[PATCH 14/14] USB speedtouch: receive code rewrite

From: Duncan Sands (baldrick@wanadoo.fr)
Date: Tue May 20 2003 - 18:06:58 EST


Main points:
- receive buffers are decoupled from urbs, so an urb can be
resubmitted with a new buffer before the old buffer is processed.
- the packet reconstruction code is much simpler.
- locking is simplified by the fact that only the tasklet launches
receive urbs

 speedtch.c | 459 ++++++++++++++++++++++++-------------------------------------
 1 files changed, 188 insertions(+), 271 deletions(-)

diff -Nru a/drivers/usb/misc/speedtch.c b/drivers/usb/misc/speedtch.c
--- a/drivers/usb/misc/speedtch.c Wed May 21 00:41:16 2003
+++ b/drivers/usb/misc/speedtch.c Wed May 21 00:41:16 2003
@@ -104,8 +104,9 @@
 
 #define UDSL_NUM_RCV_URBS 1
 #define UDSL_NUM_SND_URBS 1
+#define UDSL_NUM_RCV_BUFS (2*UDSL_NUM_RCV_URBS)
 #define UDSL_NUM_SND_BUFS (2*UDSL_NUM_SND_URBS)
-#define UDSL_RCV_BUF_SIZE 64 /* ATM cells */
+#define UDSL_RCV_BUF_SIZE 32 /* ATM cells */
 #define UDSL_SND_BUF_SIZE 64 /* ATM cells */
 
 #define UDSL_IOCTL_LINE_UP 1
@@ -128,9 +129,15 @@
 
 /* receive */
 
+struct udsl_receive_buffer {
+ struct list_head list;
+ unsigned char *base;
+ unsigned int filled_cells;
+};
+
 struct udsl_receiver {
         struct list_head list;
- struct sk_buff *skb;
+ struct udsl_receive_buffer *buffer;
         struct urb *urb;
         struct udsl_instance_data *instance;
 };
@@ -190,14 +197,14 @@
 
         /* receive */
         struct udsl_receiver receivers [UDSL_NUM_RCV_URBS];
+ struct udsl_receive_buffer receive_buffers [UDSL_NUM_RCV_BUFS];
 
- spinlock_t spare_receivers_lock;
+ spinlock_t receive_lock;
         struct list_head spare_receivers;
-
- spinlock_t completed_receivers_lock;
- struct list_head completed_receivers;
+ struct list_head filled_receive_buffers;
 
         struct tasklet_struct receive_tasklet;
+ struct list_head spare_receive_buffers;
 
         /* send */
         struct udsl_sender senders [UDSL_NUM_SND_URBS];
@@ -262,133 +269,110 @@
         return NULL;
 }
 
-static struct sk_buff *udsl_decode_rawcell (struct udsl_instance_data *instance, struct sk_buff *skb, struct udsl_vcc_data **ctx)
+static void udsl_extract_cells (struct udsl_instance_data *instance, unsigned char *source, unsigned int howmany)
 {
- if (!instance || !skb || !ctx)
- return NULL;
- if (!skb->data || !skb->tail)
- return NULL;
-
- while (skb->len) {
- unsigned char *cell = skb->data;
- unsigned char *cell_payload;
- struct udsl_vcc_data *vcc;
- short vpi;
- int vci;
-
- vpi = ((cell [0] & 0x0f) << 4) | (cell [1] >> 4);
- vci = ((cell [1] & 0x0f) << 12) | (cell [2] << 4) | (cell [3] >> 4);
-
- vdbg ("udsl_decode_rawcell (0x%p, 0x%p, 0x%p) called", instance, skb, ctx);
- vdbg ("udsl_decode_rawcell skb->data %p, skb->tail %p", skb->data, skb->tail);
-
- /* here should the header CRC check be... */
-
- if (!(vcc = udsl_find_vcc (instance, vpi, vci))) {
- dbg ("udsl_decode_rawcell: no vcc found for packet on vpi %d, vci %d", vpi, vci);
- __skb_pull (skb, min (skb->len, (unsigned) 53));
+ struct udsl_vcc_data *cached_vcc = NULL;
+ struct atm_vcc *vcc;
+ struct sk_buff *skb;
+ struct udsl_vcc_data *vcc_data;
+ int cached_vci = 0;
+ unsigned int i;
+ unsigned int length;
+ unsigned int pdu_length;
+ int pti;
+ int vci;
+ short cached_vpi = 0;
+ short vpi;
+
+ for (i = 0; i < howmany; i++, source += ATM_CELL_SIZE) {
+ vpi = ((source [0] & 0x0f) << 4) | (source [1] >> 4);
+ vci = ((source [1] & 0x0f) << 12) | (source [2] << 4) | (source [3] >> 4);
+ pti = (source [3] & 0x2) != 0;
+
+ vdbg ("udsl_extract_cells: vpi %hd, vci %d, pti %d", vpi, vci, pti);
+
+ if (cached_vcc && (vci == cached_vci) && (vpi == cached_vpi))
+ vcc_data = cached_vcc;
+ else if ((vcc_data = udsl_find_vcc (instance, vpi, vci))) {
+ cached_vcc = vcc_data;
+ cached_vpi = vpi;
+ cached_vci = vci;
                 } else {
- vdbg ("udsl_decode_rawcell found vcc %p for packet on vpi %d, vci %d", vcc, vpi, vci);
+ dbg ("udsl_extract_cells: unknown vpi/vci (%hd/%d)!", vpi, vci);
+ continue;
+ }
 
