[PATCH v4 1/2] xhci-ext-caps.c: Add property to disable Intel SW switch

[PATCH v4 1/2] xhci-ext-caps.c: Add property to disable Intel SW switch

[Saranya Gopal]

In platforms like Cherrytrail, 'SW switch enable' bit
should not be enabled for role switch. This patch
adds a property to Intel USB Role Switch platform driver
to denote that SW switch should be disabled in
Cherrytrail devices.

Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>
Signed-off-by: Balaji Manoharan <m.balaji@intel.com>
Suggested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
 changes since v3: none
 changes since v2: Added suggested-by tag
 changes since v1: none

 drivers/usb/host/xhci-ext-caps.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/usb/host/xhci-ext-caps.c b/drivers/usb/host/xhci-ext-caps.c
index 399113f..f498160 100644
--- a/drivers/usb/host/xhci-ext-caps.c
+++ b/drivers/usb/host/xhci-ext-caps.c
@@ -6,11 +6,20 @@
  */
 
 #include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/pci.h>
 #include "xhci.h"
 
 #define USB_SW_DRV_NAME		"intel_xhci_usb_sw"
 #define USB_SW_RESOURCE_SIZE	0x400
 
+#define PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI	0x22b5
+
+static const struct property_entry role_switch_props[] = {
+	PROPERTY_ENTRY_BOOL("sw_switch_disable"),
+	{},
+};
+
 static void xhci_intel_unregister_pdev(void *arg)
 {
 	platform_device_unregister(arg);
@@ -21,6 +30,7 @@ static int xhci_create_intel_xhci_sw_pdev(struct xhci_hcd *xhci, u32 cap_offset)
 	struct usb_hcd *hcd = xhci_to_hcd(xhci);
 	struct device *dev = hcd->self.controller;
 	struct platform_device *pdev;
+	struct pci_dev *pci = to_pci_dev(dev);
 	struct resource	res = { 0, };
 	int ret;
 
@@ -43,6 +53,14 @@ static int xhci_create_intel_xhci_sw_pdev(struct xhci_hcd *xhci, u32 cap_offset)
 		return ret;
 	}
 
+	if (pci->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI) {
+		ret = platform_device_add_properties(pdev, role_switch_props);
+		if (ret) {
+			dev_err(dev, "failed to register device properties\n");
+			return ret;
+		}
+	}
+
 	pdev->dev.parent = dev;
 
 	ret = platform_device_add(pdev);
-- 
1.9.1

[PATCH v4 2/2] usb: roles: intel: Enable static DRD mode for role switch

[Saranya Gopal]

Enable static DRD mode in Intel platforms which guarantees
successful role switch all the time. This fixes issues like
software role switch failure after cold boot and issue with
role switch when USB 3.0 cable is used. But, do not enable
static DRD mode for Cherrytrail devices which rely on firmware
for role switch.

Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>
Signed-off-by: Balaji Manoharan <m.balaji@intel.com>
---
 changes since v3: Initialized drd_config variable to fix warning
 changes since v2: Revised SoB tags
 changes since v1: Added drd_config to avoid multiple if checks
                   Other minor changes suggested by Hans
                   
 drivers/usb/roles/intel-xhci-usb-role-switch.c | 27 ++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/roles/intel-xhci-usb-role-switch.c b/drivers/usb/roles/intel-xhci-usb-role-switch.c
index 277de96..88d0416 100644
--- a/drivers/usb/roles/intel-xhci-usb-role-switch.c
+++ b/drivers/usb/roles/intel-xhci-usb-role-switch.c
@@ -19,6 +19,7 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/property.h>
 #include <linux/usb/role.h>
 
 /* register definition */
@@ -26,6 +27,12 @@
 #define SW_VBUS_VALID			BIT(24)
 #define SW_IDPIN_EN			BIT(21)
 #define SW_IDPIN			BIT(20)
+#define SW_SWITCH_EN			BIT(16)
+
+#define DRD_CONFIG_DYNAMIC		0
+#define DRD_CONFIG_STATIC_HOST		1
+#define DRD_CONFIG_STATIC_DEVICE	2
+#define DRD_CONFIG_MASK			3
 
 #define DUAL_ROLE_CFG1			0x6c
 #define HOST_MODE			BIT(29)
@@ -37,6 +44,7 @@
 struct intel_xhci_usb_data {
 	struct usb_role_switch *role_sw;
 	void __iomem *base;
+	bool enable_sw_switch;
 };
 
 static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
@@ -45,6 +53,7 @@ static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
 	unsigned long timeout;
 	acpi_status status;
 	u32 glk, val;
+	u32 drd_config = DRD_CONFIG_DYNAMIC;
 
