2 * Intel Wireless WiMAX Connection 2400m
3 * USB specific TX handling
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35 * Intel Corporation <linux-wimax@intel.com>
36 * Yanir Lubetkin <yanirx.lubetkin@intel.com>
37 * - Initial implementation
38 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
39 * - Split transport/device specific
42 * Takes the TX messages in the i2400m's driver TX FIFO and sends them
43 * to the device until there are no more.
45 * If we fail sending the message, we just drop it. There isn't much
46 * we can do at this point. We could also retry, but the USB stack has
47 * already retried and still failed, so there is not much of a
48 * point. As well, most of the traffic is network, which has recovery
49 * methods for dropped packets.
51 * For sending we just obtain a FIFO buffer to send, send it to the
52 * USB bulk out, tell the TX FIFO code we have sent it; query for
53 * another one, etc... until done.
55 * We use a thread so we can call usb_autopm_enable() and
56 * usb_autopm_disable() for each transaction; this way when the device
57 * goes idle, it will suspend. It also has less overhead than a
58 * dedicated workqueue, as it is being used for a single task.
63 * i2400mu_tx_release()
65 * i2400mu_bus_tx_kick() - Called by the tx.c code when there
66 * is new data in the FIFO.
69 * i2400m_tx_msg_sent()
71 #include "i2400m-usb.h"
74 #define D_SUBMODULE tx
75 #include "usb-debug-levels.h"
79 * Get the next TX message in the TX FIFO and send it to the device
81 * Note that any iteration consumes a message to be sent, no matter if
82 * it succeeds or fails (we have no real way to retry or complain).
84 * Return: 0 if ok, < 0 errno code on hard error.
87 int i2400mu_tx(struct i2400mu
*i2400mu
, struct i2400m_msg_hdr
*tx_msg
,
91 struct i2400m
*i2400m
= &i2400mu
->i2400m
;
92 struct device
*dev
= &i2400mu
->usb_iface
->dev
;
93 int usb_pipe
, sent_size
, do_autopm
;
94 struct usb_endpoint_descriptor
*epd
;
96 d_fnstart(4, dev
, "(i2400mu %p)\n", i2400mu
);
97 do_autopm
= atomic_read(&i2400mu
->do_autopm
);
99 usb_autopm_get_interface(i2400mu
->usb_iface
) : 0;
101 dev_err(dev
, "TX: can't get autopm: %d\n", result
);
104 epd
= usb_get_epd(i2400mu
->usb_iface
, i2400mu
->endpoint_cfg
.bulk_out
);
105 usb_pipe
= usb_sndbulkpipe(i2400mu
->usb_dev
, epd
->bEndpointAddress
);
107 result
= usb_bulk_msg(i2400mu
->usb_dev
, usb_pipe
,
108 tx_msg
, tx_msg_size
, &sent_size
, 200);
109 usb_mark_last_busy(i2400mu
->usb_dev
);
112 if (sent_size
!= tx_msg_size
) { /* Too short? drop it */
113 dev_err(dev
, "TX: short write (%d B vs %zu "
114 "expected)\n", sent_size
, tx_msg_size
);
120 * Stall -- maybe the device is choking with our
121 * requests. Clear it and give it some time. If they
122 * happen to often, it might be another symptom, so we
125 * No error handling for usb_clear_halt(0; if it
126 * works, the retry works; if it fails, this switch
127 * does the error handling for us.