- if (skb->len >= 53) {
- cell_payload = cell + 5;
+ vcc = vcc_data->vcc;
 
- if (!vcc->skb)
- vcc->skb = dev_alloc_skb (vcc->max_pdu);
+ if (!vcc_data->skb && !(vcc_data->skb = dev_alloc_skb (vcc_data->max_pdu))) {
+ dbg ("udsl_extract_cells: no memory for skb (vcc: 0x%p)!", vcc);
+ if (pti)
+ atomic_inc (&vcc->stats->rx_err);
+ continue;
+ }
 
- /* if alloc fails, we just drop the cell. it is possible that we can still
- * receive cells on other vcc's
- */
- if (vcc->skb) {
- /* if (buffer overrun) discard received cells until now */
- if ((vcc->skb->len) > (vcc->max_pdu - 48))
- skb_trim (vcc->skb, 0);
-
- /* copy data */
- memcpy (vcc->skb->tail, cell_payload, 48);
- skb_put (vcc->skb, 48);
-
- /* check for end of buffer */
- if (cell [3] & 0x2) {
- struct sk_buff *tmp;
-
- /* the aal5 buffer ends here, cut the buffer. */
- /* buffer will always have at least one whole cell, so */
- /* don't need to check return from skb_pull */
- skb_pull (skb, 53);
- *ctx = vcc;
- tmp = vcc->skb;
- vcc->skb = NULL;
-
- vdbg ("udsl_decode_rawcell returns ATM_AAL5 pdu 0x%p with length %d", tmp, tmp->len);
- return tmp;
- }
- }
- /* flush the cell */
- /* buffer will always contain at least one whole cell, so don't */
- /* need to check return value from skb_pull */
- skb_pull (skb, 53);
- } else {
- /* If data is corrupt and skb doesn't hold a whole cell, flush the lot */
- __skb_pull (skb, skb->len);
- return NULL;
- }
+ skb = vcc_data->skb;
+
+ if (skb->len + ATM_CELL_PAYLOAD > vcc_data->max_pdu) {
+ dbg ("udsl_extract_cells: buffer overrun (max_pdu: %u, skb->len %u, vcc: 0x%p)", vcc_data->max_pdu, skb->len, vcc);
+ /* discard cells already received */
+ skb_trim (skb, 0);
+ BUG_ON (vcc_data->max_pdu < ATM_CELL_PAYLOAD);
                 }
- }
 
- return NULL;
-}
+ memcpy (skb->tail, source + ATM_CELL_HEADER, ATM_CELL_PAYLOAD);
+ __skb_put (skb, ATM_CELL_PAYLOAD);
 
-static struct sk_buff *udsl_decode_aal5 (struct udsl_vcc_data *ctx, struct sk_buff *skb)
-{
- uint crc = 0xffffffff;
- uint length, pdu_crc, pdu_length;
+ if (pti) {
+ length = (source [ATM_CELL_SIZE - 6] << 8) + source [ATM_CELL_SIZE - 5];
 
