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USB: autosuspend for usblcd
this patch implements autosuspend for the usblcd driver. It uses the new usb_anchor infrastructure. Many thanks to Georges for testing. Signed-off-by: Oliver Neukum <oneukum@suse.de> Cc: Georges Toth <g.toth@e-biz.lu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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parent
55b3fd41b0
commit
7bbe990c98
1 changed files with 43 additions and 3 deletions
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@ -45,6 +45,7 @@ struct usb_lcd {
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struct kref kref;
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struct semaphore limit_sem; /* to stop writes at full throttle from
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* using up all RAM */
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struct usb_anchor submitted; /* URBs to wait for before suspend */
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};
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#define to_lcd_dev(d) container_of(d, struct usb_lcd, kref)
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@ -67,7 +68,7 @@ static int lcd_open(struct inode *inode, struct file *file)
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{
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struct usb_lcd *dev;
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struct usb_interface *interface;
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int subminor;
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int subminor, r;
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subminor = iminor(inode);
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@ -85,6 +86,13 @@ static int lcd_open(struct inode *inode, struct file *file)
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/* increment our usage count for the device */
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kref_get(&dev->kref);
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/* grab a power reference */
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r = usb_autopm_get_interface(interface);
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if (r < 0) {
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kref_put(&dev->kref, lcd_delete);
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return r;
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}
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/* save our object in the file's private structure */
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file->private_data = dev;
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@ -100,6 +108,7 @@ static int lcd_release(struct inode *inode, struct file *file)
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return -ENODEV;
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/* decrement the count on our device */
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usb_autopm_put_interface(dev->interface);
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kref_put(&dev->kref, lcd_delete);
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return 0;
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}
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@ -225,12 +234,14 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer, siz
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usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr),
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buf, count, lcd_write_bulk_callback, dev);
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urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
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usb_anchor_urb(urb, &dev->submitted);
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/* send the data out the bulk port */
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retval = usb_submit_urb(urb, GFP_KERNEL);
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if (retval) {
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err("USBLCD: %s - failed submitting write urb, error %d", __FUNCTION__, retval);
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goto error;
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goto error_unanchor;
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}
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/* release our reference to this urb, the USB core will eventually free it entirely */
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@ -238,7 +249,8 @@ static ssize_t lcd_write(struct file *file, const char __user * user_buffer, siz
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exit:
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return count;
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error_unanchor:
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usb_unanchor_urb(urb);
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error:
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usb_buffer_free(dev->udev, count, buf, urb->transfer_dma);
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usb_free_urb(urb);
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@ -283,6 +295,7 @@ static int lcd_probe(struct usb_interface *interface, const struct usb_device_id
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}
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kref_init(&dev->kref);
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sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
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init_usb_anchor(&dev->submitted);
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dev->udev = usb_get_dev(interface_to_usbdev(interface));
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dev->interface = interface;
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@ -350,6 +363,30 @@ static int lcd_probe(struct usb_interface *interface, const struct usb_device_id
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return retval;
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}
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static void lcd_draw_down(struct usb_lcd *dev)
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{
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int time;
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time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000);
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if (!time)
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usb_kill_anchored_urbs(&dev->submitted);
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}
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static int lcd_suspend(struct usb_interface *intf, pm_message_t message)
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{
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struct usb_lcd *dev = usb_get_intfdata(intf);
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if (!dev)
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return 0;
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lcd_draw_down(dev);
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return 0;
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}
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static int lcd_resume (struct usb_interface *intf)
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{
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return 0;
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}
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static void lcd_disconnect(struct usb_interface *interface)
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{
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struct usb_lcd *dev;
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@ -371,7 +408,10 @@ static struct usb_driver lcd_driver = {
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.name = "usblcd",
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.probe = lcd_probe,
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.disconnect = lcd_disconnect,
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.suspend = lcd_suspend,
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.resume = lcd_resume,
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.id_table = id_table,
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.supports_autosuspend = 1,
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};
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static int __init usb_lcd_init(void)
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