[PATCH v6 1/5] usb: fsl: Set USB_EN bit to select ULPI phy

[PATCH v6 1/5] usb: fsl: Set USB_EN bit to select ULPI phy

[Yinbo Zhu]

From: Nikhil Badola <nikhil.badola@freescale.com>

Set USB_EN bit to select ULPI phy for USB controller version 2.5

Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
---
 drivers/usb/host/ehci-fsl.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index e3d0c1c25160..38674b7aa51e 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -122,6 +122,12 @@ static int fsl_ehci_drv_probe(struct platform_device *pdev)
 		tmp |= 0x4;
 		iowrite32be(tmp, hcd->regs + FSL_SOC_USB_CTRL);
 	}
+
+	/* Set USB_EN bit to select ULPI phy for USB controller version 2.5 */
+	if (pdata->controller_ver == FSL_USB_VER_2_5 &&
+	    pdata->phy_mode == FSL_USB2_PHY_ULPI)
+		iowrite32be(USB_CTRL_USB_EN, hcd->regs + FSL_SOC_USB_CTRL);
+
 	/*
 	 * Enable UTMI phy and program PTS field in UTMI mode before asserting
 	 * controller reset for USB Controller version 2.5
-- 
2.17.1

[PATCH v6 2/5] usb: phy: Workaround for USB erratum-A005728

[Yinbo Zhu]

From: Suresh Gupta <B42813@freescale.com>

PHY_CLK_VALID bit for UTMI PHY in USBDR does not set even
if PHY is providing valid clock. Workaround for this
involves resetting of PHY and check PHY_CLK_VALID bit
multiple times. If PHY_CLK_VALID bit is still not set even
after 5 retries, it would be safe to deaclare that PHY
clock is not available.
This erratum is applicable for USBDR less then ver 2.4.

Signed-off-by: Suresh Gupta <B42813@freescale.com>
Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
---
Change in v6:
		Indented the code in ehci-fsl.c 	

 drivers/usb/host/ehci-fsl.c | 37 ++++++++++++++++++++++++++-----------
 drivers/usb/host/ehci-fsl.h |  3 +++
 2 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 38674b7aa51e..8f3bf3efb038 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -183,6 +183,17 @@ static int fsl_ehci_drv_probe(struct platform_device *pdev)
 	return retval;
 }
 
+static bool usb_phy_clk_valid(struct usb_hcd *hcd)
+{
+	void __iomem *non_ehci = hcd->regs;
+	bool ret = true;
+
+	if (!(ioread32be(non_ehci + FSL_SOC_USB_CTRL) & PHY_CLK_VALID))
+		ret = false;
+
+	return ret;
+}
+
 static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
 			       enum fsl_usb2_phy_modes phy_mode,
 			       unsigned int port_offset)
@@ -226,6 +237,16 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
 		/* fall through */
 	case FSL_USB2_PHY_UTMI:
 	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
+		 * internal UTMI phy
+		 */
+		if (pdata->controller_ver > FSL_USB_VER_2_4 &&
+		    pdata->have_sysif_regs && !usb_phy_clk_valid(hcd)) {
+			dev_err(dev, "USB PHY clock invalid\n");
+			return -EINVAL;
+		}
+
 		if (pdata->have_sysif_regs && pdata->controller_ver) {
 			/* controller version 1.6 or above */
 			tmp = ioread32be(non_ehci + FSL_SOC_USB_CTRL);
@@ -249,17 +270,11 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
 		break;
 	}
 
-	/*
-	 * check PHY_CLK_VALID to determine phy clock presence before writing
-	 * to portsc
-	 */
-	if (pdata->check_phy_clk_valid) {
-		if (!(ioread32be(non_ehci + FSL_SOC_USB_CTRL) &
-		    PHY_CLK_VALID)) {
-			dev_warn(hcd->self.controller,
-				 "USB PHY clock invalid\n");
-			return -EINVAL;
-		}
+	if (pdata->have_sysif_regs &&
+	    pdata->controller_ver > FSL_USB_VER_1_6 &&
+	    !usb_phy_clk_valid(hcd)) {
+		dev_warn(hcd->self.controller, "USB PHY clock invalid\n");
+		return -EINVAL;
 	}
 
 	ehci_writel(ehci, portsc, &ehci->regs->port_status[port_offset]);
diff --git a/drivers/usb/host/ehci-fsl.h b/drivers/usb/host/ehci-fsl.h
index cbc422032e50..9d18c6e6ab27 100644
--- a/drivers/usb/host/ehci-fsl.h
+++ b/drivers/usb/host/ehci-fsl.h
@@ -50,4 +50,7 @@
 #define UTMI_PHY_EN             (1<<9)
 #define ULPI_PHY_CLK_SEL        (1<<10)
 #define PHY_CLK_VALID		(1<<17)
+
+/* Retry count for checking UTMI PHY CLK validity */
+#define UTMI_PHY_CLK_VALID_CHK_RETRY 5
 #endif				/* _EHCI_FSL_H */
-- 
2.17.1