129 if (edc_inc(&i2400mu
->urb_edc
,
130 10 * EDC_MAX_ERRORS
, EDC_ERROR_TIMEFRAME
)) {
131 dev_err(dev
, "BM-CMD: too many stalls in "
132 "URB; resetting device\n");
133 usb_queue_reset_device(i2400mu
->usb_iface
);
136 usb_clear_halt(i2400mu
->usb_dev
, usb_pipe
);
137 msleep(10); /* give the device some time */
140 case -EINVAL
: /* while removing driver */
141 case -ENODEV
: /* dev disconnect ... */
142 case -ENOENT
: /* just ignore it */
143 case -ESHUTDOWN
: /* and exit */
147 default: /* Some error? */
148 if (edc_inc(&i2400mu
->urb_edc
,
149 EDC_MAX_ERRORS
, EDC_ERROR_TIMEFRAME
)) {
150 dev_err(dev
, "TX: maximum errors in URB "
151 "exceeded; resetting device\n");
152 usb_queue_reset_device(i2400mu
->usb_iface
);
154 dev_err(dev
, "TX: cannot send URB; retrying. "
155 "tx_msg @%zu %zu B [%d sent]: %d\n",
156 (void *) tx_msg
- i2400m
->tx_buf
,
157 tx_msg_size
, sent_size
, result
);
162 usb_autopm_put_interface(i2400mu
->usb_iface
);
163 d_fnend(4, dev
, "(i2400mu %p) = result\n", i2400mu
);
169 * Get the next TX message in the TX FIFO and send it to the device
171 * Note we exit the loop if i2400mu_tx() fails; that function only
172 * fails on hard error (failing to tx a buffer not being one of them,
178 int i2400mu_txd(void *_i2400mu
)
180 struct i2400mu
*i2400mu
= _i2400mu
;
181 struct i2400m
*i2400m
= &i2400mu
->i2400m
;
182 struct device
*dev
= &i2400mu
->usb_iface
->dev
;
183 struct i2400m_msg_hdr
*tx_msg
;
187 d_fnstart(4, dev
, "(i2400mu %p)\n", i2400mu
);
189 spin_lock_irqsave(&i2400m
->tx_lock
, flags
);
190 BUG_ON(i2400mu
->tx_kthread
!= NULL
);
191 i2400mu
->tx_kthread
= current
;
192 spin_unlock_irqrestore(&i2400m
->tx_lock
, flags
);
195 d_printf(2, dev
, "TX: waiting for messages\n");
197 wait_event_interruptible(
199 (kthread_should_stop() /* check this first! */
200 || (tx_msg
= i2400m_tx_msg_get(i2400m
, &tx_msg_size
)))
202 if (kthread_should_stop())
204 WARN_ON(tx_msg
== NULL
); /* should not happen...*/
205 d_printf(2, dev
, "TX: submitting %zu bytes\n", tx_msg_size
);
206 d_dump(5, dev
, tx_msg
, tx_msg_size
);
207 /* Yeah, we ignore errors ... not much we can do */
208 i2400mu_tx(i2400mu
, tx_msg
, tx_msg_size
);
209 i2400m_tx_msg_sent(i2400m
); /* ack it, advance the FIFO */
212 spin_lock_irqsave(&i2400m
->tx_lock
, flags
);
213 i2400mu
->tx_kthread
= NULL
;
214 spin_unlock_irqrestore(&i2400m
->tx_lock
, flags
);
216 d_fnend(4, dev
, "(i2400mu %p)\n", i2400mu
);
222 * i2400m TX engine notifies us that there is data in the FIFO ready
225 * If there is a URB in flight, don't do anything; when it finishes,
226 * it will see there is data in the FIFO and send it. Else, just
229 void i2400mu_bus_tx_kick(struct i2400m
*i2400m
)
231 struct i2400mu
*i2400mu
= container_of(i2400m
, struct i2400mu
, i2400m
);
232 struct device
*dev
= &i2400mu
->usb_iface
->dev
;
234 d_fnstart(3, dev
, "(i2400m %p) = void\n", i2400m
);
235 wake_up_all(&i2400mu
->tx_wq
);
236 d_fnend(3, dev
, "(i2400m %p) = void\n", i2400m
);
240 int i2400mu_tx_setup(struct i2400mu
*i2400mu
)
243 struct i2400m
*i2400m
= &i2400mu
->i2400m
;
244 struct device
*dev
= &i2400mu
->usb_iface
->dev
;
245 struct wimax_dev
*wimax_dev
= &i2400m
->wimax_dev
;
246 struct task_struct
*kthread
;
248 kthread
= kthread_run(i2400mu_txd
, i2400mu
, "%s-tx",
250 /* the kthread function sets i2400mu->tx_thread */
251 if (IS_ERR(kthread
)) {
252 result
= PTR_ERR(kthread
);
253 dev_err(dev
, "TX: cannot start thread: %d\n", result
);
258 void i2400mu_tx_release(struct i2400mu
*i2400mu
)
261 struct i2400m
*i2400m
= &i2400mu
->i2400m
;
262 struct device
*dev
= i2400m_dev(i2400m
);
263 struct task_struct
*kthread
;
265 spin_lock_irqsave(&i2400m
->tx_lock
, flags
);
266 kthread
= i2400mu
->tx_kthread
;
267 i2400mu
->tx_kthread
= NULL
;
268 spin_unlock_irqrestore(&i2400m
->tx_lock
, flags
);
270 kthread_stop(kthread
);
272 d_printf(1, dev
, "TX: kthread had already exited\n");