diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2013-12-05 17:07:27 -0800 |
|---|---|---|
| committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2013-12-10 13:54:37 -0800 |
| commit | 48fc7dbd52c0559647291f33a10ccdc6cdbe4c72 (patch) | |
| tree | 4a2403420a69b2d40e38a53302771ec3d3eb6b66 /drivers/usb/host/xhci-ring.c | |
| parent | 40fcd88b8d49fd911518190c985112097d3a8a17 (diff) | |
| download | linux-48fc7dbd52c0559647291f33a10ccdc6cdbe4c72.tar.gz | |
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>
Diffstat (limited to 'drivers/usb/host/xhci-ring.c')
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 6 |
1 files changed, 3 insertions, 3 deletions
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, |