- vdbg ("udsl_decode_aal5 (0x%p, 0x%p) called", ctx, skb);
+ /* guard against overflow */
+ if (length > ATM_MAX_AAL5_PDU) {
+ dbg ("udsl_extract_cells: bogus length %u (vcc: 0x%p)", length, vcc);
+ goto drop;
+ }
 
- if (skb->len && (skb->len % 48))
- return NULL;
+ pdu_length = UDSL_NUM_CELLS (length) * ATM_CELL_PAYLOAD;
 
- length = (skb->tail [-6] << 8) + skb->tail [-5];
- pdu_crc =
- (skb->tail [-4] << 24) + (skb->tail [-3] << 16) + (skb->tail [-2] << 8) + skb->tail [-1];
- pdu_length = ((length + 47 + 8) / 48) * 48;
+ if (skb->len < pdu_length) {
+ dbg ("udsl_extract_cells: bogus pdu_length %u (skb->len: %u, vcc: 0x%p)", pdu_length, skb->len, vcc);
+ goto drop;
+ }
 
- vdbg ("udsl_decode_aal5: skb->len = %d, length = %d, pdu_crc = 0x%x, pdu_length = %d", skb->len, length, pdu_crc, pdu_length);
+ if (crc32_be (~0, skb->tail - pdu_length, pdu_length) != 0xc704dd7b) {
+ dbg ("udsl_extract_cells: packet failed crc check (vcc: 0x%p)", vcc);
+ goto drop;
+ }
 
- /* is skb long enough ? */
- if (skb->len < pdu_length) {
- atomic_inc (&ctx->vcc->stats->rx_err);
- return NULL;
- }
+ if (!atm_charge (vcc, skb->truesize)) {
+ dbg ("udsl_extract_cells: failed atm_charge (skb->truesize: %u)", skb->truesize);
+ goto drop_no_stats; /* atm_charge increments rx_drop */
+ }
 
- /* is skb too long ? */
- if (skb->len > pdu_length) {
- dbg ("udsl_decode_aal5: Warning: readjusting illegal size %d -> %d", skb->len, pdu_length);
- /* buffer is too long. we can try to recover
- * if we discard the first part of the skb.
- * the crc will decide whether this was ok
- */
- skb_pull (skb, skb->len - pdu_length);
- }
+ /* now that we are sure to send the skb, it is ok to change skb->data */
+ if (skb->len > pdu_length)
+ skb_pull (skb, skb->len - pdu_length); /* discard initial junk */
 
- crc = ~crc32_be (crc, skb->data, pdu_length - 4);
+ skb_trim (skb, length); /* drop zero padding and trailer */
 
- /* check crc */
- if (pdu_crc != crc) {
- dbg ("udsl_decode_aal5: crc check failed!");
- atomic_inc (&ctx->vcc->stats->rx_err);
- return NULL;
- }
+ atomic_inc (&vcc->stats->rx);
 
- /* pdu is ok */
- skb_trim (skb, length);
+ PACKETDEBUG (skb->data, skb->len);
+
+ vdbg ("udsl_extract_cells: sending skb 0x%p, skb->len %u, skb->truesize %u", skb, skb->len, skb->truesize);
+
+ vcc->push (vcc, skb);
+
+ vcc_data->skb = NULL;
 
- /* update stats */
- atomic_inc (&ctx->vcc->stats->rx);
+ continue;
 
- vdbg ("udsl_decode_aal5 returns pdu 0x%p with length %d", skb, skb->len);
- return skb;
+drop:
+ atomic_inc (&vcc->stats->rx_err);
+drop_no_stats:
+ skb_trim (skb, 0);
+ }
+ }
 }
 
 
@@ -500,145 +484,89 @@
 
 static void udsl_complete_receive (struct urb *urb, struct pt_regs *regs)
 {
+ struct udsl_receive_buffer *buf;
         struct udsl_instance_data *instance;
         struct udsl_receiver *rcv;
         unsigned long flags;
 
