Cleaning out my queue of most minor patches:
- Provides some kerneldoc for 'struct usb_interface' now that
the API is highlighting it.
- Fixes usb_set_interface() so it doesn't affect other interfaces.
This provides the right place for an eventual HCD call to clean
out now-invalid records of endpoint state, and also gets rid of
a potential SMP issue where drivers on different interfaces
calling concurrently could clobber each other. (Per-interface
data doesn't need locking except against config changes.)
- It's OK to pass URB_NO_INTERRUPT hints if you're queueing a
bunch of interrupt transfers.
The set_interface call should eventually take the interface as a
parameter, it's one of the few left using the "device plus magic
number" identifier. I have a partial patch for that, but it doesn't
handle the (newish) ALSA usb audio driver or a few other callers.
Please merge to Linus' latest.
- Dave
--- ./include/linux/usb.h-dist Sun Oct 13 04:27:46 2002
+++ ./include/linux/usb.h Sun Oct 13 05:42:23 2002
@@ -223,10 +223,40 @@
};
+/**
+ * struct usb_interface - what usb device drivers talk to
+ * @altsetting: array of interface descriptors, one for each alternate
+ * setting that may be selected. each one includes a set of
+ * endpoint configurations.
+ * @num_altsetting: number of altsettings defined.
+ * @act_altsetting: index of current altsetting. this number is always
+ * less than num_altsetting. after the device is configured, each
+ * interface uses its default setting of zero.
+ * @dev: driver model's view of this device
+ *
+ * USB device drivers attach to interfaces on a physical device. Each
+ * interface encapsulates a single high level function, such as feeding
+ * an audio stream to a speaker or reporting a change in a volume control.
+ * Many USB devices only have one interface. The protocol used to talk to
+ * an interface's endpoints can be defined in a usb "class" specification,
+ * or by a product's vendor. The (default) control endpoint is part of
+ * every interface, but is never listed among the interface's descriptors.
+ *
+ * The driver that is bound to the interface can use standard driver model
+ * calls such as dev_get_drvdata() on the dev member of this structure.
+ *
+ * Each interface may have alternate settings. The initial configuration
+ * of a device sets the first of these, but the device driver can change
+ * that setting using usb_set_interface(). Alternate settings are often
+ * used to control the the use of periodic endpoints, such as by having
+ * different endpoints use different amounts of reserved USB bandwidth.
+ * All standards-conformant USB devices that use isochronous endpoints
+ * will use them in non-default settings.
+ */
struct usb_interface {
struct usb_interface_descriptor *altsetting;
- int act_altsetting; /* active alternate setting */
- int num_altsetting; /* number of alternate settings */
- int max_altsetting; /* total memory allocated */
+ unsigned act_altsetting; /* active alternate setting */
+ unsigned num_altsetting; /* number of alternate settings */
+ unsigned max_altsetting; /* total memory allocated */
struct usb_driver *driver; /* driver */
--- ./drivers-dist/usb/core/urb.c Sun Oct 13 04:35:13 2002
+++ ./drivers/usb/core/urb.c Sun Oct 13 05:44:51 2002
@@ -273,7 +273,7 @@
allowed = USB_ASYNC_UNLINK; // affects later unlinks
allowed |= URB_NO_DMA_MAP;
+ allowed |= URB_NO_INTERRUPT;
switch (temp) {
case PIPE_BULK:
- allowed |= URB_NO_INTERRUPT;
if (is_out)
allowed |= USB_ZERO_PACKET;
--- ./drivers-dist/usb/core/message.c Sun Oct 13 04:35:13 2002
+++ ./drivers/usb/core/message.c Sun Oct 13 05:16:09 2002
@@ -757,4 +757,5 @@
* This is used to enable data transfers on interfaces that may not
* be enabled by default. Not all devices support such configurability.
+ * Only the driver bound to an interface may change its setting.
*
* Within any given configuration, each interface may have several
@@ -809,4 +810,20 @@
return ret;
+ /* FIXME drivers shouldn't need to replicate/bugfix the logic here
+ * when they implement async or easily-killable versions of this or
+ * other "should-be-internal" functions (like clear_halt).
+ * should hcd+usbcore postprocess control requests?
+ */
+
+ /* prevent submissions using previous endpoint settings */
+ iface_as = iface->altsetting + iface->act_altsetting;
+ for (i = 0; i < iface_as->bNumEndpoints; i++) {
+ u8 ep = iface_as->endpoint [i].bEndpointAddress;
+ int out = !(ep & USB_DIR_IN);
+
+ ep &= USB_ENDPOINT_NUMBER_MASK;
+ (out ? dev->epmaxpacketout : dev->epmaxpacketin ) [ep] = 0;
+ // FIXME want hcd hook here, "no such endpoint"
+ }
iface->act_altsetting = alternate;
@@ -820,4 +837,5 @@
* However, EP0 toggles are re-synced for every individual transfer
* during the SETUP stage - hence EP0 toggles are "don't care" here.
+ * (Likewise, EP0 never "halts" on well designed devices.)
*/
@@ -825,14 +843,12 @@
for (i = 0; i < iface_as->bNumEndpoints; i++) {
u8 ep = iface_as->endpoint[i].bEndpointAddress;
+ int out = !(ep & USB_DIR_IN);
- usb_settoggle(dev, ep&USB_ENDPOINT_NUMBER_MASK, usb_endpoint_out(ep),
0);
+ ep &= USB_ENDPOINT_NUMBER_MASK;
+ usb_settoggle (dev, ep, out, 0);
+ (out ? dev->epmaxpacketout : dev->epmaxpacketin) [ep]
+ = iface_as->endpoint [ep].wMaxPacketSize;
}
- /* usb_set_maxpacket() sets the maxpacket size for all EP in all
- * interfaces but it shouldn't do any harm here: we have changed
- * the AS for the requested interface only, hence for unaffected
- * interfaces it's just re-application of still-valid values.
- */
- usb_set_maxpacket(dev);
return 0;
}
