc2: Enable power down")
caused the HiKey board to not correctly handle switching between
usb-gadget and usb-host mode.

Unplugging the OTG port would result in:
[   42.240973] dwc2 f72c0000.usb: dwc2_restore_host_registers: no host registers to restore
[   42.249066] dwc2 f72c0000.usb: dwc2_host_exit_hibernation: failed to restore host registers

And the USB-host ports would not function.

And plugging in the OTG port, we would see:
[   46.046557] WARNING: CPU: 3 PID: 6 at drivers/usb/dwc2/gadget.c:260 dwc2_hsotg_init_fifo+0x194/0x1a0
[   46.055761] CPU: 3 PID: 6 Comm: kworker/u16:0 Not tainted 4.17.0-rc5-00030-ge67da8c #231
[   46.055767] Hardware name: HiKey Development Board (DT)
[   46.055784] Workqueue: dwc2 dwc2_conn_id_status_change
...

Thus, this patch sets the hisi params to disable the power_down
flag by default, and gets thing working again.

Cc: John Youn <johnyoun@synopsys.com>
Cc: Vardan Mikayelyan <mvardan@synopsys.com>
Cc: Artur Petrosyan <arturp@synopsys.com>
Cc: Grigor Tovmasyan <tovmasya@synopsys.com>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
 drivers/usb/dwc2/params.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/dwc2/params.c b/drivers/usb/dwc2/params.c
index f03e418..96b1b25 100644
--- a/drivers/usb/dwc2/params.c
+++ b/drivers/usb/dwc2/params.c
@@ -70,6 +70,7 @@ static void dwc2_set_his_params(struct dwc2_hsotg *hsotg)
 		GAHBCFG_HBSTLEN_SHIFT;
 	p->uframe_sched = false;
 	p->change_speed_quirk = true;
+	p->power_down = false;
 }
 
 static void dwc2_set_rk_params(struct dwc2_hsotg *hsotg)
-- 
2.7.4