Commit d0b4652f authored Jan 30, 2013 by Alan Stern Committed by Greg Kroah-Hartman Jan 31, 2013

USB: altsetting overrides for usbtest



The usbtest driver includes some rather simple-minded logic for
selecting an altsetting to test.  It doesn't work well for the g_zero
gadget, because it selects altsetting 0 (which doesn't have
isochronous endpoints) rather than altsetting 1 (which does have them,
if the gadget's hardware supports them).  This prevents usbtest's
isochronous tests (15, 16, 22, and 23) from working with g_zero.

Since g_zero is one of the most common gadget drivers used for USB
testing, usbtest should do a better job of supporting it.  But since
some programs may rely on the current scheme for selecting
altsettings, I didn't want to change it.

Instead, this patch (as1655) adds a module parameter to usbtest, which
can be used to override the default altsetting.  Since usbtest is
never used by normal users (most distributions probably don't even
build it), the new module parameter won't inconvenience anybody.  In
any case, it is entirely optional -- leaving it unset preserves the
existing behavior.

The patch also fixes a related bug in usbtest: After selecting an
altsetting, the driver neglects to store its selection.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 7b8bc3aa

drivers/usb/misc/usbtest.c

+12 −1

Original line number	Diff line number	Diff line
		@@ -11,6 +11,12 @@
		#include <linux/usb.h>


		/-------------------------------------------------------------------------/

		static int override_alt = -1;
		module_param_named(alt, override_alt, int, 0644);
		MODULE_PARM_DESC(alt, ">= 0 to override altsetting selection");

		/-------------------------------------------------------------------------/

		/* FIXME make these public somewhere; usbdevfs.h? */
		@@ -103,6 +109,10 @@ get_endpoints(struct usbtest_dev dev, struct usb_interface intf)
		iso_in = iso_out = NULL;
		alt = intf->altsetting + tmp;

		if (override_alt >= 0 &&
		override_alt != alt->desc.bAlternateSetting)
		continue;

		/* take the first altsetting with in-bulk + out-bulk;
		* ignore other endpoints and altsettings.
		*/
		@@ -144,6 +154,7 @@ try_iso:

		found:
		udev = testdev_to_usbdev(dev);
		dev->info->alt = alt->desc.bAlternateSetting;
		if (alt->desc.bAlternateSetting != 0) {
		tmp = usb_set_interface(udev,
		alt->desc.bInterfaceNumber,
		@@ -2280,7 +2291,7 @@ usbtest_probe(struct usb_interface intf, const struct usb_device_id id)
		wtest = " intr-out";
		}
		} else {
		if (info->autoconf) {
		if (override_alt >= 0 \|\| info->autoconf) {
		int status;

		status = get_endpoints(dev, intf);

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