- if (!urb || !(rcv = urb->context) || !(instance = rcv->instance)) {
+ if (!urb || !(rcv = urb->context)) {
                 dbg ("udsl_complete_receive: bad urb!");
                 return;
         }
 
- vdbg ("udsl_complete_receive entered (urb 0x%p, status %d)", urb, urb->status);
+ instance = rcv->instance;
+ buf = rcv->buffer;
+
+ buf->filled_cells = urb->actual_length / ATM_CELL_SIZE;
+
+ vdbg ("udsl_complete_receive: urb 0x%p, status %d, actual_length %d, filled_cells %u, rcv 0x%p, buf 0x%p", urb, urb->status, urb->actual_length, buf->filled_cells, rcv, buf);
+
+ BUG_ON (buf->filled_cells > UDSL_RCV_BUF_SIZE);
 
         /* may not be in_interrupt() */
- spin_lock_irqsave (&instance->completed_receivers_lock, flags);
- list_add_tail (&rcv->list, &instance->completed_receivers);
- tasklet_schedule (&instance->receive_tasklet);
- spin_unlock_irqrestore (&instance->completed_receivers_lock, flags);
+ spin_lock_irqsave (&instance->receive_lock, flags);
+ list_add (&rcv->list, &instance->spare_receivers);
+ list_add_tail (&buf->list, &instance->filled_receive_buffers);
+ if (likely (!urb->status))
+ tasklet_schedule (&instance->receive_tasklet);
+ spin_unlock_irqrestore (&instance->receive_lock, flags);
 }
 
 static void udsl_process_receive (unsigned long data)
 {
+ struct udsl_receive_buffer *buf;
         struct udsl_instance_data *instance = (struct udsl_instance_data *) data;
         struct udsl_receiver *rcv;
- unsigned char *data_start;
- struct sk_buff *skb;
- struct urb *urb;
- struct udsl_vcc_data *atmsar_vcc = NULL;
- struct sk_buff *new = NULL, *tmp = NULL;
         int err;
 
- vdbg ("udsl_process_receive entered");
-
- spin_lock_irq (&instance->completed_receivers_lock);
- while (!list_empty (&instance->completed_receivers)) {
- rcv = list_entry (instance->completed_receivers.next, struct udsl_receiver, list);
- list_del (&rcv->list);
- spin_unlock_irq (&instance->completed_receivers_lock);
-
- urb = rcv->urb;
- vdbg ("udsl_process_receive: got packet %p with length %d and status %d", urb, urb->actual_length, urb->status);
-
- switch (urb->status) {
- case 0:
- vdbg ("udsl_process_receive: processing urb with rcv %p, urb %p, skb %p", rcv, urb, rcv->skb);
-
- /* update the skb structure */
- skb = rcv->skb;
- skb_trim (skb, 0);
- skb_put (skb, urb->actual_length);
- data_start = skb->data;
-
- vdbg ("skb->len = %d", skb->len);
- PACKETDEBUG (skb->data, skb->len);
-
- while ((new = udsl_decode_rawcell (instance, skb, &atmsar_vcc))) {
- vdbg ("(after cell processing)skb->len = %d", new->len);
-
- tmp = new;
- new = udsl_decode_aal5 (atmsar_vcc, new);
-
- /* we can't send NULL skbs upstream, the ATM layer would try to close the vcc... */
- if (new) {
- vdbg ("(after aal5 decap) skb->len = %d", new->len);
- if (new->len && atm_charge (atmsar_vcc->vcc, new->truesize)) {
- PACKETDEBUG (new->data, new->len);
- atmsar_vcc->vcc->push (atmsar_vcc->vcc, new);
- } else {
- dbg
- ("dropping incoming packet : vcc->sk->rcvbuf = %d, skb->true_size = %d",
- atmsar_vcc->vcc->sk->rcvbuf, new->truesize);
- dev_kfree_skb (new);
- }
- } else {
- dbg ("udsl_decode_aal5 returned NULL!");
- dev_kfree_skb (tmp);
- }
- }
-
- /* restore skb */
- skb_push (skb, skb->data - data_start);
-
- usb_fill_bulk_urb (urb,
- instance->usb_dev,
- usb_rcvbulkpipe (instance->usb_dev, UDSL_ENDPOINT_DATA_IN),
- (unsigned char *) rcv->skb->data,
- UDSL_RCV_BUF_SIZE * ATM_CELL_SIZE,
- udsl_complete_receive,
- rcv);
- if (!(err = usb_submit_urb (urb, GFP_ATOMIC)))
- break;
- dbg ("udsl_process_receive: submission failed (%d)", err);
- /* fall through */
- default: /* error or urb unlinked */
- vdbg ("udsl_process_receive: adding to spare_receivers");
- spin_lock_irq (&instance->spare_receivers_lock);
- list_add (&rcv->list, &instance->spare_receivers);
- spin_unlock_irq (&instance->spare_receivers_lock);
+made_progress:
+ while (!list_empty (&instance->spare_receive_buffers)) {
+ spin_lock_irq (&instance->receive_lock);
+ if (list_empty (&instance->spare_receivers)) {
+ spin_unlock_irq (&instance->receive_lock);
                         break;
- } /* switch */
-
- spin_lock_irq (&instance->completed_receivers_lock);
- } /* while */
- spin_unlock_irq (&instance->completed_receivers_lock);
- vdbg ("udsl_process_receive successful");
-}
-
-static void udsl_fire_receivers (struct udsl_instance_data *instance)
-{
- struct list_head receivers, *pos, *n;
-
- INIT_LIST_HEAD (&receivers);
-
- down (&instance->serialize);
-
- spin_lock_irq (&instance->spare_receivers_lock);
- list_splice_init (&instance->spare_receivers, &receivers);
- spin_unlock_irq (&instance->spare_receivers_lock);
+ }
+ rcv = list_entry (instance->spare_receivers.next, struct udsl_receiver, list);
+ list_del (&rcv->list);
+ spin_unlock_irq (&instance->receive_lock);
 
