On Tue, Apr 18 2017, Jerry Zhang wrote:
> There were individual waitqueues for each epfile but eps_enable
> would iterate through all of them, resulting in essentially the
> same wakeup time.
>
> The waitqueue represents the function being enabled, so a central
> waitqueue in ffs_data makes more sense and is less redundant.
>
> Also use wake_up_interruptible to reflect use of
> wait_event_interruptible.
>
> Signed-off-by: Jerry Zhang <zhangje...@google.com>
Acked-by: Michal Nazarewicz <min...@mina86.com>
> ---
> drivers/usb/gadget/function/f_fs.c | 19 ++++++++++---------
> drivers/usb/gadget/function/u_fs.h | 3 +++
> 2 files changed, 13 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/usb/gadget/function/f_fs.c
> b/drivers/usb/gadget/function/f_fs.c
> index 48de9e013ba8..0abb2e14eb9a 100644
> --- a/drivers/usb/gadget/function/f_fs.c
> +++ b/drivers/usb/gadget/function/f_fs.c
> @@ -127,7 +127,6 @@ struct ffs_ep {
> struct ffs_epfile {
> /* Protects ep->ep and ep->req. */
> struct mutex mutex;
> - wait_queue_head_t wait;
>
> struct ffs_data *ffs;
> struct ffs_ep *ep; /* P: ffs->eps_lock */
> @@ -890,7 +889,8 @@ static ssize_t ffs_epfile_io(struct file *file, struct
> ffs_io_data *io_data)
> if (file->f_flags & O_NONBLOCK)
> return -EAGAIN;
>
> - ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
> + ret = wait_event_interruptible(
> + epfile->ffs->wait, (ep = epfile->ep));
> if (ret)
> return -EINTR;
> }
> @@ -1204,7 +1204,8 @@ static long ffs_epfile_ioctl(struct file *file,
> unsigned code,
> if (file->f_flags & O_NONBLOCK)
> return -EAGAIN;
>
> - ret = wait_event_interruptible(epfile->wait, (ep = epfile->ep));
> + ret = wait_event_interruptible(
> + epfile->ffs->wait, (ep = epfile->ep));
> if (ret)
> return -EINTR;
> }
> @@ -1602,7 +1603,8 @@ static void ffs_data_put(struct ffs_data *ffs)
> pr_info("%s(): freeing\n", __func__);
> ffs_data_clear(ffs);
> BUG_ON(waitqueue_active(&ffs->ev.waitq) ||
> - waitqueue_active(&ffs->ep0req_completion.wait));
> + waitqueue_active(&ffs->ep0req_completion.wait) ||
> + waitqueue_active(&ffs->wait));
> kfree(ffs->dev_name);
> kfree(ffs);
> }
> @@ -1649,6 +1651,7 @@ static struct ffs_data *ffs_data_new(void)
> mutex_init(&ffs->mutex);
> spin_lock_init(&ffs->eps_lock);
> init_waitqueue_head(&ffs->ev.waitq);
> + init_waitqueue_head(&ffs->wait);
> init_completion(&ffs->ep0req_completion);
>
> /* XXX REVISIT need to update it in some places, or do we? */
> @@ -1770,7 +1773,6 @@ static int ffs_epfiles_create(struct ffs_data *ffs)
> for (i = 1; i <= count; ++i, ++epfile) {
> epfile->ffs = ffs;
> mutex_init(&epfile->mutex);
> - init_waitqueue_head(&epfile->wait);
> if (ffs->user_flags & FUNCTIONFS_VIRTUAL_ADDR)
> sprintf(epfile->name, "ep%02x", ffs->eps_addrmap[i]);
> else
> @@ -1795,8 +1797,7 @@ static void ffs_epfiles_destroy(struct ffs_epfile
> *epfiles, unsigned count)
> ENTER();
>
> for (; count; --count, ++epfile) {
> - BUG_ON(mutex_is_locked(&epfile->mutex) ||
> - waitqueue_active(&epfile->wait));
> + BUG_ON(mutex_is_locked(&epfile->mutex));
> if (epfile->dentry) {
> d_delete(epfile->dentry);
> dput(epfile->dentry);
> @@ -1883,11 +1884,11 @@ static int ffs_func_eps_enable(struct ffs_function
> *func)
> break;
> }
>
> - wake_up(&epfile->wait);
> -
> ++ep;
> ++epfile;
> }
> +
> + wake_up_interruptible(&ffs->wait);
> spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
>
> return ret;
> diff --git a/drivers/usb/gadget/function/u_fs.h
> b/drivers/usb/gadget/function/u_fs.h
> index 4b6969451cdc..052ea89c7f99 100644
> --- a/drivers/usb/gadget/function/u_fs.h
> +++ b/drivers/usb/gadget/function/u_fs.h
> @@ -214,6 +214,9 @@ struct ffs_data {
> #define FFS_FL_CALL_CLOSED_CALLBACK 0
> #define FFS_FL_BOUND 1
>
> + /* For waking up blocked threads when function is enabled. */
> + wait_queue_head_t wait;
> +
> /* Active function */
> struct ffs_function *func;
--
Best regards
ミハウ “𝓶𝓲𝓷𝓪86” ナザレヴイツ
«If at first you don’t succeed, give up skydiving»
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