w1: ds2490 USB setup fixes
authorDavid Fries <David@Fries.net>
Thu, 16 Jan 2014 04:29:22 +0000 (22:29 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 7 Feb 2014 23:40:18 +0000 (15:40 -0800)
Calling usb_reset_configuration after usb_set_interface resets the
interface that was just selected, so call reset first.
Using alternative 3 greatly speeds the one wire search.
alt 0 or 1, 10ms int, 23.16 seconds
alt 2 or 3,  1ms int, 2.99 to 3.05 seconds

Use usb_interrupt_msg not usb_bulk_msg as it is an interrupt pipe
(bulk worked, it was just technically the wrong call).

Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/w1/masters/ds2490.c

index 6a3d0a1e02b8883762aaf75b62b283bcd3bd679c..cd59e12e8a780e13e4e6cc437e7ef56095c7db59 100644 (file)
@@ -252,7 +252,8 @@ static int ds_recv_status_nodump(struct ds_device *dev, struct ds_status *st,
        memset(st, 0, sizeof(*st));
 
        count = 0;
-       err = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->ep[EP_STATUS]), buf, size, &count, 100);
+       err = usb_interrupt_msg(dev->udev, usb_rcvintpipe(dev->udev,
+               dev->ep[EP_STATUS]), buf, size, &count, 100);
        if (err < 0) {
                printk(KERN_ERR "Failed to read 1-wire data from 0x%x: err=%d.\n", dev->ep[EP_STATUS], err);
                return err;
@@ -917,7 +918,7 @@ static int ds_probe(struct usb_interface *intf,
        struct usb_endpoint_descriptor *endpoint;
        struct usb_host_interface *iface_desc;
        struct ds_device *dev;
-       int i, err;
+       int i, err, alt;
 
        dev = kmalloc(sizeof(struct ds_device), GFP_KERNEL);
        if (!dev) {
@@ -935,20 +936,25 @@ static int ds_probe(struct usb_interface *intf,
 
        usb_set_intfdata(intf, dev);
 
-       err = usb_set_interface(dev->udev, intf->altsetting[0].desc.bInterfaceNumber, 3);
+       err = usb_reset_configuration(dev->udev);
        if (err) {
-               printk(KERN_ERR "Failed to set alternative setting 3 for %d interface: err=%d.\n",
-                               intf->altsetting[0].desc.bInterfaceNumber, err);
+               dev_err(&dev->udev->dev,
+                       "Failed to reset configuration: err=%d.\n", err);
                goto err_out_clear;
        }
 
-       err = usb_reset_configuration(dev->udev);
+       /* alternative 3, 1ms interrupt (greatly speeds search), 64 byte bulk */
+       alt = 3;
+       err = usb_set_interface(dev->udev,
+               intf->altsetting[alt].desc.bInterfaceNumber, alt);
        if (err) {
-               printk(KERN_ERR "Failed to reset configuration: err=%d.\n", err);
+               dev_err(&dev->udev->dev, "Failed to set alternative setting %d "
+                       "for %d interface: err=%d.\n", alt,
+                       intf->altsetting[alt].desc.bInterfaceNumber, err);
                goto err_out_clear;
        }
 
-       iface_desc = &intf->altsetting[0];
+       iface_desc = &intf->altsetting[alt];
        if (iface_desc->desc.bNumEndpoints != NUM_EP-1) {
                printk(KERN_INFO "Num endpoints=%d. It is not DS9490R.\n", iface_desc->desc.bNumEndpoints);
                err = -EINVAL;