When combining dwc3 with an redriver for a USB Type-C device solution, it
sometimes have problems with leaving U1/U2 for certain hosts, resulting in
link training errors and reconnects. This create an interface via
configfs for disabling U1/U2, enabling a workaround for devices based on
dwc3.
Signed-off-by: Claus H. Stovgaard <cst@xxxxxxxxxxxx>
---
drivers/usb/dwc3/ep0.c | 9 ++++++-
drivers/usb/gadget/configfs.c | 56 +++++++++++++++++++++++++++++++++++++++++++
include/linux/usb/gadget.h | 6 ++++-
3 files changed, 69 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 8efde17..5b2d26b 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -379,6 +379,8 @@ static int dwc3_ep0_handle_u1(struct dwc3 *dwc, enum usb_device_state state,
if ((dwc->speed != DWC3_DSTS_SUPERSPEED) &&
(dwc->speed != DWC3_DSTS_SUPERSPEED_PLUS))
return -EINVAL;
+ if (dwc->gadget_driver->lpm_U1_disable)
+ return -EINVAL;
reg = dwc3_readl(dwc->regs, DWC3_DCTL);
if (set)
@@ -401,6 +403,8 @@ static int dwc3_ep0_handle_u2(struct dwc3 *dwc, enum usb_device_state state,
if ((dwc->speed != DWC3_DSTS_SUPERSPEED) &&
(dwc->speed != DWC3_DSTS_SUPERSPEED_PLUS))
return -EINVAL;
+ if (dwc->gadget_driver->lpm_U2_disable)
+ return -EINVAL;
reg = dwc3_readl(dwc->regs, DWC3_DCTL);
if (set)
@@ -626,7 +630,10 @@ static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
* nothing is pending from application.
*/
reg = dwc3_readl(dwc->regs, DWC3_DCTL);
- reg |= (DWC3_DCTL_ACCEPTU1ENA | DWC3_DCTL_ACCEPTU2ENA);
+ if (!dwc->gadget_driver->lpm_U1_disable)
+ reg |= DWC3_DCTL_ACCEPTU1ENA;
+ if (!dwc->gadget_driver->lpm_U2_disable)
+ reg |= DWC3_DCTL_ACCEPTU2ENA;
dwc3_writel(dwc->regs, DWC3_DCTL, reg);
}
break;
diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c
index 0251299..2ee9d10 100644
--- a/drivers/usb/gadget/configfs.c
+++ b/drivers/usb/gadget/configfs.c
@@ -229,6 +229,56 @@ static ssize_t gadget_dev_desc_bcdUSB_store(struct config_item *item,
return len;
}
+static ssize_t gadget_dev_desc_lpm_U1_disable_show(struct config_item *item,
+ char *page)
+{
+ struct gadget_info *gi = to_gadget_info(item);
+
+ return sprintf(page, "%d\n",
+ gi->composite.gadget_driver.lpm_U1_disable);
+}
+
+static ssize_t gadget_dev_desc_lpm_U1_disable_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct gadget_info *gi = to_gadget_info(item);
+ bool disable;
+ int ret;
+
+ ret = strtobool(page, &disable);
+ if (!ret) {
+ gi->composite.gadget_driver.lpm_U1_disable = disable;
+ ret = len;
+ }
+
+ return ret;
+}
+
+static ssize_t gadget_dev_desc_lpm_U2_disable_show(struct config_item *item,
+ char *page)
+{
+ struct gadget_info *gi = to_gadget_info(item);
+
+ return sprintf(page, "%d\n",
+ gi->composite.gadget_driver.lpm_U2_disable);
+}
+
+static ssize_t gadget_dev_desc_lpm_U2_disable_store(struct config_item *item,
+ const char *page, size_t len)
+{
+ struct gadget_info *gi = to_gadget_info(item);
+ bool disable;
+ int ret;
+
+ ret = strtobool(page, &disable);
+ if (!ret) {
+ gi->composite.gadget_driver.lpm_U2_disable = disable;
+ ret = len;
+ }
+
+ return ret;
+}
+
static ssize_t gadget_dev_desc_UDC_show(struct config_item *item, char *page)
{
char *udc_name = to_gadget_info(item)->composite.gadget_driver.udc_name;
@@ -299,6 +349,8 @@ CONFIGFS_ATTR(gadget_dev_desc_, idVendor);
CONFIGFS_ATTR(gadget_dev_desc_, idProduct);
CONFIGFS_ATTR(gadget_dev_desc_, bcdDevice);
CONFIGFS_ATTR(gadget_dev_desc_, bcdUSB);
+CONFIGFS_ATTR(gadget_dev_desc_, lpm_U1_disable);
+CONFIGFS_ATTR(gadget_dev_desc_, lpm_U2_disable);
CONFIGFS_ATTR(gadget_dev_desc_, UDC);
static struct configfs_attribute *gadget_root_attrs[] = {
@@ -310,6 +362,8 @@ static struct configfs_attribute *gadget_root_attrs[] = {
&gadget_dev_desc_attr_idProduct,
&gadget_dev_desc_attr_bcdDevice,
&gadget_dev_desc_attr_bcdUSB,
+ &gadget_dev_desc_attr_lpm_U1_disable,
+ &gadget_dev_desc_attr_lpm_U2_disable,
&gadget_dev_desc_attr_UDC,
NULL,
};
@@ -1408,6 +1462,8 @@ static const struct usb_gadget_driver configfs_driver_template = {
.name = "configfs-gadget",
},
.match_existing_only = 1,
+ .lpm_U1_disable = 0,
+ .lpm_U2_disable = 0,
};
static struct config_group *gadgets_make(
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 7595056..25fe72b 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -619,7 +619,9 @@ static inline int usb_gadget_activate(struct usb_gadget *gadget)
* this driver will be bound to any available UDC.
* @pending: UDC core private data used for deferred probe of this driver.
* @match_existing_only: If udc is not found, return an error and don't add this
- * gadget driver to list of pending driver
+ * gadget driver to list of pending driver.
+ * @lpm_U1_disable: Instruct the UDC to disable U1 if possible.
+ * @lpm_U2_disable: Instruct the UDC to disable U2 if possible.
*
* Devices are disabled till a gadget driver successfully bind()s, which
* means the driver will handle setup() requests needed to enumerate (and
@@ -684,6 +686,8 @@ struct usb_gadget_driver {
char *udc_name;
struct list_head pending;
unsigned match_existing_only:1;
+ unsigned lpm_U1_disable:1;
+ unsigned lpm_U2_disable:1;
};
--
2.7.4
