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Diffstat (limited to 'drivers/staging/wimax/i2400m/usb-rx.c')
-rw-r--r--drivers/staging/wimax/i2400m/usb-rx.c462
1 files changed, 0 insertions, 462 deletions
diff --git a/drivers/staging/wimax/i2400m/usb-rx.c b/drivers/staging/wimax/i2400m/usb-rx.c
deleted file mode 100644
index 5b64bda7d9e7..000000000000
--- a/drivers/staging/wimax/i2400m/usb-rx.c
+++ /dev/null
@@ -1,462 +0,0 @@
-/*
- * Intel Wireless WiMAX Connection 2400m
- * USB RX handling
- *
- *
- * Copyright (C) 2007-2008 Intel Corporation. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * * Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- * * Neither the name of Intel Corporation nor the names of its
- * contributors may be used to endorse or promote products derived
- * from this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- *
- * Intel Corporation <linux-wimax@intel.com>
- * Yanir Lubetkin <yanirx.lubetkin@intel.com>
- * - Initial implementation
- * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
- * - Use skb_clone(), break up processing in chunks
- * - Split transport/device specific
- * - Make buffer size dynamic to exert less memory pressure
- *
- *
- * This handles the RX path on USB.
- *
- * When a notification is received that says 'there is RX data ready',
- * we call i2400mu_rx_kick(); that wakes up the RX kthread, which
- * reads a buffer from USB and passes it to i2400m_rx() in the generic
- * handling code. The RX buffer has an specific format that is
- * described in rx.c.
- *
- * We use a kernel thread in a loop because:
- *
- * - we want to be able to call the USB power management get/put
- * functions (blocking) before each transaction.
- *
- * - We might get a lot of notifications and we don't want to submit
- * a zillion reads; by serializing, we are throttling.
- *
- * - RX data processing can get heavy enough so that it is not
- * appropriate for doing it in the USB callback; thus we run it in a
- * process context.
- *
- * We provide a read buffer of an arbitrary size (short of a page); if
- * the callback reports -EOVERFLOW, it means it was too small, so we
- * just double the size and retry (being careful to append, as
- * sometimes the device provided some data). Every now and then we
- * check if the average packet size is smaller than the current packet
- * size and if so, we halve it. At the end, the size of the
- * preallocated buffer should be following the average received
- * transaction size, adapting dynamically to it.
- *
- * ROADMAP
- *
- * i2400mu_rx_kick() Called from notif.c when we get a
- * 'data ready' notification
- * i2400mu_rxd() Kernel RX daemon
- * i2400mu_rx() Receive USB data
- * i2400m_rx() Send data to generic i2400m RX handling
- *
- * i2400mu_rx_setup() called from i2400mu_bus_dev_start()
- *
- * i2400mu_rx_release() called from i2400mu_bus_dev_stop()
- */
-#include <linux/workqueue.h>
-#include <linux/slab.h>
-#include <linux/usb.h>
-#include "i2400m-usb.h"
-
-
-#define D_SUBMODULE rx
-#include "usb-debug-levels.h"
-
-/*
- * Dynamic RX size
- *
- * We can't let the rx_size be a multiple of 512 bytes (the RX
- * endpoint's max packet size). On some USB host controllers (we
- * haven't been able to fully characterize which), if the device is
- * about to send (for example) X bytes and we only post a buffer to
- * receive n*512, it will fail to mark that as babble (so that
- * i2400mu_rx() [case -EOVERFLOW] can resize the buffer and get the
- * rest).
- *
- * So on growing or shrinking, if it is a multiple of the
- * maxpacketsize, we remove some (instead of incresing some, so in a
- * buddy allocator we try to waste less space).
- *
- * Note we also need a hook for this on i2400mu_rx() -- when we do the
- * first read, we are sure we won't hit this spot because
- * i240mm->rx_size has been set properly. However, if we have to
- * double because of -EOVERFLOW, when we launch the read to get the
- * rest of the data, we *have* to make sure that also is not a
- * multiple of the max_pkt_size.
