Re: [PATCH] usb: dwc2: Fix HiKey regression caused by power_down feature

From: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
To: John Stultz <john.stultz@linaro.org>,
	lkml <linux-kernel@vger.kernel.org>
Cc: John Youn <John.Youn@synopsys.com>,
	Vardan Mikayelyan <mvardan@synopsys.com>,
	Artur Petrosyan <Arthur.Petrosyan@synopsys.com>,
	Grigor Tovmasyan <Grigor.Tovmasyan@synopsys.com>,
	Felipe Balbi <felipe.balbi@linux.intel.com>,
	"linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>
Subject: Re: [PATCH] usb: dwc2: Fix HiKey regression caused by power_down feature
Date: Mon, 21 May 2018 08:45:35 +0000	[thread overview]
Message-ID: <410670D7E743164D87FA6160E7907A5601313531E1@am04wembxa.internal.synopsys.com> (raw)
In-Reply-To: 1526690943-8211-1-git-send-email-john.stultz@linaro.org

Hi John,

On 5/19/2018 4:49 AM, John Stultz wrote:
> 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
> ...
> 
Could you please send full log to debug.

> 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;

power_down declared as int, suggested to update as follow:
	p->power_down = DWC2_POWER_DOWN_PARAM_NONE;

This can be accepted as temporary solution until we will fully debug 
hibernation feature for HiKey platform.

>   }
>   
>   static void dwc2_set_rk_params(struct dwc2_hsotg *hsotg)
> 