In case we have many started requests and one of them in the middle is
completed with Missed Isoc, let's not End Transfer as that would
result in us loosing (possibly) many more intervals.

Instead, let's allow the controller to go through its list of started
requests.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Avoid a prototype when the function can be defined earlier. No
functional changes, cleanup only.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Instead of having a prototype for a function that's defined a few
lines down, let's just move definition to the place where prototype
was.

No functional changes, cleanup only.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

In a few places, the argument is completely unnecessary. On places
where it's needed, we can get it from dep->dwc.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Those two arguments refer to a single bitfield in the register. In
order to simplify the code, we can combine them into a single argument
and expect caller to pass the correct action argument at all times.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This just makes it slightly easier to read. No functional changes.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

No functional changes, it just makes the code slightly easier to read.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Code is just as readable without it.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We can declare it inside list_for_each_entry_safe() loop and reduce
its scope.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Misc cleanup. No functional changes.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We will only have event status of IOC when IOC bit is set in
TRB. There's no need to check both bits.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We know that only OUT endpoints can trigger SHORT. We also know that
count MUST be > 0 whenever SHORT triggers.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We can just call reclaim_trb_linear instead of reimplementing it.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Minor cleanup, no functional changes.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We are trying to kick transfers on Isochronous endpoints in a more
controlled manner now. And this ended up rendering this piece of code
unnecessary.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

instead of having one big loop, let's split it down into two smaller
handlers: one for linear buffers and one for scatterlist.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Just a minor simplification, no functional changes.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

After all the previous changes, it's now a lot clearer how isoc
transfers should be managed. We don't need to try to End Transfers
from ep_queue since that's already done by cleanup_requests.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Now, this part of the code is duplicated and brings no extra value to
the driver. Let's remove it.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

In case we get an event with status set to Missed Isoc, this means we
have missed an isochronous interval and should issue End Transfer
command and wait for the following XferNotReady.

Let's do that early, rather than late.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

It's only written to, never read. We can remove it now.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We don't need to return a value anymore here. Let's remove it.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

It has no use anymore.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

By now, it has the same semantics as DWC3_EP_TRANSFER_STARTED, but
that has a much more descriptive name.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We will need an up-to-date frame_number from XferInProgress too when
future patches improve our handling of Isoc endpoints.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

The core requires the extra two bits of information for properly
scheduling Isochronous transfers. This means that we can't rely on
__dwc3_gadget_get_frame(). Let's always cache uFrame number from
XferNotReady instead.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Endpoint handlers need to know about endpoints, not dwc. If they
really need access to dwc (e.g. for printing error messages) we have a
reference to it tucked inside the endpoint.

This patch has no functional changes, it's simply moving things around.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Cleanup only, no functional changes. Just making code easier to
follow.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Cleanup only, no functional changes. This just matches the event name
with its handler.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We *KNOW* which events we enable for which endpoint types and
we *KNOW* when they'll trigger. The endpoint type checks are
pointless.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

That has never proven useful in any way. Just remove it.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This patch simply renames two functions to more descriptive names so
that it's easier to understand what they're doing.

Cleanup only, no functional changes.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Instead of constantly calling kick transfer everything some event
shows up, let's just rely on the fact that we send Update Transfer
every time a new request is queued.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Now that we're making sure we don't have XferComplete events, we can
rename this function to what it actually handles:
dwc3_gadget_endpoint_transfer_in_progress()
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

XferComplete is enabled only for the default control pipe, let's make
that clear in the code.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

We don't use XferNotReady for anything other than Default Control
Pipe, which is handled in ep0.c, and Isochronous endpoints. Let's make
that clear in the code.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Interrupt endpoints behave much like Bulk endpoints with the exception
that they are periodic. We can pre-issue Start Transfer exactly as we
do for Bulk endpoints.

While at that, remove one trailing blank line which is unnecessary.
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

The present code correctly fetches the req which were previously not
queued from the started_list but fails to continue queuing from the sg
where it previously stopped queuing (because of the unavailable TRB's).
This patch correct's the code to continue queuing from the correct sg
present in the sglist.

For example, consider 5 sgs in req. Because of limited TRB's among the
5 sgs only 3 got queued. This patch corrects the code to start queuing
from correct sg i.e 4th sg when the TRBs are available.
Signed-off-by: NAnurag Kumar Vulisha <anuragku@xilinx.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

The code logic in dwc3_prepare_one_trb() incorrectly uses the address
and length fields present in req packet for mapping TRB's instead of
using the address and length fields of scattergather lists. This patch
correct's the code to use sg->address and sg->length when scattergather
lists are present.
Signed-off-by: NAnurag Kumar Vulisha <anuragku@xilinx.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This is a requirement which has always existed but, somehow, wasn't
reflected in the documentation and problems weren't found until now
when Tuba Yavuz found a possible deadlock happening between dwc3 and
f_hid. She described the situation as follows:

spin_lock_irqsave(&hidg->write_spinlock, flags); // first acquire
/* we our function has been disabled by host */
if (!hidg->req) {
	free_ep_req(hidg->in_ep, hidg->req);
	goto try_again;
}

[...]

status = usb_ep_queue(hidg->in_ep, hidg->req, GFP_ATOMIC);
=>
	[...]
	=> usb_gadget_giveback_request
		=>
		f_hidg_req_complete
			=>
			spin_lock_irqsave(&hidg->write_spinlock, flags); // second acquire

Note that this happens because dwc3 would call ->complete() on a
failed usb_ep_queue() due to failed Start Transfer command. This is,
anyway, a theoretical situation because dwc3 currently uses "No
Response Update Transfer" command for Bulk and Interrupt endpoints.

It's still good to make this case impossible to happen even if the "No
Reponse Update Transfer" command is changed.
Reported-by: NTuba Yavuz <tuba@ece.ufl.edu>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>