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* Intel Wireless WiMAX Connection 2400m
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* USB specific TX handling
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* Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* * Neither the name of Intel Corporation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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* Intel Corporation <linux-wimax@intel.com>
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* Yanir Lubetkin <yanirx.lubetkin@intel.com>
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* - Initial implementation
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* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
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* - Split transport/device specific
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* Takes the TX messages in the i2400m's driver TX FIFO and sends them
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* to the device until there are no more.
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* If we fail sending the message, we just drop it. There isn't much
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* we can do at this point. We could also retry, but the USB stack has
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* already retried and still failed, so there is not much of a
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* point. As well, most of the traffic is network, which has recovery
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* methods for dropped packets.
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* For sending we just obtain a FIFO buffer to send, send it to the
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* USB bulk out, tell the TX FIFO code we have sent it; query for
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* another one, etc... until done.
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* We use a thread so we can call usb_autopm_enable() and
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* usb_autopm_disable() for each transaction; this way when the device
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* goes idle, it will suspend. It also has less overhead than a
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* dedicated workqueue, as it is being used for a single task.
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* i2400mu_tx_release()
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* i2400mu_bus_tx_kick() - Called by the tx.c code when there
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* is new data in the FIFO.
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* i2400m_tx_msg_sent()
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#include "i2400m-usb.h"
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#define D_SUBMODULE tx
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#include "usb-debug-levels.h"
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* Get the next TX message in the TX FIFO and send it to the device
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* Note that any iteration consumes a message to be sent, no matter if
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* it succeeds or fails (we have no real way to retry or complain).
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* Return: 0 if ok, < 0 errno code on hard error.
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int i2400mu_tx(struct i2400mu *i2400mu, struct i2400m_msg_hdr *tx_msg,
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struct i2400m *i2400m = &i2400mu->i2400m;
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struct device *dev = &i2400mu->usb_iface->dev;
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int usb_pipe, sent_size, do_autopm;
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struct usb_endpoint_descriptor *epd;
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d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);
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do_autopm = atomic_read(&i2400mu->do_autopm);
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usb_autopm_get_interface(i2400mu->usb_iface) : 0;
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dev_err(dev, "TX: can't get autopm: %d\n", result);
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epd = usb_get_epd(i2400mu->usb_iface, i2400mu->endpoint_cfg.bulk_out);
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usb_pipe = usb_sndbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
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result = usb_bulk_msg(i2400mu->usb_dev, usb_pipe,
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tx_msg, tx_msg_size, &sent_size, 200);
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usb_mark_last_busy(i2400mu->usb_dev);
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if (sent_size != tx_msg_size) { /* Too short? drop it */
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dev_err(dev, "TX: short write (%d B vs %zu "
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"expected)\n", sent_size, tx_msg_size);
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* Stall -- maybe the device is choking with our
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* requests. Clear it and give it some time. If they
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* happen to often, it might be another symptom, so we
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* No error handling for usb_clear_halt(0; if it
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* works, the retry works; if it fails, this switch
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* does the error handling for us.
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if (edc_inc(&i2400mu->urb_edc,
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10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
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dev_err(dev, "BM-CMD: too many stalls in "
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"URB; resetting device\n");
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usb_queue_reset_device(i2400mu->usb_iface);
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usb_clear_halt(i2400mu->usb_dev, usb_pipe);
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msleep(10); /* give the device some time */
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case -EINVAL: /* while removing driver */
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case -ENODEV: /* dev disconnect ... */
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case -ENOENT: /* just ignore it */
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case -ESHUTDOWN: /* and exit */
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default: /* Some error? */
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if (edc_inc(&i2400mu->urb_edc,
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EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
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dev_err(dev, "TX: maximum errors in URB "
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"exceeded; resetting device\n");
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usb_queue_reset_device(i2400mu->usb_iface);
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dev_err(dev, "TX: cannot send URB; retrying. "
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"tx_msg @%zu %zu B [%d sent]: %d\n",
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(void *) tx_msg - i2400m->tx_buf,
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tx_msg_size, sent_size, result);
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usb_autopm_put_interface(i2400mu->usb_iface);
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d_fnend(4, dev, "(i2400mu %p) = result\n", i2400mu);
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* Get the next TX message in the TX FIFO and send it to the device
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* Note we exit the loop if i2400mu_tx() fails; that function only
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* fails on hard error (failing to tx a buffer not being one of them,
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int i2400mu_txd(void *_i2400mu)
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struct i2400mu *i2400mu = _i2400mu;
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struct i2400m *i2400m = &i2400mu->i2400m;
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struct device *dev = &i2400mu->usb_iface->dev;
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struct i2400m_msg_hdr *tx_msg;
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d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);
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spin_lock_irqsave(&i2400m->tx_lock, flags);
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BUG_ON(i2400mu->tx_kthread != NULL);
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i2400mu->tx_kthread = current;
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spin_unlock_irqrestore(&i2400m->tx_lock, flags);
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d_printf(2, dev, "TX: waiting for messages\n");
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wait_event_interruptible(
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(kthread_should_stop() /* check this first! */
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|| (tx_msg = i2400m_tx_msg_get(i2400m, &tx_msg_size)))
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if (kthread_should_stop())
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WARN_ON(tx_msg == NULL); /* should not happen...*/
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d_printf(2, dev, "TX: submitting %zu bytes\n", tx_msg_size);
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d_dump(5, dev, tx_msg, tx_msg_size);
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/* Yeah, we ignore errors ... not much we can do */
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i2400mu_tx(i2400mu, tx_msg, tx_msg_size);
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i2400m_tx_msg_sent(i2400m); /* ack it, advance the FIFO */
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spin_lock_irqsave(&i2400m->tx_lock, flags);
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i2400mu->tx_kthread = NULL;
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spin_unlock_irqrestore(&i2400m->tx_lock, flags);
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d_fnend(4, dev, "(i2400mu %p) = %d\n", i2400mu, result);
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* i2400m TX engine notifies us that there is data in the FIFO ready
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* If there is a URB in flight, don't do anything; when it finishes,
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* it will see there is data in the FIFO and send it. Else, just
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void i2400mu_bus_tx_kick(struct i2400m *i2400m)
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struct i2400mu *i2400mu = container_of(i2400m, struct i2400mu, i2400m);
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struct device *dev = &i2400mu->usb_iface->dev;
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d_fnstart(3, dev, "(i2400m %p) = void\n", i2400m);
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wake_up_all(&i2400mu->tx_wq);
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d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
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int i2400mu_tx_setup(struct i2400mu *i2400mu)
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struct i2400m *i2400m = &i2400mu->i2400m;
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struct device *dev = &i2400mu->usb_iface->dev;
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struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
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struct task_struct *kthread;
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kthread = kthread_run(i2400mu_txd, i2400mu, "%s-tx",
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/* the kthread function sets i2400mu->tx_thread */
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if (IS_ERR(kthread)) {
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result = PTR_ERR(kthread);
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dev_err(dev, "TX: cannot start thread: %d\n", result);
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void i2400mu_tx_release(struct i2400mu *i2400mu)
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struct i2400m *i2400m = &i2400mu->i2400m;
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struct device *dev = i2400m_dev(i2400m);
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struct task_struct *kthread;
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spin_lock_irqsave(&i2400m->tx_lock, flags);
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kthread = i2400mu->tx_kthread;
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i2400mu->tx_kthread = NULL;
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spin_unlock_irqrestore(&i2400m->tx_lock, flags);
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kthread_stop(kthread);
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d_printf(1, dev, "TX: kthread had already exited\n");