 	/*
 	 * On many CHT devices ACPI event (_AEI) handlers read / modify /
@@ -59,24 +68,35 @@ static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
 
 	pm_runtime_get_sync(dev);
 
-	/* Set idpin value as requested */
+	/*
+	 * Set idpin value as requested.
+	 * Since some devices rely on firmware setting DRD_CONFIG and
+	 * SW_SWITCH_EN bits to be zero for role switch,
+	 * do not set these bits for those devices.
+	 */
 	val = readl(data->base + DUAL_ROLE_CFG0);
 	switch (role) {
 	case USB_ROLE_NONE:
 		val |= SW_IDPIN;
 		val &= ~SW_VBUS_VALID;
+		drd_config = DRD_CONFIG_DYNAMIC;
 		break;
 	case USB_ROLE_HOST:
 		val &= ~SW_IDPIN;
 		val &= ~SW_VBUS_VALID;
+		drd_config = DRD_CONFIG_STATIC_HOST;
 		break;
 	case USB_ROLE_DEVICE:
 		val |= SW_IDPIN;
 		val |= SW_VBUS_VALID;
+		drd_config = DRD_CONFIG_STATIC_DEVICE;
 		break;
 	}
 	val |= SW_IDPIN_EN;
-
+	if (data->enable_sw_switch) {
+		val &= ~DRD_CONFIG_MASK;
+		val |= SW_SWITCH_EN | drd_config;
+	}
 	writel(val, data->base + DUAL_ROLE_CFG0);
 
 	acpi_release_global_lock(glk);
@@ -147,6 +167,9 @@ static int intel_xhci_usb_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, data);
 
+	data->enable_sw_switch = !device_property_read_bool(dev,
+						"sw_switch_disable");
+
 	data->role_sw = usb_role_switch_register(dev, &sw_desc);
 	if (IS_ERR(data->role_sw))
 		return PTR_ERR(data->role_sw);
-- 
1.9.1

Re: [PATCH v4 1/2] xhci-ext-caps.c: Add property to disable Intel SW switch

[Heikki Krogerus]

On Thu, Aug 29, 2019 at 04:12:06PM +0530, Saranya Gopal wrote:
> In platforms like Cherrytrail, 'SW switch enable' bit
> should not be enabled for role switch. This patch
> adds a property to Intel USB Role Switch platform driver
> to denote that SW switch should be disabled in
> Cherrytrail devices.
> 
> Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>
> Signed-off-by: Balaji Manoharan <m.balaji@intel.com>
> Suggested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  changes since v3: none
>  changes since v2: Added suggested-by tag
>  changes since v1: none
> 
>  drivers/usb/host/xhci-ext-caps.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/usb/host/xhci-ext-caps.c b/drivers/usb/host/xhci-ext-caps.c
> index 399113f..f498160 100644
> --- a/drivers/usb/host/xhci-ext-caps.c
> +++ b/drivers/usb/host/xhci-ext-caps.c
> @@ -6,11 +6,20 @@
>   */
>  
>  #include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/pci.h>
>  #include "xhci.h"
>  
>  #define USB_SW_DRV_NAME		"intel_xhci_usb_sw"
>  #define USB_SW_RESOURCE_SIZE	0x400
>  
> +#define PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI	0x22b5
> +
> +static const struct property_entry role_switch_props[] = {
> +	PROPERTY_ENTRY_BOOL("sw_switch_disable"),
> +	{},
> +};
> +
>  static void xhci_intel_unregister_pdev(void *arg)
>  {
>  	platform_device_unregister(arg);
> @@ -21,6 +30,7 @@ static int xhci_create_intel_xhci_sw_pdev(struct xhci_hcd *xhci, u32 cap_offset)
>  	struct usb_hcd *hcd = xhci_to_hcd(xhci);
>  	struct device *dev = hcd->self.controller;
>  	struct platform_device *pdev;
> +	struct pci_dev *pci = to_pci_dev(dev);
>  	struct resource	res = { 0, };
>  	int ret;
>  
> @@ -43,6 +53,14 @@ static int xhci_create_intel_xhci_sw_pdev(struct xhci_hcd *xhci, u32 cap_offset)
>  		return ret;
>  	}
>  
> +	if (pci->device == PCI_DEVICE_ID_INTEL_CHERRYVIEW_XHCI) {
> +		ret = platform_device_add_properties(pdev, role_switch_props);
> +		if (ret) {
> +			dev_err(dev, "failed to register device properties\n");
> +			return ret;
> +		}
> +	}
> +
>  	pdev->dev.parent = dev;
>  
>  	ret = platform_device_add(pdev);
> -- 
> 1.9.1

thanks,

-- 
heikki

Re: [PATCH v4 2/2] usb: roles: intel: Enable static DRD mode for role switch

[Hans de Goede]