[PATCH v6 3/5] usb: linux/fsl_device: Add platform member has_fsl_erratum_a006918

[Yinbo Zhu]

This patch is to add member has_fsl_erratum_a006918 in platform data

Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
---
 include/linux/fsl_devices.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/fsl_devices.h b/include/linux/fsl_devices.h
index cb2b46f57af3..5d231ce8709b 100644
--- a/include/linux/fsl_devices.h
+++ b/include/linux/fsl_devices.h
@@ -98,6 +98,7 @@ struct fsl_usb2_platform_data {
 	unsigned	has_fsl_erratum_14:1;
 	unsigned	has_fsl_erratum_a005275:1;
 	unsigned	has_fsl_erratum_a005697:1;
+	unsigned        has_fsl_erratum_a006918:1;
 	unsigned	check_phy_clk_valid:1;
 
 	/* register save area for suspend/resume */
-- 
2.17.1

[PATCH v6 4/5] usb: host: Stops USB controller init if PLL fails to lock

[Yinbo Zhu]

From: Ramneek Mehresh <ramneek.mehresh@freescale.com>

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@freescale.com>
Signed-off-by: Suresh Gupta <suresh.gupta@freescale.com>
Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
---
Change in v6:
		add a "Fall through" comment 	

 drivers/usb/host/ehci-fsl.c      | 10 +++++++++-
 drivers/usb/host/fsl-mph-dr-of.c |  3 ++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
index 8f3bf3efb038..86ae37086a74 100644
--- a/drivers/usb/host/ehci-fsl.c
+++ b/drivers/usb/host/ehci-fsl.c
@@ -234,8 +234,16 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
 		break;
 	case FSL_USB2_PHY_UTMI_WIDE:
 		portsc |= PORT_PTS_PTW;
-		/* fall through */
 	case FSL_USB2_PHY_UTMI:
+		/* Presence of this node "has_fsl_erratum_a006918"
+		 * in device-tree is used to stop USB controller
+		 * initialization in Linux
+		 */
+		if (pdata->has_fsl_erratum_a006918) {
+			dev_warn(dev, "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 4f8b8a08c914..762b97600ab0 100644
--- a/drivers/usb/host/fsl-mph-dr-of.c
+++ b/drivers/usb/host/fsl-mph-dr-of.c
@@ -224,13 +224,14 @@ static int fsl_usb2_mph_dr_of_probe(struct platform_device *ofdev)
 		of_property_read_bool(np, "fsl,usb-erratum-a005275");
 	pdata->has_fsl_erratum_a005697 =
 		of_property_read_bool(np, "fsl,usb_erratum-a005697");
+	pdata->has_fsl_erratum_a006918 =
+		of_property_read_bool(np, "fsl,usb_erratum-a006918");
 
 	if (of_get_property(np, "fsl,usb_erratum_14", NULL))
 		pdata->has_fsl_erratum_14 = 1;
 	else
 		pdata->has_fsl_erratum_14 = 0;
 
-
 	/*
 	 * Determine whether phy_clk_valid needs to be checked
 	 * by reading property in device tree
-- 
2.17.1

[PATCH v6 5/5] usb :fsl: Change string format for errata property

[Yinbo Zhu]

From: Nikhil Badola <nikhil.badola@freescale.com>

Remove USB errata checking code from driver. Applicability of erratum
is retrieved by reading corresponding property in device tree.
This property is written during device tree fixup.