- */
-
-static
-size_t i2400mu_rx_size_grow(struct i2400mu *i2400mu)
-{
- struct device *dev = &i2400mu->usb_iface->dev;
- size_t rx_size;
- const size_t max_pkt_size = 512;
-
- rx_size = 2 * i2400mu->rx_size;
- if (rx_size % max_pkt_size == 0) {
- rx_size -= 8;
- d_printf(1, dev,
- "RX: expected size grew to %zu [adjusted -8] "
- "from %zu\n",
- rx_size, i2400mu->rx_size);
- } else
- d_printf(1, dev,
- "RX: expected size grew to %zu from %zu\n",
- rx_size, i2400mu->rx_size);
- return rx_size;
-}
-
-
-static
-void i2400mu_rx_size_maybe_shrink(struct i2400mu *i2400mu)
-{
- const size_t max_pkt_size = 512;
- struct device *dev = &i2400mu->usb_iface->dev;
-
- if (unlikely(i2400mu->rx_size_cnt >= 100
- && i2400mu->rx_size_auto_shrink)) {
- size_t avg_rx_size =
- i2400mu->rx_size_acc / i2400mu->rx_size_cnt;
- size_t new_rx_size = i2400mu->rx_size / 2;
- if (avg_rx_size < new_rx_size) {
- if (new_rx_size % max_pkt_size == 0) {
- new_rx_size -= 8;
- d_printf(1, dev,
- "RX: expected size shrank to %zu "
- "[adjusted -8] from %zu\n",
- new_rx_size, i2400mu->rx_size);
- } else
- d_printf(1, dev,
- "RX: expected size shrank to %zu "
- "from %zu\n",
- new_rx_size, i2400mu->rx_size);
- i2400mu->rx_size = new_rx_size;
- i2400mu->rx_size_cnt = 0;
- i2400mu->rx_size_acc = i2400mu->rx_size;
- }
- }
-}
-
-/*
- * Receive a message with payloads from the USB bus into an skb
- *
- * @i2400mu: USB device descriptor
- * @rx_skb: skb where to place the received message
- *
- * Deals with all the USB-specifics of receiving, dynamically
- * increasing the buffer size if so needed. Returns the payload in the
- * skb, ready to process. On a zero-length packet, we retry.
- *
- * On soft USB errors, we retry (until they become too frequent and
- * then are promoted to hard); on hard USB errors, we reset the
- * device. On other errors (skb realloacation, we just drop it and
- * hope for the next invocation to solve it).
- *
- * Returns: pointer to the skb if ok, ERR_PTR on error.
- * NOTE: this function might realloc the skb (if it is too small),
- * so always update with the one returned.
- * ERR_PTR() is < 0 on error.
- * Will return NULL if it cannot reallocate -- this can be
- * considered a transient retryable error.
- */
-static
-struct sk_buff *i2400mu_rx(struct i2400mu *i2400mu, struct sk_buff *rx_skb)
-{
- int result = 0;
- struct device *dev = &i2400mu->usb_iface->dev;
- int usb_pipe, read_size, rx_size, do_autopm;
- struct usb_endpoint_descriptor *epd;
- const size_t max_pkt_size = 512;
-
- d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);
- do_autopm = atomic_read(&i2400mu->do_autopm);
- result = do_autopm ?
- usb_autopm_get_interface(i2400mu->usb_iface) : 0;
- if (result < 0) {
- dev_err(dev, "RX: can't get autopm: %d\n", result);
- do_autopm = 0;
- }
- epd = usb_get_epd(i2400mu->usb_iface, i2400mu->endpoint_cfg.bulk_in);
- usb_pipe = usb_rcvbulkpipe(i2400mu->usb_dev, epd->bEndpointAddress);
-retry:
- rx_size = skb_end_pointer(rx_skb) - rx_skb->data - rx_skb->len;
- if (unlikely(rx_size % max_pkt_size == 0)) {
- rx_size -= 8;
- d_printf(1, dev, "RX: rx_size adapted to %d [-8]\n", rx_size);
- }
- result = usb_bulk_msg(
- i2400mu->usb_dev, usb_pipe, rx_skb->data + rx_skb->len,
- rx_size, &read_size, 200);
- usb_mark_last_busy(i2400mu->usb_dev);
- switch (result) {
- case 0:
- if (read_size == 0)
- goto retry; /* ZLP, just resubmit */
- skb_put(rx_skb, read_size);
- break;
- case -EPIPE:
- /*
- * Stall -- maybe the device is choking with our
- * requests. Clear it and give it some time. If they
- * happen to often, it might be another symptom, so we
- * reset.