Hi Saranya,

On 29-08-19 12:42, Saranya Gopal wrote:
> Enable static DRD mode in Intel platforms which guarantees
> successful role switch all the time. This fixes issues like
> software role switch failure after cold boot and issue with
> role switch when USB 3.0 cable is used. But, do not enable
> static DRD mode for Cherrytrail devices which rely on firmware
> for role switch.
> 
> Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>
> Signed-off-by: Balaji Manoharan <m.balaji@intel.com>

Unfortunately this patch conflicts with a patch to
drivers/usb/roles/intel-xhci-usb-role-switch.c from Heikki
which is already in -next, see:

https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/log/?h=devprop

And specifically this commit:

https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commit/?h=devprop&id=d2a90ebb65536a6deeb9daf5aa8e0700e8cbb43a

So you need to rebase on op of that branch and then the subsys
maintainers need to figure out how to merge this, I guess
the usb-next tree can merge Rafael's devprop branch for this?

I've manually resolved the conflict locally and  given this new version
a test-run on a Cherry Trail device and things still work as they should
there, so with the conflict fixed this series is:

Tested-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans


> ---
>   changes since v3: Initialized drd_config variable to fix warning
>   changes since v2: Revised SoB tags
>   changes since v1: Added drd_config to avoid multiple if checks
>                     Other minor changes suggested by Hans
>                     
>   drivers/usb/roles/intel-xhci-usb-role-switch.c | 27 ++++++++++++++++++++++++--
>   1 file changed, 25 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/roles/intel-xhci-usb-role-switch.c b/drivers/usb/roles/intel-xhci-usb-role-switch.c
> index 277de96..88d0416 100644
> --- a/drivers/usb/roles/intel-xhci-usb-role-switch.c
> +++ b/drivers/usb/roles/intel-xhci-usb-role-switch.c
> @@ -19,6 +19,7 @@
>   #include <linux/module.h>
>   #include <linux/platform_device.h>
>   #include <linux/pm_runtime.h>
> +#include <linux/property.h>
>   #include <linux/usb/role.h>
>   
>   /* register definition */
> @@ -26,6 +27,12 @@
>   #define SW_VBUS_VALID			BIT(24)
>   #define SW_IDPIN_EN			BIT(21)
>   #define SW_IDPIN			BIT(20)
> +#define SW_SWITCH_EN			BIT(16)
> +
> +#define DRD_CONFIG_DYNAMIC		0
> +#define DRD_CONFIG_STATIC_HOST		1
> +#define DRD_CONFIG_STATIC_DEVICE	2
> +#define DRD_CONFIG_MASK			3
>   
>   #define DUAL_ROLE_CFG1			0x6c
>   #define HOST_MODE			BIT(29)
> @@ -37,6 +44,7 @@
>   struct intel_xhci_usb_data {
>   	struct usb_role_switch *role_sw;
>   	void __iomem *base;
> +	bool enable_sw_switch;
>   };
>   
>   static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
> @@ -45,6 +53,7 @@ static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
>   	unsigned long timeout;
>   	acpi_status status;
>   	u32 glk, val;
> +	u32 drd_config = DRD_CONFIG_DYNAMIC;
>   
>   	/*
>   	 * On many CHT devices ACPI event (_AEI) handlers read / modify /
> @@ -59,24 +68,35 @@ static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
>   
>   	pm_runtime_get_sync(dev);
>   
> -	/* Set idpin value as requested */
> +	/*
> +	 * Set idpin value as requested.
> +	 * Since some devices rely on firmware setting DRD_CONFIG and
> +	 * SW_SWITCH_EN bits to be zero for role switch,
> +	 * do not set these bits for those devices.
> +	 */
>   	val = readl(data->base + DUAL_ROLE_CFG0);
>   	switch (role) {
>   	case USB_ROLE_NONE:
>   		val |= SW_IDPIN;
>   		val &= ~SW_VBUS_VALID;
> +		drd_config = DRD_CONFIG_DYNAMIC;
>   		break;
>   	case USB_ROLE_HOST:
>   		val &= ~SW_IDPIN;
>   		val &= ~SW_VBUS_VALID;
> +		drd_config = DRD_CONFIG_STATIC_HOST;
>   		break;
>   	case USB_ROLE_DEVICE:
>   		val |= SW_IDPIN;
>   		val |= SW_VBUS_VALID;
> +		drd_config = DRD_CONFIG_STATIC_DEVICE;
>   		break;
>   	}
>   	val |= SW_IDPIN_EN;
> -
> +	if (data->enable_sw_switch) {
> +		val &= ~DRD_CONFIG_MASK;
> +		val |= SW_SWITCH_EN | drd_config;
> +	}
>   	writel(val, data->base + DUAL_ROLE_CFG0);
>   
>   	acpi_release_global_lock(glk);
> @@ -147,6 +167,9 @@ static int intel_xhci_usb_probe(struct platform_device *pdev)
>   
>   	platform_set_drvdata(pdev, data);
>   
> +	data->enable_sw_switch = !device_property_read_bool(dev,
> +						"sw_switch_disable");
> +
>   	data->role_sw = usb_role_switch_register(dev, &sw_desc);
>   	if (IS_ERR(data->role_sw))
>   		return PTR_ERR(data->role_sw);
> 

