diff options
| author | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2014-01-31 11:52:57 -0800 |
|---|---|---|
| committer | Sarah Sharp <sarah.a.sharp@linux.intel.com> | 2014-02-07 14:30:03 -0800 |
| commit | 3d4b81eda2211f32886e2978daf6f39885042fc4 (patch) | |
| tree | a5eaedd2afe98eebb2268f67640f44530992f707 | |
| parent | 9cf00d91708221ff2d8a11143315f7ebab8d5da8 (diff) | |
Revert "usb: xhci: Link TRB must not occur within a USB payload burst"
This reverts commit 35773dac5f862cb1c82ea151eba3e2f6de51ec3e. It's a
hack that caused regressions in the usb-storage and userspace USB
drivers that use usbfs and libusb. Commit 70cabb7d992f "xhci 1.0: Limit
arbitrarily-aligned scatter gather." should fix the issues seen with the
ax88179_178a driver on xHCI 1.0 hosts, without causing regressions.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org # 3.12
| -rw-r--r-- | drivers/usb/host/xhci-ring.c | 54 | ||||
| -rw-r--r-- | include/linux/usb.h | 2 |
2 files changed, 2 insertions, 54 deletions
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 0272450a166..0ed64eb68e4 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2967,58 +2967,8 @@ static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring, } while (1) { - if (room_on_ring(xhci, ep_ring, num_trbs)) { - union xhci_trb *trb = ep_ring->enqueue; - unsigned int usable = ep_ring->enq_seg->trbs + - TRBS_PER_SEGMENT - 1 - trb; - u32 nop_cmd; - - /* - * Section 4.11.7.1 TD Fragments states that a link - * TRB must only occur at the boundary between - * data bursts (eg 512 bytes for 480M). - * While it is possible to split a large fragment - * we don't know the size yet. - * Simplest solution is to fill the trb before the - * LINK with nop commands. - */ - if (num_trbs == 1 || num_trbs <= usable || usable == 0) - break; - - if (ep_ring->type != TYPE_BULK) - /* - * While isoc transfers might have a buffer that - * crosses a 64k boundary it is unlikely. - * Since we can't add NOPs without generating - * gaps in the traffic just hope it never - * happens at the end of the ring. - * This could be fixed by writing a LINK TRB - * instead of the first NOP - however the - * TRB_TYPE_LINK_LE32() calls would all need - * changing to check the ring length. - */ - break; - - if (num_trbs >= TRBS_PER_SEGMENT) { - xhci_err(xhci, "Too many fragments %d, max %d\n", - num_trbs, TRBS_PER_SEGMENT - 1); - return -ENOMEM; - } - - nop_cmd = cpu_to_le32(TRB_TYPE(TRB_TR_NOOP) | - ep_ring->cycle_state); - ep_ring->num_trbs_free -= usable; - do { - trb->generic.field[0] = 0; - trb->generic.field[1] = 0; - trb->generic.field[2] = 0; - trb->generic.field[3] = nop_cmd; - trb++; - } while (--usable); - ep_ring->enqueue = trb; - if (room_on_ring(xhci, ep_ring, num_trbs)) - break; - } + if (room_on_ring(xhci, ep_ring, num_trbs)) + break; if (ep_ring == xhci->cmd_ring) { xhci_err(xhci, "Do not support expand command ring\n"); diff --git a/include/linux/usb.h b/include/linux/usb.h index c716da18c66..7f6eb859873 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1265,8 +1265,6 @@ typedef void (*usb_complete_t)(struct urb *); * @sg: scatter gather buffer list, the buffer size of each element in * the list (except the last) must be divisible by the endpoint's * max packet size if no_sg_constraint isn't set in 'struct usb_bus' - * (FIXME: scatter-gather under xHCI is broken for periodic transfers. - * Do not use urb->sg for interrupt endpoints for now, only bulk.) * @num_mapped_sgs: (internal) number of mapped sg entries * @num_sgs: number of entries in the sg list * @transfer_buffer_length: How big is transfer_buffer. The transfer may |