[PATCH] USBATM: xusbatm rewrite

The xusbatm driver is for otherwise unsupported modems.
All it does is grab hold of a user-specified set of
interfaces - the generic usbatm core methods (hopefully)
do the rest.  As Aurelio Arroyo discovered when he tried
to use xusbatm (big mistake!), the interface grabbing logic
was completely borked.  Here is a rewrite that works.

Signed-off-by:	Duncan Sands <baldrick@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 77 insertions, 37 deletions

diff --git a/drivers/usb/atm/xusbatm.c b/drivers/usb/atm/xusbatm.c
index ad5d3ff88dd9..83848ee2c6fe 100644
--- a/drivers/usb/atm/xusbatm.c
+++ b/drivers/usb/atm/xusbatm.c
@@ -41,6 +41,8 @@ XUSBATM_PARM(rx_endpoint, unsigned char, byte, "rx endpoint number");
 XUSBATM_PARM(tx_endpoint, unsigned char, byte, "tx endpoint number");
 XUSBATM_PARM(rx_padding, unsigned char, byte, "rx padding (default 0)");
 XUSBATM_PARM(tx_padding, unsigned char, byte, "tx padding (default 0)");
+XUSBATM_PARM(rx_altsetting, unsigned char, byte, "rx altsetting (default 0)");
+XUSBATM_PARM(tx_altsetting, unsigned char, byte, "rx altsetting (default 0)");
 
 static const char xusbatm_driver_name[] = "xusbatm";
 
@@ -48,61 +50,94 @@ static struct usbatm_driver xusbatm_drivers[XUSBATM_DRIVERS_MAX];
 static struct usb_device_id xusbatm_usb_ids[XUSBATM_DRIVERS_MAX + 1];
 static struct usb_driver xusbatm_usb_driver;
 
-static int usb_intf_has_ep(const struct usb_interface *intf, u8 ep)
+static struct usb_interface *xusbatm_find_intf (struct usb_device *usb_dev, int altsetting, u8 ep)
 {
+        struct usb_host_interface *alt;
+        struct usb_interface *intf;
         int i, j;
 
-        for (i = 0; i < intf->num_altsetting; i++) {
-                struct usb_host_interface *alt = intf->altsetting;
-                for (j = 0; j < alt->desc.bNumEndpoints; j++)
-                        if ((alt->endpoint[i].desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) == ep)
-                                return 1;
+        for(i = 0; i < usb_dev->actconfig->desc.bNumInterfaces; i++)
+                if ((intf = usb_dev->actconfig->interface[i]) && (alt = usb_altnum_to_altsetting(intf, altsetting)))
+                        for (j = 0; j < alt->desc.bNumEndpoints; j++)
+                                if (alt->endpoint[j].desc.bEndpointAddress == ep)
+                                        return intf;
+        return NULL;
+}
+
+static int xusbatm_capture_intf (struct usbatm_data *usbatm, struct usb_device *usb_dev,
+                struct usb_interface *intf, int altsetting, int claim)
+{
+        int ifnum = intf->altsetting->desc.bInterfaceNumber;
+        int ret;
+
+        if (claim && (ret = usb_driver_claim_interface(&xusbatm_usb_driver, intf, usbatm))) {
+                usb_err(usbatm, "%s: failed to claim interface %2d (%d)!\n", __func__, ifnum, ret);
+                return ret;
+        }
+        if ((ret = usb_set_interface(usb_dev, ifnum, altsetting))) {
+                usb_err(usbatm, "%s: altsetting %2d for interface %2d failed (%d)!\n", __func__, altsetting, ifnum, ret);
+                return ret;
         }
         return 0;
 }
 