Re: [PATCH v4 2/2] usb: roles: intel: Enable static DRD mode for role switch

[Heikki Krogerus]

On Thu, Aug 29, 2019 at 04:12:07PM +0530, Saranya Gopal wrote:
> Enable static DRD mode in Intel platforms which guarantees
> successful role switch all the time. This fixes issues like
> software role switch failure after cold boot and issue with
> role switch when USB 3.0 cable is used. But, do not enable
> static DRD mode for Cherrytrail devices which rely on firmware
> for role switch.
> 
> Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>
> Signed-off-by: Balaji Manoharan <m.balaji@intel.com>

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

> ---
>  changes since v3: Initialized drd_config variable to fix warning
>  changes since v2: Revised SoB tags
>  changes since v1: Added drd_config to avoid multiple if checks
>                    Other minor changes suggested by Hans
>                    
>  drivers/usb/roles/intel-xhci-usb-role-switch.c | 27 ++++++++++++++++++++++++--
>  1 file changed, 25 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/roles/intel-xhci-usb-role-switch.c b/drivers/usb/roles/intel-xhci-usb-role-switch.c
> index 277de96..88d0416 100644
> --- a/drivers/usb/roles/intel-xhci-usb-role-switch.c
> +++ b/drivers/usb/roles/intel-xhci-usb-role-switch.c
> @@ -19,6 +19,7 @@
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/property.h>
>  #include <linux/usb/role.h>
>  
>  /* register definition */
> @@ -26,6 +27,12 @@
>  #define SW_VBUS_VALID			BIT(24)
>  #define SW_IDPIN_EN			BIT(21)
>  #define SW_IDPIN			BIT(20)
> +#define SW_SWITCH_EN			BIT(16)
> +
> +#define DRD_CONFIG_DYNAMIC		0
> +#define DRD_CONFIG_STATIC_HOST		1
> +#define DRD_CONFIG_STATIC_DEVICE	2
> +#define DRD_CONFIG_MASK			3
>  
>  #define DUAL_ROLE_CFG1			0x6c
>  #define HOST_MODE			BIT(29)
> @@ -37,6 +44,7 @@
>  struct intel_xhci_usb_data {
>  	struct usb_role_switch *role_sw;
>  	void __iomem *base;
> +	bool enable_sw_switch;
>  };
>  
>  static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
> @@ -45,6 +53,7 @@ static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
>  	unsigned long timeout;
>  	acpi_status status;
>  	u32 glk, val;
> +	u32 drd_config = DRD_CONFIG_DYNAMIC;
>  
>  	/*
>  	 * On many CHT devices ACPI event (_AEI) handlers read / modify /
> @@ -59,24 +68,35 @@ static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
>  
>  	pm_runtime_get_sync(dev);
>  
> -	/* Set idpin value as requested */
> +	/*
> +	 * Set idpin value as requested.
> +	 * Since some devices rely on firmware setting DRD_CONFIG and
> +	 * SW_SWITCH_EN bits to be zero for role switch,
> +	 * do not set these bits for those devices.
> +	 */
>  	val = readl(data->base + DUAL_ROLE_CFG0);
>  	switch (role) {
>  	case USB_ROLE_NONE:
>  		val |= SW_IDPIN;
>  		val &= ~SW_VBUS_VALID;
> +		drd_config = DRD_CONFIG_DYNAMIC;
>  		break;
>  	case USB_ROLE_HOST:
>  		val &= ~SW_IDPIN;
>  		val &= ~SW_VBUS_VALID;
> +		drd_config = DRD_CONFIG_STATIC_HOST;
>  		break;
>  	case USB_ROLE_DEVICE:
>  		val |= SW_IDPIN;
>  		val |= SW_VBUS_VALID;
> +		drd_config = DRD_CONFIG_STATIC_DEVICE;
>  		break;
>  	}
>  	val |= SW_IDPIN_EN;
> -
> +	if (data->enable_sw_switch) {
> +		val &= ~DRD_CONFIG_MASK;
> +		val |= SW_SWITCH_EN | drd_config;
> +	}
>  	writel(val, data->base + DUAL_ROLE_CFG0);
>  
>  	acpi_release_global_lock(glk);
> @@ -147,6 +167,9 @@ static int intel_xhci_usb_probe(struct platform_device *pdev)
>  
>  	platform_set_drvdata(pdev, data);
>  
> +	data->enable_sw_switch = !device_property_read_bool(dev,
> +						"sw_switch_disable");
> +
>  	data->role_sw = usb_role_switch_register(dev, &sw_desc);
>  	if (IS_ERR(data->role_sw))
>  		return PTR_ERR(data->role_sw);
> -- 
> 1.9.1