Signed-off-by: Ramneek Mehresh <ramneek.mehresh@freescale.com>
Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
---
 drivers/usb/host/fsl-mph-dr-of.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/host/fsl-mph-dr-of.c b/drivers/usb/host/fsl-mph-dr-of.c
index 762b97600ab0..ae8f60f6e6a5 100644
--- a/drivers/usb/host/fsl-mph-dr-of.c
+++ b/drivers/usb/host/fsl-mph-dr-of.c
@@ -226,11 +226,8 @@ static int fsl_usb2_mph_dr_of_probe(struct platform_device *ofdev)
 		of_property_read_bool(np, "fsl,usb_erratum-a005697");
 	pdata->has_fsl_erratum_a006918 =
 		of_property_read_bool(np, "fsl,usb_erratum-a006918");
-
-	if (of_get_property(np, "fsl,usb_erratum_14", NULL))
-		pdata->has_fsl_erratum_14 = 1;
-	else
-		pdata->has_fsl_erratum_14 = 0;
+	pdata->has_fsl_erratum_14 =
+		of_property_read_bool(np, "fsl,usb_erratum-14");
 
 	/*
 	 * Determine whether phy_clk_valid needs to be checked
-- 
2.17.1

Re: [PATCH v6 4/5] usb: host: Stops USB controller init if PLL fails to lock

[Alan Stern]

On Wed, 5 Jun 2019, Yinbo Zhu wrote:

> From: Ramneek Mehresh <ramneek.mehresh@freescale.com>
> 
> 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@freescale.com>
> Signed-off-by: Suresh Gupta <suresh.gupta@freescale.com>
> Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
> ---
> Change in v6:
> 		add a "Fall through" comment 	
> 
>  drivers/usb/host/ehci-fsl.c      | 10 +++++++++-
>  drivers/usb/host/fsl-mph-dr-of.c |  3 ++-
>  2 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
> index 8f3bf3efb038..86ae37086a74 100644
> --- a/drivers/usb/host/ehci-fsl.c
> +++ b/drivers/usb/host/ehci-fsl.c
> @@ -234,8 +234,16 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
>  		break;
>  	case FSL_USB2_PHY_UTMI_WIDE:
>  		portsc |= PORT_PTS_PTW;
> -		/* fall through */
>  	case FSL_USB2_PHY_UTMI:
> +		/* Presence of this node "has_fsl_erratum_a006918"
> +		 * in device-tree is used to stop USB controller
> +		 * initialization in Linux
> +		 */
> +		if (pdata->has_fsl_erratum_a006918) {
> +			dev_warn(dev, "USB PHY clock invalid\n");
> +			return -EINVAL;
> +		}
> +
>  	case FSL_USB2_PHY_UTMI_DUAL:

This is bad.  You got rid of a "fall through" comment that was needed, 
and you failed to add another one where it was needed.

Alan Stern

>  		/* 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 4f8b8a08c914..762b97600ab0 100644
> --- a/drivers/usb/host/fsl-mph-dr-of.c
> +++ b/drivers/usb/host/fsl-mph-dr-of.c
> @@ -224,13 +224,14 @@ static int fsl_usb2_mph_dr_of_probe(struct platform_device *ofdev)
>  		of_property_read_bool(np, "fsl,usb-erratum-a005275");
>  	pdata->has_fsl_erratum_a005697 =
>  		of_property_read_bool(np, "fsl,usb_erratum-a005697");
> +	pdata->has_fsl_erratum_a006918 =
> +		of_property_read_bool(np, "fsl,usb_erratum-a006918");
>  
>  	if (of_get_property(np, "fsl,usb_erratum_14", NULL))
>  		pdata->has_fsl_erratum_14 = 1;
>  	else
>  		pdata->has_fsl_erratum_14 = 0;
>  
> -
>  	/*
>  	 * Determine whether phy_clk_valid needs to be checked
>  	 * by reading property in device tree
> 

RE: [EXT] Re: [PATCH v6 4/5] usb: host: Stops USB controller init if PLL fails to lock

[Yinbo Zhu]

