[PATCH 11/14] w1: ds2490 USB setup fixes

David Fries
2013-12-29T06:53:51Z

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>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
---
drivers/w1/masters/ds2490.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c
index 6a3d0a1..cd59e12 100644
--- a/drivers/w1/masters/ds2490.c
+++ b/drivers/w1/masters/ds2490.c
@@ -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;
--
1.7.10.4