iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

xhci: introduce a new move_dequeue_past_td() function to replace old code.

Browse Source 
Replace xhci_find_new_dequeue_state() and xhci_queue_new_dequeue_state()
functions with one combined function.
These function were always called after each other, and had a lot of extra
code just to pass the newly found dequeue state from the first function
to the other.

The new function also returns error in case there is a failure to
queue the new dequeue state. This way the caller can decide on
recovery measures to handle it.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20210129130044.206855-25-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman 2021-01-29 15:00:41 +02:00 committed by Greg Kroah-Hartman
parent 1174d44906
commit d1dbfb942c
1 changed files with 145 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

152
drivers/usb/host/xhci-ring.c
View File

@ -59,6 +59,10 @@
#include "xhci-trace.h"
#include "xhci-mtk.h"
static int queue_command(struct xhci_hcd *xhci, struct xhci_command *cmd,
u32 field1, u32 field2,
u32 field3, u32 field4, bool command_must_succeed);
/*
* Returns zero if the TRB isn't in this segment, otherwise it returns the DMA
* address of the TRB.
@ -664,6 +668,136 @@ done:
(unsigned long long) addr);
}
static int xhci_move_dequeue_past_td(struct xhci_hcd *xhci,
unsigned int slot_id, unsigned int ep_index,
unsigned int stream_id, struct xhci_td *td)
{
struct xhci_virt_device *dev = xhci->devs[slot_id];
struct xhci_virt_ep *ep = &dev->eps[ep_index];
struct xhci_ring *ep_ring;
struct xhci_command *cmd;
struct xhci_segment *new_seg;
union xhci_trb *new_deq;
int new_cycle;
dma_addr_t addr;
u64 hw_dequeue;
bool cycle_found = false;
bool td_last_trb_found = false;
u32 trb_sct = 0;
int ret;
ep_ring = xhci_triad_to_transfer_ring(xhci, slot_id,
ep_index, stream_id);
if (!ep_ring) {
xhci_warn(xhci, "WARN can't find new dequeue, invalid stream ID %u\n",
stream_id);
return -ENODEV;
}
/*
* A cancelled TD can complete with a stall if HW cached the trb.
* In this case driver can't find td, but if the ring is empty we
* can move the dequeue pointer to the current enqueue position.
* We shouldn't hit this anymore as cached cancelled TRBs are given back
* after clearing the cache, but be on the safe side and keep it anyway
*/
if (!td) {
if (list_empty(&ep_ring->td_list)) {
new_seg = ep_ring->enq_seg;
new_deq = ep_ring->enqueue;
new_cycle = ep_ring->cycle_state;
xhci_dbg(xhci, "ep ring empty, Set new dequeue = enqueue");
goto deq_found;
} else {
xhci_warn(xhci, "Can't find new dequeue state, missing td\n");
return -EINVAL;
}
}
hw_dequeue = xhci_get_hw_deq(xhci, dev, ep_index, stream_id);
new_seg = ep_ring->deq_seg;
new_deq = ep_ring->dequeue;
new_cycle = hw_dequeue & 0x1;
/*
* We want to find the pointer, segment and cycle state of the new trb
* (the one after current TD's last_trb). We know the cycle state at
* hw_dequeue, so walk the ring until both hw_dequeue and last_trb are
* found.
*/
do {
if (!cycle_found && xhci_trb_virt_to_dma(new_seg, new_deq)
== (dma_addr_t)(hw_dequeue & ~0xf)) {
cycle_found = true;
if (td_last_trb_found)
break;
}
if (new_deq == td->last_trb)
td_last_trb_found = true;
if (cycle_found && trb_is_link(new_deq) &&
link_trb_toggles_cycle(new_deq))
new_cycle ^= 0x1;
next_trb(xhci, ep_ring, &new_seg, &new_deq);
/* Search wrapped around, bail out */
if (new_deq == ep->ring->dequeue) {
xhci_err(xhci, "Error: Failed finding new dequeue state\n");
return -EINVAL;
}
} while (!cycle_found || !td_last_trb_found);
deq_found:
/* Don't update the ring cycle state for the producer (us). */
addr = xhci_trb_virt_to_dma(new_seg, new_deq);
if (addr == 0) {
xhci_warn(xhci, "Can't find dma of new dequeue ptr\n");
xhci_warn(xhci, "deq seg = %p, deq ptr = %p\n", new_seg, new_deq);
return -EINVAL;
}
if ((ep->ep_state & SET_DEQ_PENDING)) {
xhci_warn(xhci, "Set TR Deq already pending, don't submit for 0x%pad\n",
&addr);
return -EBUSY;
}
/* This function gets called from contexts where it cannot sleep */
cmd = xhci_alloc_command(xhci, false, GFP_ATOMIC);
if (!cmd) {
xhci_warn(xhci, "Can't alloc Set TR Deq cmd 0x%pad\n", &addr);
return -ENOMEM;
}
if (stream_id)
trb_sct = SCT_FOR_TRB(SCT_PRI_TR);
ret = queue_command(xhci, cmd,
lower_32_bits(addr) | trb_sct | new_cycle,
upper_32_bits(addr),
STREAM_ID_FOR_TRB(stream_id), SLOT_ID_FOR_TRB(slot_id) |
EP_ID_FOR_TRB(ep_index) | TRB_TYPE(TRB_SET_DEQ), false);
if (ret < 0) {
xhci_free_command(xhci, cmd);
return ret;
}
ep->queued_deq_seg = new_seg;
ep->queued_deq_ptr = new_deq;
xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
"Set TR Deq ptr 0x%llx, cycle %u\n", addr, new_cycle);
/* Stop the TD queueing code from ringing the doorbell until
* this command completes. The HC won't set the dequeue pointer
* if the ring is running, and ringing the doorbell starts the
* ring running.
*/
ep->ep_state |= SET_DEQ_PENDING;
xhci_ring_cmd_db(xhci);
return 0;
}
/* flip_cycle means flip the cycle bit of all but the first and last TRB.
* (The last TRB actually points to the ring enqueue pointer, which is not part
* of this TD.) This is used to remove partially enqueued isoc TDs from a ring.
@ -890,9 +1024,9 @@ static int xhci_invalidate_cancelled_tds(struct xhci_virt_ep *ep)
struct xhci_td *tmp_td = NULL;
struct xhci_td *cached_td = NULL;
struct xhci_ring *ring;
struct xhci_dequeue_state deq_state;
u64 hw_deq;
unsigned int slot_id = ep->vdev->slot_id;
int err;
xhci = ep->xhci;
@ -935,16 +1069,20 @@ static int xhci_invalidate_cancelled_tds(struct xhci_virt_ep *ep)
}
if (cached_td) {
cached_td->cancel_status = TD_CLEARING_CACHE;
xhci_find_new_dequeue_state(xhci, slot_id, ep->ep_index,
cached_td->urb->stream_id,
cached_td, &deq_state);
xhci_queue_new_dequeue_state(xhci, slot_id, ep->ep_index,
&deq_state);
err = xhci_move_dequeue_past_td(xhci, slot_id, ep->ep_index,
cached_td->urb->stream_id,
cached_td);
/* Failed to move past cached td, try just setting it noop */
if (err) {
td_to_noop(xhci, ring, cached_td, false);
cached_td->cancel_status = TD_CLEARED;
}
cached_td = NULL;
}
return 0;
}
/*
* Returns the TD the endpoint ring halted on.
* Only call for non-running rings without streams.