linux-kernel - [PATCH 11/15] w1: ds2490 USB setup fixes

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Message-Id: <1389846566-28862-12-git-send-email-David@Fries.net>
Date:	Wed, 15 Jan 2014 22:29:22 -0600
From:	David Fries <David@...es.net>
To:	linux-kernel@...r.kernel.org
Cc:	Evgeniy Polyakov <zbr@...emap.net>, GregKH <greg@...ah.com>
Subject: [PATCH 11/15] w1: ds2490 USB setup fixes

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@...es.net>
Acked-by: Evgeniy Polyakov <zbr@...emap.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

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