> -----Original Message-----
> From: Alan Stern [mailto:stern@rowland.harvard.edu]
> Sent: 2019年6月5日 22:22
> To: Yinbo Zhu <yinbo.zhu@nxp.com>
> Cc: Xiaobo Xie <xiaobo.xie@nxp.com>; Greg Kroah-Hartman
> <gregkh@linuxfoundation.org>; Ramneek Mehresh
> <ramneek.mehresh@freescale.com>; Nikhil Badola
> <nikhil.badola@freescale.com>; Ran Wang <ran.wang_1@nxp.com>;
> linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; Jiafei Pan
> <jiafei.pan@nxp.com>
> Subject: [EXT] Re: [PATCH v6 4/5] usb: host: Stops USB controller init if PLL fails to
> lock
> 
> Caution: EXT Email
> 
> On Wed, 5 Jun 2019, Yinbo Zhu wrote:
> 
> > From: Ramneek Mehresh <ramneek.mehresh@freescale.com>
> >
> > 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@freescale.com>
> > Signed-off-by: Suresh Gupta <suresh.gupta@freescale.com>
> > Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
> > ---
> > Change in v6:
> >               add a "Fall through" comment
> >
> >  drivers/usb/host/ehci-fsl.c      | 10 +++++++++-
> >  drivers/usb/host/fsl-mph-dr-of.c |  3 ++-
> >  2 files changed, 11 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/host/ehci-fsl.c b/drivers/usb/host/ehci-fsl.c
> > index 8f3bf3efb038..86ae37086a74 100644
> > --- a/drivers/usb/host/ehci-fsl.c
> > +++ b/drivers/usb/host/ehci-fsl.c
> > @@ -234,8 +234,16 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
> >               break;
> >       case FSL_USB2_PHY_UTMI_WIDE:
> >               portsc |= PORT_PTS_PTW;
> > -             /* fall through */
> >       case FSL_USB2_PHY_UTMI:
> > +             /* Presence of this node "has_fsl_erratum_a006918"
> > +              * in device-tree is used to stop USB controller
> > +              * initialization in Linux
> > +              */
> > +             if (pdata->has_fsl_erratum_a006918) {
> > +                     dev_warn(dev, "USB PHY clock invalid\n");
> > +                     return -EINVAL;
> > +             }
> > +
> >       case FSL_USB2_PHY_UTMI_DUAL:
> 
> 
> You need to add a "Fall through" comment between these two cases.
> >       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
> 
> Alan Stern
> Hi Alan Stern,
>
> Your meaning is to remove "/* fall through*/" or add the erratum commont replace "/* fall through*/"
>
> Regards,
> Yinbo
> This is bad.  You got rid of a "fall through" comment that was needed, and you
> failed to add another one where it was needed.
> 
> Alan Stern
I don't get your meaning.
Yinbo
> 
> >               /* 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 4f8b8a08c914..762b97600ab0 100644
> > --- a/drivers/usb/host/fsl-mph-dr-of.c
> > +++ b/drivers/usb/host/fsl-mph-dr-of.c
> > @@ -224,13 +224,14 @@ static int fsl_usb2_mph_dr_of_probe(struct
> platform_device *ofdev)
> >               of_property_read_bool(np, "fsl,usb-erratum-a005275");
> >       pdata->has_fsl_erratum_a005697 =
> >               of_property_read_bool(np, "fsl,usb_erratum-a005697");
> > +     pdata->has_fsl_erratum_a006918 =
> > +             of_property_read_bool(np, "fsl,usb_erratum-a006918");
> >
> >       if (of_get_property(np, "fsl,usb_erratum_14", NULL))
> >               pdata->has_fsl_erratum_14 = 1;
> >       else
> >               pdata->has_fsl_erratum_14 = 0;
> >
> > -
> >       /*
> >        * Determine whether phy_clk_valid needs to be checked
> >        * by reading property in device tree
> >

RE: [EXT] Re: [PATCH v6 4/5] usb: host: Stops USB controller init if PLL fails to lock

[Yinbo Zhu]

