staging: gpib: Replace semaphore with completion for one-time signaling

Replaced 'down_interruptible()' and 'up()' calls
with 'wait_for_completion_interruptible()' and
'complete()' respectively. The completion API
simplifies the code and adheres to kernel best
practices for synchronization primitive

Signed-off-by: Santosh Mahto <eisantosh95@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20241212162112.13083-1-eisantosh95@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
index b7b6fb1be379032b894e2b0cb7d0325c83bf4b07..70b8b305e13b6b4fdd3334973eb1e8bc8af91533 100644 (file)
--- a/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
+++ b/drivers/staging/gpib/ni_usb/ni_usb_gpib.c
@@ -85,7 +85,7 @@ static void ni_usb_bulk_complete(struct urb *urb)
 
 //     printk("debug: %s: status=0x%x, error_count=%i, actual_length=%i\n",  __func__,
 //             urb->status, urb->error_count, urb->actual_length);
-       up(&context->complete);
+       complete(&context->complete);
 }
 
 static void ni_usb_timeout_handler(struct timer_list *t)
@@ -94,7 +94,7 @@ static void ni_usb_timeout_handler(struct timer_list *t)
        struct ni_usb_urb_ctx *context = &ni_priv->context;
 
        context->timed_out = 1;
-       up(&context->complete);
+       complete(&context->complete);
 };
 
 // I'm using nonblocking loosely here, it only means -EAGAIN can be returned in certain cases
@@ -124,7 +124,7 @@ static int ni_usb_nonblocking_send_bulk_msg(struct ni_usb_priv *ni_priv, void *d
        }
        usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        out_pipe = usb_sndbulkpipe(usb_dev, ni_priv->bulk_out_endpoint);
-       sema_init(&context->complete, 0);
+       init_completion(&context->complete);
        context->timed_out = 0;
        usb_fill_bulk_urb(ni_priv->bulk_urb, usb_dev, out_pipe, data, data_length,
                          &ni_usb_bulk_complete, context);
@@ -143,7 +143,7 @@ static int ni_usb_nonblocking_send_bulk_msg(struct ni_usb_priv *ni_priv, void *d
                return retval;
        }
        mutex_unlock(&ni_priv->bulk_transfer_lock);
-       down(&context->complete);    // wait for ni_usb_bulk_complete
+       wait_for_completion(&context->complete);    // wait for ni_usb_bulk_complete
        if (context->timed_out) {
                usb_kill_urb(ni_priv->bulk_urb);
                dev_err(&usb_dev->dev, "%s: killed urb due to timeout\n", __func__);
@@ -210,7 +210,7 @@ static int ni_usb_nonblocking_receive_bulk_msg(struct ni_usb_priv *ni_priv,
        }
        usb_dev = interface_to_usbdev(ni_priv->bus_interface);
        in_pipe = usb_rcvbulkpipe(usb_dev, ni_priv->bulk_in_endpoint);
-       sema_init(&context->complete, 0);
+       init_completion(&context->complete);
        context->timed_out = 0;
        usb_fill_bulk_urb(ni_priv->bulk_urb, usb_dev, in_pipe, data, data_length,
                          &ni_usb_bulk_complete, context);
@@ -231,7 +231,7 @@ static int ni_usb_nonblocking_receive_bulk_msg(struct ni_usb_priv *ni_priv,
        }
        mutex_unlock(&ni_priv->bulk_transfer_lock);
        if (interruptible) {
-               if (down_interruptible(&context->complete)) {
+               if (wait_for_completion_interruptible(&context->complete)) {
                        /* If we got interrupted by a signal while
                         * waiting for the usb gpib to respond, we
                         * should send a stop command so it will
@@ -243,10 +243,10 @@ static int ni_usb_nonblocking_receive_bulk_msg(struct ni_usb_priv *ni_priv,
                        /* now do an uninterruptible wait, it shouldn't take long
                         *      for the board to respond now.
                         */
-                       down(&context->complete);
+                       wait_for_completion(&context->complete);
                }
        } else {
-               down(&context->complete);
+               wait_for_completion(&context->complete);
        }
        if (context->timed_out) {
                usb_kill_urb(ni_priv->bulk_urb);

diff --git a/drivers/staging/gpib/ni_usb/ni_usb_gpib.h b/drivers/staging/gpib/ni_usb/ni_usb_gpib.h
index 9b21dfa0f3f6d12480a86bdf3a9ecade24eaeb8a..4b297db09a9bf567e08209764bfe0eab7c2ad621 100644 (file)
--- a/drivers/staging/gpib/ni_usb/ni_usb_gpib.h
+++ b/drivers/staging/gpib/ni_usb/ni_usb_gpib.h
@@ -56,7 +56,7 @@ enum hs_plus_endpoint_addresses {
 };
 
 struct ni_usb_urb_ctx {
-       struct semaphore complete;
+       struct completion complete;
        unsigned timed_out : 1;
 };