RE: [PATCH v1 3/6] usb: host: Stops USB controller init if PLL fails to lock

[Yinbo Zhu]

-----Original Message-----
From: Sergei Shtylyov [mailto:sergei.shtylyov@xxxxxxxxxxxxxxxxxx] 
Sent: 2019å1æ21æ 16:17
To: Yinbo Zhu <yinbo.zhu@xxxxxxx>; Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: Xiaobo Xie <xiaobo.xie@xxxxxxx>; Jerry Huang <jerry.huang@xxxxxxx>; Ran Wang <ran.wang_1@xxxxxxx>; Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; Ramneek Mehresh <ramneek.mehresh@xxxxxxxxxxxxx>; Nikhil Badola <nikhil.badola@xxxxxxxxxxxxx>; Suresh Gupta <suresh.gupta@xxxxxxxxxxxxx>; linux-usb@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: Re: [PATCH v1 3/6] usb: host: Stops USB controller init if PLL fails to lock

>Hello!

> On 21.01.2019 6:13, Yinbo Zhu wrote:

> From: yinbo.zhu <yinbo.zhu@xxxxxxx>
> 
> USB erratum-A006918 workaround tries to start internal PHY inside 
> uboot (when PLL fails to lock). However, if the workaround also fails, 
> then USB initialization is also stopped inside Linux.
> Erratum-A006918 workaround failure creates "fsl,erratum_a006918"
> node in device-tree. Presence of this node in device-tree is used to 
> stop USB controller initialization in Linux
> 
> Signed-off-by: Ramneek Mehresh <ramneek.mehresh@xxxxxxxxxxxxx>
> Signed-off-by: Suresh Gupta <suresh.gupta@xxxxxxxxxxxxx>
> Signed-off-by: yinbo.zhu <yinbo.zhu@xxxxxxx>
> ---
>   drivers/usb/host/ehci-fsl.c      |    5 +++++
>   drivers/usb/host/fsl-mph-dr-of.c |    5 +++++
>   2 files changed, 10 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c 
> index a28ec1e..6884130 100644
> --- a/drivers/usb/host/ehci-fsl.c
> +++ b/drivers/usb/host/ehci-fsl.c
> @@ -224,6 +224,11 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
>   		portsc |= PORT_PTS_PTW;
>   		/* fall through */
>   	case FSL_USB2_PHY_UTMI:
> +		if (pdata->has_fsl_erratum_a006918) {
> +			pr_warn("fsl-ehci: USB PHY clock invalid\n");
> +			return -EINVAL;
> +		}
> +
>   	case FSL_USB2_PHY_UTMI_DUAL:
>   		/* PHY_CLK_VALID bit is de-featured from all controller
>   		 * versions below 2.4 and is to be checked only for diff --git 
> a/drivers/usb/host/fsl-mph-dr-of.c b/drivers/usb/host/fsl-mph-dr-of.c
> index 677f9d5..7e07701 100644
> --- a/drivers/usb/host/fsl-mph-dr-of.c
> +++ b/drivers/usb/host/fsl-mph-dr-of.c
> @@ -225,6 +225,11 @@ static int fsl_usb2_mph_dr_of_probe(struct platform_device *ofdev)
>   	pdata->has_fsl_erratum_a005697 =
>   		of_property_read_bool(np, "fsl,usb_erratum-a005697");
>   
> +	if (of_get_property(np, "fsl,erratum_a006918", NULL))

>    of_property_read_bool() perhaps?

Hi Sergei,

[PATCH v1 6/6] had modified it as this string format,
Please you note.

MBR, Yinbo
> +		pdata->has_fsl_erratum_a006918 = 1;
> +	else
> +		pdata->has_fsl_erratum_a006918 = 0;
> +
>   	/*
>   	 * Determine whether phy_clk_valid needs to be checked
>   	 * by reading property in device tree

> MBR, Sergei