> -----Original Message-----
> From: Yinbo Zhu
> Sent: 2019年6月6日 14:35
> To: Alan Stern <stern@rowland.harvard.edu>
> Cc: Xiaobo Xie <xiaobo.xie@nxp.com>; Greg Kroah-Hartman
> <gregkh@linuxfoundation.org>; Ramneek Mehresh
> <ramneek.mehresh@freescale.com>; Nikhil Badola
> <nikhil.badola@freescale.com>; Ran Wang <ran.wang_1@nxp.com>;
> linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; Jiafei Pan
> <jiafei.pan@nxp.com>
> Subject: RE: [EXT] Re: [PATCH v6 4/5] usb: host: Stops USB controller init if PLL
> fails to lock
> 
> 
> 
> > -----Original Message-----
> > From: Alan Stern [mailto:stern@rowland.harvard.edu]
> > Sent: 2019年6月5日 22:22
> > To: Yinbo Zhu <yinbo.zhu@nxp.com>
> > Cc: Xiaobo Xie <xiaobo.xie@nxp.com>; Greg Kroah-Hartman
> > <gregkh@linuxfoundation.org>; Ramneek Mehresh
> > <ramneek.mehresh@freescale.com>; Nikhil Badola
> > <nikhil.badola@freescale.com>; Ran Wang <ran.wang_1@nxp.com>;
> > linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org; Jiafei Pan
> > <jiafei.pan@nxp.com>
> > Subject: [EXT] Re: [PATCH v6 4/5] usb: host: Stops USB controller init
> > if PLL fails to lock
> >
> > Caution: EXT Email
> >
> > On Wed, 5 Jun 2019, Yinbo Zhu wrote:
> >
> > > From: Ramneek Mehresh <ramneek.mehresh@freescale.com>
> > >
> > > 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@freescale.com>
> > > Signed-off-by: Suresh Gupta <suresh.gupta@freescale.com>
> > > Signed-off-by: Yinbo Zhu <yinbo.zhu@nxp.com>
> > > ---
> > > Change in v6:
> > >               add a "Fall through" comment
> > >
> > >  drivers/usb/host/ehci-fsl.c      | 10 +++++++++-
> > >  drivers/usb/host/fsl-mph-dr-of.c |  3 ++-
> > >  2 files changed, 11 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/usb/host/ehci-fsl.c
> > > b/drivers/usb/host/ehci-fsl.c index 8f3bf3efb038..86ae37086a74
> > > 100644
> > > --- a/drivers/usb/host/ehci-fsl.c
> > > +++ b/drivers/usb/host/ehci-fsl.c
> > > @@ -234,8 +234,16 @@ static int ehci_fsl_setup_phy(struct usb_hcd *hcd,
> > >               break;
> > >       case FSL_USB2_PHY_UTMI_WIDE:
> > >               portsc |= PORT_PTS_PTW;
> > > -             /* fall through */
> > >       case FSL_USB2_PHY_UTMI:
> > > +             /* Presence of this node "has_fsl_erratum_a006918"
> > > +              * in device-tree is used to stop USB controller
> > > +              * initialization in Linux
> > > +              */
> > > +             if (pdata->has_fsl_erratum_a006918) {
> > > +                     dev_warn(dev, "USB PHY clock invalid\n");
> > > +                     return -EINVAL;
> > > +             }
> > > +
> > >       case FSL_USB2_PHY_UTMI_DUAL:
> >
> >
> > You need to add a "Fall through" comment between these two cases.
> > >       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
> >
> > Alan Stern
> > Hi Alan Stern,
> >
> > Your meaning is to remove "/* fall through*/" or add the erratum commont
> replace "/* fall through*/"
> >
> > Regards,
> > Yinbo
> > This is bad.  You got rid of a "fall through" comment that was needed,
> > and you failed to add another one where it was needed.
> >
> > Alan Stern
> I don't get your meaning.
> Yinbo
Hi Alan,

Your meaning is like following code change, isn't it? if no, could you give a example
                portsc |= PORT_PTS_PTW;
                /* fall through */
        case FSL_USB2_PHY_UTMI:
+               /* Presence of this node "has_fsl_erratum_a006918"
+                * in device-tree is used to stop USB controller
+                * initialization in Linux
+                */
+               if (pdata->has_fsl_erratum_a006918) {
+                       dev_warn(dev, "USB PHY clock invalid\n");
+                       return -EINVAL;
+               }
+
        case FSL_USB2_PHY_UTMI_DUAL:
                /* PHY_CLK_VALID bit is de-featured from all controller
Regards,
Yinbo.

> >
> > >               /* 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 4f8b8a08c914..762b97600ab0 100644
> > > --- a/drivers/usb/host/fsl-mph-dr-of.c
> > > +++ b/drivers/usb/host/fsl-mph-dr-of.c
> > > @@ -224,13 +224,14 @@ static int fsl_usb2_mph_dr_of_probe(struct
> > platform_device *ofdev)
> > >               of_property_read_bool(np, "fsl,usb-erratum-a005275");
> > >       pdata->has_fsl_erratum_a005697 =
> > >               of_property_read_bool(np, "fsl,usb_erratum-a005697");
> > > +     pdata->has_fsl_erratum_a006918 =
> > > +             of_property_read_bool(np, "fsl,usb_erratum-a006918");
> > >
> > >       if (of_get_property(np, "fsl,usb_erratum_14", NULL))
> > >               pdata->has_fsl_erratum_14 = 1;
> > >       else
> > >               pdata->has_fsl_erratum_14 = 0;
> > >
> > > -
> > >       /*
> > >        * Determine whether phy_clk_valid needs to be checked
> > >        * by reading property in device tree
> > >