thanks,

-- 
heikki

RE: [PATCH v4 2/2] usb: roles: intel: Enable static DRD mode for role switch

[Gopal, Saranya]

> -----Original Message-----
> From: linux-usb-owner@vger.kernel.org [mailto:linux-usb-
> owner@vger.kernel.org] On Behalf Of Hans de Goede
> Sent: Thursday, August 29, 2019 4:34 PM
> To: Gopal, Saranya <saranya.gopal@intel.com>;
> heikki.krogerus@linux.intel.com
> Cc: gregkh@linuxfoundation.org; Nyman, Mathias
> <mathias.nyman@intel.com>; linux-usb@vger.kernel.org; Balaji, M
> <m.balaji@intel.com>; Rafał Psota <rafalzaq@gmail.com>; Rafael J. Wysocki
> <rjw@rjwysocki.net>
> Subject: Re: [PATCH v4 2/2] usb: roles: intel: Enable static DRD mode for role
> switch
> 
> Hi Saranya,
> 
> On 29-08-19 12:42, Saranya Gopal wrote:
> > Enable static DRD mode in Intel platforms which guarantees
> > successful role switch all the time. This fixes issues like
> > software role switch failure after cold boot and issue with
> > role switch when USB 3.0 cable is used. But, do not enable
> > static DRD mode for Cherrytrail devices which rely on firmware
> > for role switch.
> >
> > Signed-off-by: Saranya Gopal <saranya.gopal@intel.com>
> > Signed-off-by: Balaji Manoharan <m.balaji@intel.com>
> 
> Unfortunately this patch conflicts with a patch to
> drivers/usb/roles/intel-xhci-usb-role-switch.c from Heikki
> which is already in -next, see:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-
> pm.git/log/?h=devprop
> 
> And specifically this commit:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-
> pm.git/commit/?h=devprop&id=d2a90ebb65536a6deeb9daf5aa8e0700e8cbb43
> a
> 
> So you need to rebase on op of that branch and then the subsys
> maintainers need to figure out how to merge this, I guess
> the usb-next tree can merge Rafael's devprop branch for this?
>
Sure, let me rebase on top of that branch.
Thanks,
Saranya
 