- list_for_each_safe (pos, n, &receivers) {
- struct udsl_receiver *rcv = list_entry (pos, struct udsl_receiver, list);
+ buf = list_entry (instance->spare_receive_buffers.next, struct udsl_receive_buffer, list);
+ list_del (&buf->list);
 
- dbg ("udsl_fire_receivers: firing urb %p", rcv->urb);
+ rcv->buffer = buf;
 
                 usb_fill_bulk_urb (rcv->urb,
                                    instance->usb_dev,
                                    usb_rcvbulkpipe (instance->usb_dev, UDSL_ENDPOINT_DATA_IN),
- (unsigned char *) rcv->skb->data,
+ buf->base,
                                    UDSL_RCV_BUF_SIZE * ATM_CELL_SIZE,
                                    udsl_complete_receive,
                                    rcv);
 
- if (usb_submit_urb (rcv->urb, GFP_KERNEL) < 0) {
- dbg ("udsl_fire_receivers: submit failed!");
- spin_lock_irq (&instance->spare_receivers_lock);
- list_move (pos, &instance->spare_receivers);
- spin_unlock_irq (&instance->spare_receivers_lock);
+ vdbg ("udsl_process_receive: sending urb 0x%p, rcv 0x%p, buf 0x%p", rcv->urb, rcv, buf);
+
+ if ((err = usb_submit_urb(rcv->urb, GFP_ATOMIC)) < 0) {
+ dbg ("udsl_process_receive: urb submission failed (%d)!", err);
+ list_add (&buf->list, &instance->spare_receive_buffers);
+ spin_lock_irq (&instance->receive_lock);
+ list_add (&rcv->list, &instance->spare_receivers);
+ spin_unlock_irq (&instance->receive_lock);
+ break;
                 }
         }
 
- up (&instance->serialize);
+ spin_lock_irq (&instance->receive_lock);
+ if (list_empty (&instance->filled_receive_buffers)) {
+ spin_unlock_irq (&instance->receive_lock);
+ return; /* done - no more buffers */
+ }
+ buf = list_entry (instance->filled_receive_buffers.next, struct udsl_receive_buffer, list);
+ list_del (&buf->list);
+ spin_unlock_irq (&instance->receive_lock);
+ vdbg ("udsl_process_receive: processing buf 0x%p", buf);
+ udsl_extract_cells (instance, buf->base, buf->filled_cells);
+ list_add (&buf->list, &instance->spare_receive_buffers);
+ goto made_progress;
 }
 
