usb: xhci: change enumeration scheme to 'new scheme' by default

Change the default enumeration scheme for xhci attached non-SuperSpeed
devices from:

   Reset
   SetAddress [xhci address-device BSR = 0]
   GetDescriptor(8)
   GetDescriptor(18)

...to:

   Reset
   [xhci address-device BSR = 1]
   GetDescriptor(64)
   Reset
   SetAddress [xhci address-device BSR = 0]
   GetDescriptor(18)

...as some devices misbehave when encountering a SetAddress command
prior to GetDescriptor.  There are known legacy devices that require
this scheme, but testing has found at least one USB3 device that fails
enumeration when presented with this ordering.  For now, follow the ehci
case and enable 'new scheme' by default for non-SuperSpeed devices.

To support this enumeration scheme on xhci the AddressDevice operation
needs to be performed twice.  The first instance of the command enables
the HC's device and slot context info for the device, but omits sending
the device a SetAddress command (BSR == block set address request).
Then, after GetDescriptor completes, follow up with the full
AddressDevice+SetAddress operation.

As mentioned before, this ordering of events with USB3 devices causes an
extra state transition to be exposed to xhci.  Previously USB3 devices
would transition directly from 'enabled' to 'addressed' and never need
to underrun responses to 'get descriptor'. We do see the 64-byte
descriptor fetch the correct data, but the following 18-byte descriptor
read after the reset gets:

bLength            = 0
bDescriptorType    = 0
bcdUSB             = 0
bDeviceClass       = 0
bDeviceSubClass    = 0
bDeviceProtocol    = 0
bMaxPacketSize0    = 9

instead of:

bLength            = 12
bDescriptorType    = 1
bcdUSB             = 300
bDeviceClass       = 0
bDeviceSubClass    = 0
bDeviceProtocol    = 0
bMaxPacketSize0    = 9

which results in the discovery process looping until falling back to
'old scheme' enumeration.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: David Moore <david.moore@gmail.com>
Suggested-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

5 files changed, 30 insertions, 8 deletions

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index b8dffd59eb25..4221dee924b5 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -331,6 +331,7 @@ static const struct hc_driver xhci_pci_hc_driver = {
 	.check_bandwidth =	xhci_check_bandwidth,
 	.reset_bandwidth =	xhci_reset_bandwidth,
 	.address_device =	xhci_address_device,
+	.enable_device =	xhci_enable_device,
 	.update_hub_device =	xhci_update_hub_device,
 	.reset_device =		xhci_discover_or_reset_device,
 
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 9d29aa1b1bc8..8abda5c73ca1 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -69,6 +69,7 @@ static const struct hc_driver xhci_plat_xhci_driver = {
 	.check_bandwidth =	xhci_check_bandwidth,
 	.reset_bandwidth =	xhci_reset_bandwidth,
 	.address_device =	xhci_address_device,
+	.enable_device =	xhci_enable_device,
 	.update_hub_device =	xhci_update_hub_device,
 	.reset_device =		xhci_discover_or_reset_device,
 
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index fe9208a5d103..d26cd9474aa6 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -4004,12 +4004,12 @@ int xhci_queue_slot_control(struct xhci_hcd *xhci, u32 trb_type, u32 slot_id)
 
 /* Queue an address device command TRB */
 int xhci_queue_address_device(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
-		u32 slot_id)
+			      u32 slot_id, enum xhci_setup_dev setup)
 {
 	return queue_command(xhci, lower_32_bits(in_ctx_ptr),
 			upper_32_bits(in_ctx_ptr), 0,
-			TRB_TYPE(TRB_ADDR_DEV) | SLOT_ID_FOR_TRB(slot_id),
-			false);
+			TRB_TYPE(TRB_ADDR_DEV) | SLOT_ID_FOR_TRB(slot_id)
+			| (setup == SETUP_CONTEXT_ONLY ? TRB_BSR : 0), false);
 }
 
 int xhci_queue_vendor_command(struct xhci_hcd *xhci,
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 7fe6f664054f..6598f7ee7938 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -3709,12 +3709,13 @@ disable_slot:
 }
 
 /*
- * Issue an Address Device command (which will issue a SetAddress request to
- * the device).
+ * Issue an Address Device command and optionally send a corresponding
+ * SetAddress request to the device.
  * We should be protected by the usb_address0_mutex in khubd's hub_port_init, so
  * we should only issue and wait on one address command at the same time.
  */
-int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
+static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
+			     enum xhci_setup_dev setup)
 {
 	unsigned long flags;
 	int timeleft;
@@ -3773,7 +3774,7 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
 	spin_lock_irqsave(&xhci->lock, flags);
 	cmd_trb = xhci_find_next_enqueue(xhci->cmd_ring);
 	ret = xhci_queue_address_device(xhci, virt_dev->in_ctx->dma,
-					udev->slot_id);
+					udev->slot_id, setup);
 	if (ret) {
 		spin_unlock_irqrestore(&xhci->lock, flags);
 		xhci_dbg_trace(xhci, trace_xhci_dbg_address,
@@ -3868,6 +3869,16 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
 	return 0;
 }
 
+int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+	return xhci_setup_device(hcd, udev, SETUP_CONTEXT_ADDRESS);
+}
+
+int xhci_enable_device(struct usb_hcd *hcd, struct usb_device *udev)
+{
+	return xhci_setup_device(hcd, udev, SETUP_CONTEXT_ONLY);
+}
+
 /*
  * Transfer the port index into real index in the HW port status
  * registers. Caculate offset between the port's PORTSC register
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 7807f621a713..24344aab2107 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1108,6 +1108,14 @@ struct xhci_event_cmd {
 };
 
 /* flags bitmasks */
+
+/* Address device - disable SetAddress */
+#define TRB_BSR		(1<<9)
+enum xhci_setup_dev {
+	SETUP_CONTEXT_ONLY,
+	SETUP_CONTEXT_ADDRESS,
+};
+
 /* bits 16:23 are the virtual function ID */
 /* bits 24:31 are the slot ID */
 #define TRB_TO_SLOT_ID(p)	(((p) & (0xff<<24)) >> 24)
@@ -1760,6 +1768,7 @@ int xhci_free_streams(struct usb_hcd *hcd, struct usb_device *udev,
 		struct usb_host_endpoint **eps, unsigned int num_eps,
 		gfp_t mem_flags);
 int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev);
+int xhci_enable_device(struct usb_hcd *hcd, struct usb_device *udev);
 int xhci_update_device(struct usb_hcd *hcd, struct usb_device *udev);
 int xhci_set_usb2_hardware_lpm(struct usb_hcd *hcd,
 				struct usb_device *udev, int enable);
@@ -1783,7 +1792,7 @@ int xhci_is_vendor_info_code(struct xhci_hcd *xhci, unsigned int trb_comp_code);
 void xhci_ring_cmd_db(struct xhci_hcd *xhci);
 int xhci_queue_slot_control(struct xhci_hcd *xhci, u32 trb_type, u32 slot_id);
 int xhci_queue_address_device(struct xhci_hcd *xhci, dma_addr_t in_ctx_ptr,
-		u32 slot_id);
+		u32 slot_id, enum xhci_setup_dev);
 int xhci_queue_vendor_command(struct xhci_hcd *xhci,
 		u32 field1, u32 field2, u32 field3, u32 field4);
 int xhci_queue_stop_endpoint(struct xhci_hcd *xhci, int slot_id,