According to the "Enhanced Host Controller Interface Specification for
Universal Serial Bus" after a USB port reset the EHCI Driver checks the
PortEnable bit in the PORTSC register. If set to a one, the connected device is
a high-speed device [...]. At the time the EHCI Driver receives the port reset
and enable request the LineStatus bits might indicate a low-speed device.
Additionally, when the port reset process is complete, the PortEnable field may
indicate that a full-speed device is attached. In either case the EHCI driver
sets the PortOwner bit in the PORTSC register to a one to release port
ownership to a companion host controller.
Signed-off-by: Peter Mamonov <pmamonov@xxxxxxxxx>
---
drivers/usb/host/ehci-hcd.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 79bf4fb9d..d0be2104d 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -477,6 +477,18 @@ static inline void ehci_powerup_fixup(struct ehci_priv *ehci)
}
#endif
+static void pass_to_companion(struct ehci_priv *ehci, int port)
+{
+ uint32_t *status_reg = (uint32_t *)&ehci->hcor->or_portsc[port - 1];
+ uint32_t reg = ehci_readl(status_reg);
+
+ reg &= ~EHCI_PS_CLEAR;
+ dev_dbg(ehci->dev, "port %d --> companion\n",
+ port - 1);
+ reg |= EHCI_PS_PO;
+ ehci_writel(status_reg, reg);
+}
+
static int
ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
int length, struct devrequest *req)
@@ -509,6 +521,10 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
return -1;
}
status_reg = (uint32_t *)&ehci->hcor->or_portsc[port - 1];
+ if (ehci_readl(status_reg) & EHCI_PS_PO) {
+ dev_dbg(ehci->dev, "Port %d is owned by companion controller\n", port);
+ return -1;
+ }
break;
default:
status_reg = NULL;
@@ -655,11 +671,7 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
if ((reg & (EHCI_PS_PE | EHCI_PS_CS)) == EHCI_PS_CS &&
!ehci_is_TDI() &&
EHCI_PS_IS_LOWSPEED(reg)) {
- /* Low speed device, give up ownership. */
- dev_dbg(ehci->dev, "port %d low speed --> companion\n",
- port - 1);
- reg |= EHCI_PS_PO;
- ehci_writel(status_reg, reg);
+ pass_to_companion(ehci, port);
break;
} else {
int ret;
@@ -690,7 +702,10 @@ ehci_submit_root(struct usb_device *dev, unsigned long pipe, void *buffer,
else
dev_err(ehci->dev, "port(%d) reset error\n",
port - 1);
-
+ mdelay(200);
+ reg = ehci_readl(status_reg);
+ if (!(reg & EHCI_PS_PE))
+ pass_to_companion(ehci, port);
}
break;
default:
--
2.11.0
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