 
@@ -839,6 +767,7 @@
 
         dbg ("udsl_atm_dev_close: queue has %u elements", instance->sndqueue.qlen);
 
+ tasklet_kill (&instance->receive_tasklet);
         tasklet_kill (&instance->send_tasklet);
         kfree (instance);
         dev->dev_data = NULL;
@@ -913,7 +842,7 @@
                 return -EINVAL;
 
         /* only support AAL5 */
- if (vcc->qos.aal != ATM_AAL5 || vcc->qos.rxtp.max_sdu < 0 || vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU)
+ if ((vcc->qos.aal != ATM_AAL5) || (vcc->qos.rxtp.max_sdu < 0) || (vcc->qos.rxtp.max_sdu > ATM_MAX_AAL5_PDU))
                 return -EINVAL;
 
         if (!instance->firmware_loaded) {
@@ -953,7 +882,7 @@
 
         up (&instance->serialize);
 
- udsl_fire_receivers (instance);
+ tasklet_schedule (&instance->receive_tasklet);
 
         dbg ("udsl_atm_open: allocated vcc data 0x%p (max_pdu: %u)", new, new->max_pdu);
 
@@ -1029,7 +958,9 @@
                 instance->firmware_loaded = 1;
         }
         up (&instance->serialize);
- udsl_fire_receivers (instance);
+
+ tasklet_schedule (&instance->receive_tasklet);
+
         return 0;
 }
 
@@ -1089,13 +1020,12 @@
 
         INIT_LIST_HEAD (&instance->vcc_list);
 
- spin_lock_init (&instance->spare_receivers_lock);
+ spin_lock_init (&instance->receive_lock);
         INIT_LIST_HEAD (&instance->spare_receivers);
-
- spin_lock_init (&instance->completed_receivers_lock);
- INIT_LIST_HEAD (&instance->completed_receivers);
+ INIT_LIST_HEAD (&instance->filled_receive_buffers);
 
         tasklet_init (&instance->receive_tasklet, udsl_process_receive, (unsigned long) instance);
+ INIT_LIST_HEAD (&instance->spare_receive_buffers);
 
         skb_queue_head_init (&instance->sndqueue);
 
@@ -1110,11 +1040,6 @@
         for (i = 0; i < UDSL_NUM_RCV_URBS; i++) {
                 struct udsl_receiver *rcv = &(instance->receivers [i]);
 
- if (!(rcv->skb = dev_alloc_skb (UDSL_RCV_BUF_SIZE * ATM_CELL_SIZE))) {
- dbg ("udsl_usb_probe: no memory for skb %d!", i);
- goto fail;
- }
-
                 if (!(rcv->urb = usb_alloc_urb (0, GFP_KERNEL))) {
                         dbg ("udsl_usb_probe: no memory for receive urb %d!", i);
                         goto fail;
@@ -1123,8 +1048,17 @@
                 rcv->instance = instance;
 
                 list_add (&rcv->list, &instance->spare_receivers);
+ }
 
- dbg ("udsl_usb_probe: skb->truesize = %d (asked for %d)", rcv->skb->truesize, UDSL_RCV_BUF_SIZE * ATM_CELL_SIZE);
+ for (i = 0; i < UDSL_NUM_RCV_BUFS; i++) {
+ struct udsl_receive_buffer *buf = &(instance->receive_buffers [i]);
+
+ if (!(buf->base = kmalloc (UDSL_RCV_BUF_SIZE * ATM_CELL_SIZE, GFP_KERNEL))) {
+ dbg ("udsl_usb_probe: no memory for receive buffer %d!", i);
+ goto fail;
+ }
+
+ list_add (&buf->list, &instance->spare_receive_buffers);
         }
 
         /* send init */
@@ -1209,14 +1143,11 @@
         for (i = 0; i < UDSL_NUM_SND_URBS; i++)
                 usb_free_urb (instance->senders [i].urb);
 
