const: constify remaining dev_pm_ops

[safe/jmp/linux-2.6] / drivers / usb / usb-skeleton.c

diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index 5ffa3e2..b1e579c 100644 (file)
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -18,7 +18,7 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/kref.h>
-#include <asm/uaccess.h>
+#include <linux/uaccess.h>
 #include <linux/usb.h>
 #include <linux/mutex.h>
 
@@ -28,7 +28,7 @@
 #define USB_SKEL_PRODUCT_ID    0xfff0
 
 /* table of devices that work with this driver */
-static struct usb_device_id skel_table [] = {
+static struct usb_device_id skel_table[] = {
        { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) },
        { }                                     /* Terminating entry */
 };
@@ -94,7 +94,7 @@ static int skel_open(struct inode *inode, struct file *file)
 
        interface = usb_find_interface(&skel_driver, subminor);
        if (!interface) {
-               err ("%s - error, can't find device for minor %d",
+               err("%s - error, can't find device for minor %d",
                     __func__, subminor);
                retval = -ENODEV;
                goto exit;
@@ -190,7 +190,7 @@ static void skel_read_bulk_callback(struct urb *urb)
        spin_lock(&dev->err_lock);
        /* sync/async unlink faults aren't errors */
        if (urb->status) {
-               if(!(urb->status == -ENOENT ||
+               if (!(urb->status == -ENOENT ||
                    urb->status == -ECONNRESET ||
                    urb->status == -ESHUTDOWN))
                        err("%s - nonzero write bulk status received: %d",
@@ -239,7 +239,8 @@ static int skel_do_read_io(struct usb_skel *dev, size_t count)
        return rv;
 }
 
-static ssize_t skel_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
+static ssize_t skel_read(struct file *file, char *buffer, size_t count,
+                        loff_t *ppos)
 {
        struct usb_skel *dev;
        int rv;
@@ -268,6 +269,11 @@ retry:
        spin_unlock_irq(&dev->err_lock);
 
        if (ongoing_io) {
+               /* nonblocking IO shall not wait */
+               if (file->f_flags & O_NONBLOCK) {
+                       rv = -EAGAIN;
+                       goto exit;
+               }
                /*
                 * IO may take forever
                 * hence wait in an interruptible state
@@ -294,7 +300,8 @@ retry:
        }
 
        /* errors must be reported */
-       if ((rv = dev->errors) < 0) {
+       rv = dev->errors;
+       if (rv < 0) {
                /* any error is reported once */
                dev->errors = 0;
                /* to preserve notifications about reset */
@@ -351,8 +358,9 @@ retry:
                rv = skel_do_read_io(dev, count);
                if (rv < 0)
                        goto exit;
-               else
+               else if (!(file->f_flags & O_NONBLOCK))
                        goto retry;
+               rv = -EAGAIN;
        }
 exit:
        mutex_unlock(&dev->io_mutex);
@@ -367,7 +375,7 @@ static void skel_write_bulk_callback(struct urb *urb)
 
        /* sync/async unlink faults aren't errors */
        if (urb->status) {
-               if(!(urb->status == -ENOENT ||
+               if (!(urb->status == -ENOENT ||
                    urb->status == -ECONNRESET ||
                    urb->status == -ESHUTDOWN))
                        err("%s - nonzero write bulk status received: %d",
@@ -384,7 +392,8 @@ static void skel_write_bulk_callback(struct urb *urb)
        up(&dev->limit_sem);
 }
 
-static ssize_t skel_write(struct file *file, const char *user_buffer, size_t count, loff_t *ppos)
+static ssize_t skel_write(struct file *file, const char *user_buffer,
+                         size_t count, loff_t *ppos)
 {
        struct usb_skel *dev;
        int retval = 0;
@@ -398,14 +407,25 @@ static ssize_t skel_write(struct file *file, const char *user_buffer, size_t cou
        if (count == 0)
                goto exit;
 
-       /* limit the number of URBs in flight to stop a user from using up all RAM */
-       if (down_interruptible(&dev->limit_sem)) {
-               retval = -ERESTARTSYS;
-               goto exit;
+       /*
+        * limit the number of URBs in flight to stop a user from using up all
+        * RAM
+        */
+       if (!(file->f_flags & O_NONBLOCK)) {
+               if (down_interruptible(&dev->limit_sem)) {
+                       retval = -ERESTARTSYS;
+                       goto exit;
+               }
+       } else {
+               if (down_trylock(&dev->limit_sem)) {
+                       retval = -EAGAIN;
+                       goto exit;
+               }
        }
 
        spin_lock_irq(&dev->err_lock);
-       if ((retval = dev->errors) < 0) {
+       retval = dev->errors;
+       if (retval < 0) {
                /* any error is reported once */
                dev->errors = 0;
                /* to preserve notifications about reset */
@@ -422,7 +442,8 @@ static ssize_t skel_write(struct file *file, const char *user_buffer, size_t cou
                goto error;
        }
 
-       buf = usb_buffer_alloc(dev->udev, writesize, GFP_KERNEL, &urb->transfer_dma);
+       buf = usb_buffer_alloc(dev->udev, writesize, GFP_KERNEL,
+                              &urb->transfer_dma);
        if (!buf) {
                retval = -ENOMEM;
                goto error;
@@ -452,11 +473,15 @@ static ssize_t skel_write(struct file *file, const char *user_buffer, size_t cou
        retval = usb_submit_urb(urb, GFP_KERNEL);
        mutex_unlock(&dev->io_mutex);
        if (retval) {
-               err("%s - failed submitting write urb, error %d", __func__, retval);
+               err("%s - failed submitting write urb, error %d", __func__,
+                   retval);
                goto error_unanchor;
        }
 
-       /* release our reference to this urb, the USB core will eventually free it entirely */
+       /*
+        * release our reference to this urb, the USB core will eventually free
+        * it entirely
+        */
        usb_free_urb(urb);
 
 
@@ -494,7 +519,8 @@ static struct usb_class_driver skel_class = {
        .minor_base =   USB_SKEL_MINOR_BASE,
 };
 
-static int skel_probe(struct usb_interface *interface, const struct usb_device_id *id)
+static int skel_probe(struct usb_interface *interface,
+                     const struct usb_device_id *id)
 {
        struct usb_skel *dev;
        struct usb_host_interface *iface_desc;
@@ -623,7 +649,7 @@ static int skel_suspend(struct usb_interface *intf, pm_message_t message)
        return 0;
 }
 
-static int skel_resume (struct usb_interface *intf)
+static int skel_resume(struct usb_interface *intf)
 {
        return 0;
 }