> I've manually resolved the conflict locally and  given this new version
> a test-run on a Cherry Trail device and things still work as they should
> there, so with the conflict fixed this series is:
> 
> Tested-by: Hans de Goede <hdegoede@redhat.com>
> Reviewed-by: Hans de Goede <hdegoede@redhat.com>
> 
> Regards,
> 
> Hans
> 
> 
> > ---
> >   changes since v3: Initialized drd_config variable to fix warning
> >   changes since v2: Revised SoB tags
> >   changes since v1: Added drd_config to avoid multiple if checks
> >                     Other minor changes suggested by Hans
> >
> >   drivers/usb/roles/intel-xhci-usb-role-switch.c | 27
> ++++++++++++++++++++++++--
> >   1 file changed, 25 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/roles/intel-xhci-usb-role-switch.c
> b/drivers/usb/roles/intel-xhci-usb-role-switch.c
> > index 277de96..88d0416 100644
> > --- a/drivers/usb/roles/intel-xhci-usb-role-switch.c
> > +++ b/drivers/usb/roles/intel-xhci-usb-role-switch.c
> > @@ -19,6 +19,7 @@
> >   #include <linux/module.h>
> >   #include <linux/platform_device.h>
> >   #include <linux/pm_runtime.h>
> > +#include <linux/property.h>
> >   #include <linux/usb/role.h>
> >
> >   /* register definition */
> > @@ -26,6 +27,12 @@
> >   #define SW_VBUS_VALID			BIT(24)
> >   #define SW_IDPIN_EN			BIT(21)
> >   #define SW_IDPIN			BIT(20)
> > +#define SW_SWITCH_EN			BIT(16)
> > +
> > +#define DRD_CONFIG_DYNAMIC		0
> > +#define DRD_CONFIG_STATIC_HOST		1
> > +#define DRD_CONFIG_STATIC_DEVICE	2
> > +#define DRD_CONFIG_MASK			3
> >
> >   #define DUAL_ROLE_CFG1			0x6c
> >   #define HOST_MODE			BIT(29)
> > @@ -37,6 +44,7 @@
> >   struct intel_xhci_usb_data {
> >   	struct usb_role_switch *role_sw;
> >   	void __iomem *base;
> > +	bool enable_sw_switch;
> >   };
> >
> >   static int intel_xhci_usb_set_role(struct device *dev, enum usb_role role)
> > @@ -45,6 +53,7 @@ static int intel_xhci_usb_set_role(struct device *dev,
> enum usb_role role)
> >   	unsigned long timeout;
> >   	acpi_status status;
> >   	u32 glk, val;
> > +	u32 drd_config = DRD_CONFIG_DYNAMIC;
> >
> >   	/*
> >   	 * On many CHT devices ACPI event (_AEI) handlers read / modify /
> > @@ -59,24 +68,35 @@ static int intel_xhci_usb_set_role(struct device *dev,
> enum usb_role role)
> >
> >   	pm_runtime_get_sync(dev);
> >
> > -	/* Set idpin value as requested */
> > +	/*
> > +	 * Set idpin value as requested.
> > +	 * Since some devices rely on firmware setting DRD_CONFIG and
> > +	 * SW_SWITCH_EN bits to be zero for role switch,
> > +	 * do not set these bits for those devices.
> > +	 */
> >   	val = readl(data->base + DUAL_ROLE_CFG0);
> >   	switch (role) {
> >   	case USB_ROLE_NONE:
> >   		val |= SW_IDPIN;
> >   		val &= ~SW_VBUS_VALID;
> > +		drd_config = DRD_CONFIG_DYNAMIC;
> >   		break;
> >   	case USB_ROLE_HOST:
> >   		val &= ~SW_IDPIN;
> >   		val &= ~SW_VBUS_VALID;
> > +		drd_config = DRD_CONFIG_STATIC_HOST;
> >   		break;
> >   	case USB_ROLE_DEVICE:
> >   		val |= SW_IDPIN;
> >   		val |= SW_VBUS_VALID;
> > +		drd_config = DRD_CONFIG_STATIC_DEVICE;
> >   		break;
> >   	}
> >   	val |= SW_IDPIN_EN;
> > -
> > +	if (data->enable_sw_switch) {
> > +		val &= ~DRD_CONFIG_MASK;
> > +		val |= SW_SWITCH_EN | drd_config;
> > +	}
> >   	writel(val, data->base + DUAL_ROLE_CFG0);
> >
> >   	acpi_release_global_lock(glk);
> > @@ -147,6 +167,9 @@ static int intel_xhci_usb_probe(struct platform_device
> *pdev)
> >
> >   	platform_set_drvdata(pdev, data);
> >
> > +	data->enable_sw_switch = !device_property_read_bool(dev,
> > +						"sw_switch_disable");
> > +
> >   	data->role_sw = usb_role_switch_register(dev, &sw_desc);
> >   	if (IS_ERR(data->role_sw))
> >   		return PTR_ERR(data->role_sw);
> >