- for (i = 0; i < UDSL_NUM_RCV_URBS; i++) {
- struct udsl_receiver *rcv = &(instance->receivers [i]);
-
- usb_free_urb (rcv->urb);
+ for (i = 0; i < UDSL_NUM_RCV_BUFS; i++)
+ kfree (instance->receive_buffers [i].base);
 
- if (rcv->skb)
- dev_kfree_skb (rcv->skb);
- }
+ for (i = 0; i < UDSL_NUM_RCV_URBS; i++)
+ usb_free_urb (instance->receivers [i].urb);
 
         kfree (instance);
 
@@ -1227,7 +1158,7 @@
 {
         struct udsl_instance_data *instance = usb_get_intfdata (intf);
         struct list_head *pos;
- unsigned int count = 0;
+ unsigned int count;
         int result, i;
 
         dbg ("udsl_usb_disconnect entered");
@@ -1239,20 +1170,8 @@
                 return;
         }
 
- tasklet_disable (&instance->receive_tasklet);
-
         /* receive finalize */
- down (&instance->serialize); /* vs udsl_fire_receivers */
- /* no need to take the spinlock */
- list_for_each (pos, &instance->spare_receivers)
- if (++count > UDSL_NUM_RCV_URBS)
- panic (__FILE__ ": memory corruption detected at line %d!\n", __LINE__);
- INIT_LIST_HEAD (&instance->spare_receivers);
- up (&instance->serialize);
-
- dbg ("udsl_usb_disconnect: flushed %u spare receivers", count);
-
- count = UDSL_NUM_RCV_URBS - count;
+ tasklet_disable (&instance->receive_tasklet);
 
         for (i = 0; i < UDSL_NUM_RCV_URBS; i++)
                 if ((result = usb_unlink_urb (instance->receivers [i].urb)) < 0)
@@ -1260,17 +1179,16 @@
 
         /* wait for completion handlers to finish */
         do {
- unsigned int completed = 0;
-
- spin_lock_irq (&instance->completed_receivers_lock);
- list_for_each (pos, &instance->completed_receivers)
- if (++completed > count)
+ count = 0;
+ spin_lock_irq (&instance->receive_lock);
+ list_for_each (pos, &instance->spare_receivers)
+ if (++count > UDSL_NUM_RCV_URBS)
                                 panic (__FILE__ ": memory corruption detected at line %d!\n", __LINE__);
- spin_unlock_irq (&instance->completed_receivers_lock);
+ spin_unlock_irq (&instance->receive_lock);
 
- dbg ("udsl_usb_disconnect: found %u completed receivers", completed);
+ dbg ("udsl_usb_disconnect: found %u spare receivers", count);
 
- if (completed == count)
+ if (count == UDSL_NUM_RCV_URBS)
                         break;
 
                 set_current_state (TASK_RUNNING);
@@ -1278,17 +1196,16 @@
         } while (1);
 
         /* no need to take the spinlock */
- INIT_LIST_HEAD (&instance->completed_receivers);
+ INIT_LIST_HEAD (&instance->filled_receive_buffers);
+ INIT_LIST_HEAD (&instance->spare_receive_buffers);
 
         tasklet_enable (&instance->receive_tasklet);
- tasklet_kill (&instance->receive_tasklet);
 
- for (i = 0; i < UDSL_NUM_RCV_URBS; i++) {
- struct udsl_receiver *rcv = &(instance->receivers [i]);
+ for (i = 0; i < UDSL_NUM_RCV_URBS; i++)
+ usb_free_urb (instance->receivers [i].urb);
 
- usb_free_urb (rcv->urb);
- dev_kfree_skb (rcv->skb);
- }
+ for (i = 0; i < UDSL_NUM_RCV_BUFS; i++)
+ kfree (instance->receive_buffers [i].base);
 
         /* send finalize */
         tasklet_disable (&instance->send_tasklet);
@@ -1332,7 +1249,7 @@
         instance->usb_dev = NULL;
 
         /* ATM finalize */
- shutdown_atm_dev (instance->atm_dev); /* frees instance */
+ shutdown_atm_dev (instance->atm_dev); /* frees instance, kills tasklets */
 }
 
 

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This archive was generated by hypermail 2b29 : Fri May 23 2003 - 22:00:42 EST