- *
- * No error handling for usb_clear_halt(0; if it
- * works, the retry works; if it fails, this switch
- * does the error handling for us.
- */
- if (edc_inc(&i2400mu->urb_edc,
- 10 * EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
- dev_err(dev, "BM-CMD: too many stalls in "
- "URB; resetting device\n");
- goto do_reset;
- }
- usb_clear_halt(i2400mu->usb_dev, usb_pipe);
- msleep(10); /* give the device some time */
- goto retry;
- case -EINVAL: /* while removing driver */
- case -ENODEV: /* dev disconnect ... */
- case -ENOENT: /* just ignore it */
- case -ESHUTDOWN:
- case -ECONNRESET:
- break;
- case -EOVERFLOW: { /* too small, reallocate */
- struct sk_buff *new_skb;
- rx_size = i2400mu_rx_size_grow(i2400mu);
- if (rx_size <= (1 << 16)) /* cap it */
- i2400mu->rx_size = rx_size;
- else if (printk_ratelimit()) {
- dev_err(dev, "BUG? rx_size up to %d\n", rx_size);
- result = -EINVAL;
- goto out;
- }
- skb_put(rx_skb, read_size);
- new_skb = skb_copy_expand(rx_skb, 0, rx_size - rx_skb->len,
- GFP_KERNEL);
- if (new_skb == NULL) {
- kfree_skb(rx_skb);
- rx_skb = NULL;
- goto out; /* drop it...*/
- }
- kfree_skb(rx_skb);
- rx_skb = new_skb;
- i2400mu->rx_size_cnt = 0;
- i2400mu->rx_size_acc = i2400mu->rx_size;
- d_printf(1, dev, "RX: size changed to %d, received %d, "
- "copied %d, capacity %ld\n",
- rx_size, read_size, rx_skb->len,
- (long) skb_end_offset(new_skb));
- goto retry;
- }
- /* In most cases, it happens due to the hardware scheduling a
- * read when there was no data - unfortunately, we have no way
- * to tell this timeout from a USB timeout. So we just ignore
- * it. */
- case -ETIMEDOUT:
- dev_err(dev, "RX: timeout: %d\n", result);
- result = 0;
- break;
- default: /* Any error */
- if (edc_inc(&i2400mu->urb_edc,
- EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME))
- goto error_reset;
- dev_err(dev, "RX: error receiving URB: %d, retrying\n", result);
- goto retry;
- }
-out:
- if (do_autopm)
- usb_autopm_put_interface(i2400mu->usb_iface);
- d_fnend(4, dev, "(i2400mu %p) = %p\n", i2400mu, rx_skb);
- return rx_skb;
-
-error_reset:
- dev_err(dev, "RX: maximum errors in URB exceeded; "
- "resetting device\n");
-do_reset:
- usb_queue_reset_device(i2400mu->usb_iface);
- rx_skb = ERR_PTR(result);
- goto out;
-}
-
-
-/*
- * Kernel thread for USB reception of data
- *
- * This thread waits for a kick; once kicked, it will allocate an skb
- * and receive a single message to it from USB (using
- * i2400mu_rx()). Once received, it is passed to the generic i2400m RX
- * code for processing.
- *
- * When done processing, it runs some dirty statistics to verify if
- * the last 100 messages received were smaller than half of the
- * current RX buffer size. In that case, the RX buffer size is
- * halved. This will helps lowering the pressure on the memory
- * allocator.
- *
- * Hard errors force the thread to exit.
