static struct mon_event_text *mon_text_read_wait(struct mon_reader_text *rp,
struct file *file)
{
struct mon_bus *mbus = rp->r.m_bus;
DECLARE_WAITQUEUE(waita, current);
struct mon_event_text *ep;
add_wait_queue(&rp->wait, &waita);
set_current_state(TASK_INTERRUPTIBLE);
while ((ep = mon_text_fetch(rp, mbus)) == NULL) {
if (file->f_flags & O_NONBLOCK) {
set_current_state(TASK_RUNNING);
remove_wait_queue(&rp->wait, &waita);
return ERR_PTR(-EWOULDBLOCK);
}
/*
* We do not count nwaiters, because ->release is supposed
* to be called when all openers are gone only.
*/
schedule();
if (signal_pending(current)) {
remove_wait_queue(&rp->wait, &waita);
return ERR_PTR(-EINTR);
}
set_current_state(TASK_INTERRUPTIBLE);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&rp->wait, &waita);
return ep;
}
/*
* For simplicity, we read one record in one system call and throw out
* what does not fit. This means that the following does not work:
* dd if=/dbg/usbmon/0t bs=10
* Also, we do not allow seeks and do not bother advancing the offset.
*/
static ssize_t mon_text_read(struct file *file, char __user *buf,
size_t nbytes, loff_t *ppos)
{
struct mon_reader_text *rp = file->private_data;
struct mon_bus *mbus = rp->r.m_bus;
DECLARE_WAITQUEUE(waita, current);
struct mon_event_text *ep;
int cnt, limit;
char *pbuf;
char udir, utype;
int data_len, i;
add_wait_queue(&rp->wait, &waita);
set_current_state(TASK_INTERRUPTIBLE);
while ((ep = mon_text_fetch(rp, mbus)) == NULL) {
if (file->f_flags & O_NONBLOCK) {
set_current_state(TASK_RUNNING);
remove_wait_queue(&rp->wait, &waita);
return -EWOULDBLOCK; /* Same as EAGAIN in Linux */
}
/*
* We do not count nwaiters, because ->release is supposed
* to be called when all openers are gone only.
*/
schedule();
if (signal_pending(current)) {
remove_wait_queue(&rp->wait, &waita);
return -EINTR;
}
set_current_state(TASK_INTERRUPTIBLE);
}
set_current_state(TASK_RUNNING);
remove_wait_queue(&rp->wait, &waita);
down(&rp->printf_lock);
cnt = 0;
pbuf = rp->printf_buf;
limit = rp->printf_size;
udir = usb_pipein(ep->pipe) ? 'i' : 'o';
switch (usb_pipetype(ep->pipe)) {
case PIPE_ISOCHRONOUS: utype = 'Z'; break;
case PIPE_INTERRUPT: utype = 'I'; break;
case PIPE_CONTROL: utype = 'C'; break;
default: /* PIPE_BULK */ utype = 'B';
}
cnt += snprintf(pbuf + cnt, limit - cnt,
"%lx %u %c %c%c:%03u:%02u",
ep->id, ep->tstamp, ep->type,
utype, udir, usb_pipedevice(ep->pipe), usb_pipeendpoint(ep->pipe));
if (ep->setup_flag == 0) { /* Setup packet is present and captured */
cnt += snprintf(pbuf + cnt, limit - cnt,
" s %02x %02x %04x %04x %04x",
ep->setup[0],
ep->setup[1],
(ep->setup[3] << 8) | ep->setup[2],
(ep->setup[5] << 8) | ep->setup[4],
(ep->setup[7] << 8) | ep->setup[6]);
} else if (ep->setup_flag != '-') { /* Unable to capture setup packet */
cnt += snprintf(pbuf + cnt, limit - cnt,
" %c __ __ ____ ____ ____", ep->setup_flag);
} else { /* No setup for this kind of URB */
cnt += snprintf(pbuf + cnt, limit - cnt, " %d", ep->status);
}
cnt += snprintf(pbuf + cnt, limit - cnt, " %d", ep->length);
if ((data_len = ep->length) > 0) {
if (ep->data_flag == 0) {
cnt += snprintf(pbuf + cnt, limit - cnt, " =");
if (data_len >= DATA_MAX)
data_len = DATA_MAX;
for (i = 0; i < data_len; i++) {
if (i % 4 == 0) {
cnt += snprintf(pbuf + cnt, limit - cnt,
" ");
}
cnt += snprintf(pbuf + cnt, limit - cnt,
"%02x", ep->data[i]);
}
cnt += snprintf(pbuf + cnt, limit - cnt, "\n");
} else {
cnt += snprintf(pbuf + cnt, limit - cnt,
" %c\n", ep->data_flag);
}
} else {
cnt += snprintf(pbuf + cnt, limit - cnt, "\n");
}
if (copy_to_user(buf, rp->printf_buf, cnt))
cnt = -EFAULT;
up(&rp->printf_lock);
kmem_cache_free(rp->e_slab, ep);
return cnt;
}
