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usb: gadget: f_fs: remove loop from I/O function

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When endpoint changes (due to it being disabled or alt setting changed),
mimic the action as if the change happened after the request has been
queued, instead of retrying with the new endpoint.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Cc: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This commit is contained in:
Michal Nazarewicz 2013-12-09 15:55:36 -08:00 committed by Felipe Balbi
parent 0b2d2bbade
commit 7fa6803483
1 changed files with 52 additions and 66 deletions
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118
drivers/usb/gadget/f_fs.c
View File

@ -758,73 +758,59 @@ static ssize_t ffs_epfile_io(struct file *file,
ssize_t ret;
int halt;
goto first_try;
do {
/* Are we still active? */
if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
ret = -ENODEV;
goto error;
}
/* Wait for endpoint to be enabled */
ep = epfile->ep;
if (!ep) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
goto error;
}
ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
if (ret) {
ret = -EINTR;
goto error;
}
}
/* Do we halt? */
halt = !read == !epfile->in;
if (halt && epfile->isoc) {
ret = -EINVAL;
goto error;
}
/* Allocate & copy */
if (!halt) {
data = kmalloc(len, GFP_KERNEL);
if (unlikely(!data))
return -ENOMEM;
if (!read && unlikely(copy_from_user(data, buf, len))) {
ret = -EFAULT;
goto error;
}
}
/* We will be using request */
ret = ffs_mutex_lock(&epfile->mutex, file->f_flags & O_NONBLOCK);
if (unlikely(ret))
goto error;
spin_lock_irq(&epfile->ffs->eps_lock);
if (epfile->ep != ep) {
/* In the meantime, endpoint got disabled or changed. */
ret = -ESHUTDOWN;
spin_unlock_irq(&epfile->ffs->eps_lock);
mutex_unlock(&epfile->mutex);
first_try:
/* Are we still active? */
if (WARN_ON(epfile->ffs->state != FFS_ACTIVE)) {
ret = -ENODEV;
goto error;
}
/* Wait for endpoint to be enabled */
ep = epfile->ep;
if (!ep) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
goto error;
}
if (wait_event_interruptible(epfile->wait,
(ep = epfile->ep))) {
ret = -EINTR;
goto error;
}
}
/* Do we halt? */
halt = !read == !epfile->in;
if (halt && epfile->isoc) {
ret = -EINVAL;
goto error;
}
/* Allocate & copy */
if (!halt && !data) {
data = kzalloc(len, GFP_KERNEL);
if (unlikely(!data))
return -ENOMEM;
if (!read &&
unlikely(__copy_from_user(data, buf, len))) {
ret = -EFAULT;
goto error;
}
}
/* We will be using request */
ret = ffs_mutex_lock(&epfile->mutex,
file->f_flags & O_NONBLOCK);
if (unlikely(ret))
goto error;
/*
* We're called from user space, we can use _irq rather then
* _irqsave
*/
spin_lock_irq(&epfile->ffs->eps_lock);
/*
* While we were acquiring mutex endpoint got disabled
* or changed?
*/
} while (unlikely(epfile->ep != ep));
/* Halt */
if (unlikely(halt)) {
} else if (halt) {
/* Halt */
if (likely(epfile->ep == ep) && !WARN_ON(!ep->ep))
usb_ep_set_halt(ep->ep);
spin_unlock_irq(&epfile->ffs->eps_lock);