- */
-static
-int i2400mu_rxd(void *_i2400mu)
-{
- int result = 0;
- struct i2400mu *i2400mu = _i2400mu;
- struct i2400m *i2400m = &i2400mu->i2400m;
- struct device *dev = &i2400mu->usb_iface->dev;
- struct net_device *net_dev = i2400m->wimax_dev.net_dev;
- size_t pending;
- int rx_size;
- struct sk_buff *rx_skb;
- unsigned long flags;
-
- d_fnstart(4, dev, "(i2400mu %p)\n", i2400mu);
- spin_lock_irqsave(&i2400m->rx_lock, flags);
- BUG_ON(i2400mu->rx_kthread != NULL);
- i2400mu->rx_kthread = current;
- spin_unlock_irqrestore(&i2400m->rx_lock, flags);
- while (1) {
- d_printf(2, dev, "RX: waiting for messages\n");
- pending = 0;
- wait_event_interruptible(
- i2400mu->rx_wq,
- (kthread_should_stop() /* check this first! */
- || (pending = atomic_read(&i2400mu->rx_pending_count)))
- );
- if (kthread_should_stop())
- break;
- if (pending == 0)
- continue;
- rx_size = i2400mu->rx_size;
- d_printf(2, dev, "RX: reading up to %d bytes\n", rx_size);
- rx_skb = __netdev_alloc_skb(net_dev, rx_size, GFP_KERNEL);
- if (rx_skb == NULL) {
- dev_err(dev, "RX: can't allocate skb [%d bytes]\n",
- rx_size);
- msleep(50); /* give it some time? */
- continue;
- }
-
- /* Receive the message with the payloads */
- rx_skb = i2400mu_rx(i2400mu, rx_skb);
- result = PTR_ERR(rx_skb);
- if (IS_ERR(rx_skb))
- goto out;
- atomic_dec(&i2400mu->rx_pending_count);
- if (rx_skb == NULL || rx_skb->len == 0) {
- /* some "ignorable" condition */
- kfree_skb(rx_skb);
- continue;
- }
-
- /* Deliver the message to the generic i2400m code */
- i2400mu->rx_size_cnt++;
- i2400mu->rx_size_acc += rx_skb->len;
- result = i2400m_rx(i2400m, rx_skb);
- if (result == -EIO
- && edc_inc(&i2400mu->urb_edc,
- EDC_MAX_ERRORS, EDC_ERROR_TIMEFRAME)) {
- goto error_reset;
- }
-
- /* Maybe adjust RX buffer size */
- i2400mu_rx_size_maybe_shrink(i2400mu);
- }
- result = 0;
-out:
- spin_lock_irqsave(&i2400m->rx_lock, flags);
- i2400mu->rx_kthread = NULL;
- spin_unlock_irqrestore(&i2400m->rx_lock, flags);
- d_fnend(4, dev, "(i2400mu %p) = %d\n", i2400mu, result);
- return result;
-
-error_reset:
- dev_err(dev, "RX: maximum errors in received buffer exceeded; "
- "resetting device\n");
- usb_queue_reset_device(i2400mu->usb_iface);
- goto out;
-}
-
-
-/*
- * Start reading from the device
- *
- * @i2400m: device instance
- *
- * Notify the RX thread that there is data pending.
- */
-void i2400mu_rx_kick(struct i2400mu *i2400mu)
-{
- struct i2400m *i2400m = &i2400mu->i2400m;
- struct device *dev = &i2400mu->usb_iface->dev;
-
- d_fnstart(3, dev, "(i2400mu %p)\n", i2400m);
- atomic_inc(&i2400mu->rx_pending_count);
- wake_up_all(&i2400mu->rx_wq);
- d_fnend(3, dev, "(i2400m %p) = void\n", i2400m);
-}
-
-
-int i2400mu_rx_setup(struct i2400mu *i2400mu)
-{
- int result = 0;
- struct i2400m *i2400m = &i2400mu->i2400m;
- struct device *dev = &i2400mu->usb_iface->dev;
- struct wimax_dev *wimax_dev = &i2400m->wimax_dev;
- struct task_struct *kthread;
-
- kthread = kthread_run(i2400mu_rxd, i2400mu, "%s-rx",
- wimax_dev->name);
- /* the kthread function sets i2400mu->rx_thread */
- if (IS_ERR(kthread)) {
- result = PTR_ERR(kthread);
- dev_err(dev, "RX: cannot start thread: %d\n", result);
- }
- return result;
-}
-
-
-void i2400mu_rx_release(struct i2400mu *i2400mu)
-{
- unsigned long flags;
- struct i2400m *i2400m = &i2400mu->i2400m;
- struct device *dev = i2400m_dev(i2400m);
- struct task_struct *kthread;
-
- spin_lock_irqsave(&i2400m->rx_lock, flags);
- kthread = i2400mu->rx_kthread;
- i2400mu->rx_kthread = NULL;
- spin_unlock_irqrestore(&i2400m->rx_lock, flags);
- if (kthread)
- kthread_stop(kthread);
- else
- d_printf(1, dev, "RX: kthread had already exited\n");
-}
-
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