+static void xusbatm_release_intf (struct usb_device *usb_dev, struct usb_interface *intf, int claimed)
+{
+        if (claimed) {
+                usb_set_intfdata(intf, NULL);
+                usb_driver_release_interface(&xusbatm_usb_driver, intf);
+        }
+}
+
 static int xusbatm_bind(struct usbatm_data *usbatm,
                         struct usb_interface *intf, const struct usb_device_id *id)
 {
         struct usb_device *usb_dev = interface_to_usbdev(intf);
         int drv_ix = id - xusbatm_usb_ids;
-        int rx_ep_present = usb_intf_has_ep(intf, rx_endpoint[drv_ix]);
-        int tx_ep_present = usb_intf_has_ep(intf, tx_endpoint[drv_ix]);
-        u8 searched_ep = rx_ep_present ? tx_endpoint[drv_ix] : rx_endpoint[drv_ix];
-        int i, ret;
+        int rx_alt = rx_altsetting[drv_ix];
+        int tx_alt = tx_altsetting[drv_ix];
+        struct usb_interface *rx_intf = xusbatm_find_intf(usb_dev, rx_alt, rx_endpoint[drv_ix]);
+        struct usb_interface *tx_intf = xusbatm_find_intf(usb_dev, tx_alt, tx_endpoint[drv_ix]);
+        int ret;
 
         usb_dbg(usbatm, "%s: binding driver %d: vendor %04x product %04x"
-                " rx: ep %02x padd %d tx: ep %02x padd %d\n",
+                " rx: ep %02x padd %d alt %2d tx: ep %02x padd %d alt %2d\n",
                 __func__, drv_ix, vendor[drv_ix], product[drv_ix],
-                rx_endpoint[drv_ix], rx_padding[drv_ix],
-                tx_endpoint[drv_ix], tx_padding[drv_ix]);
+                rx_endpoint[drv_ix], rx_padding[drv_ix], rx_alt,
+                tx_endpoint[drv_ix], tx_padding[drv_ix], tx_alt);
+
+        if (!rx_intf || !tx_intf) {
+                if (!rx_intf)
+                        usb_dbg(usbatm, "%s: no interface contains endpoint %02x in altsetting %2d\n",
+                                __func__, rx_endpoint[drv_ix], rx_alt);
+                if (!tx_intf)
+                        usb_dbg(usbatm, "%s: no interface contains endpoint %02x in altsetting %2d\n",
+                                __func__, tx_endpoint[drv_ix], tx_alt);
+                return -ENODEV;
+        }
 
-        if (!rx_ep_present && !tx_ep_present) {
-                usb_dbg(usbatm, "%s: intf #%d has neither rx (%#x) nor tx (%#x) endpoint\n",
-                        __func__, intf->altsetting->desc.bInterfaceNumber,
-                        rx_endpoint[drv_ix], tx_endpoint[drv_ix]);
+        if ((rx_intf != intf) && (tx_intf != intf))
                 return -ENODEV;
+
+        if ((rx_intf == tx_intf) && (rx_alt != tx_alt)) {
+                usb_err(usbatm, "%s: altsettings clash on interface %2d (%2d vs %2d)!\n", __func__,
+                                rx_intf->altsetting->desc.bInterfaceNumber, rx_alt, tx_alt);
+                return -EINVAL;
         }
 
-        if (rx_ep_present && tx_ep_present)
-                return 0;
+        usb_dbg(usbatm, "%s: rx If#=%2d; tx If#=%2d\n", __func__,
+                        rx_intf->altsetting->desc.bInterfaceNumber,
+                        tx_intf->altsetting->desc.bInterfaceNumber);
 
-        for(i = 0; i < usb_dev->actconfig->desc.bNumInterfaces; i++) {
-                struct usb_interface *cur_if = usb_dev->actconfig->interface[i];
-
-                if (cur_if != intf && usb_intf_has_ep(cur_if, searched_ep)) {
-                        ret = usb_driver_claim_interface(&xusbatm_usb_driver,
-                                                         cur_if, usbatm);
-                        if (!ret)
-                                usb_err(usbatm, "%s: failed to claim interface #%d (%d)\n",
-                                        __func__, cur_if->altsetting->desc.bInterfaceNumber, ret);
-                        return ret;
-                }
+        if ((ret = xusbatm_capture_intf(usbatm, usb_dev, rx_intf, rx_alt, rx_intf != intf)))
+                return ret;
+
+        if ((tx_intf != rx_intf) && (ret = xusbatm_capture_intf(usbatm, usb_dev, tx_intf, tx_alt, tx_intf != intf))) {
+                xusbatm_release_intf(usb_dev, rx_intf, rx_intf != intf);
+                return ret;
         }
 
-        usb_err(usbatm, "%s: no interface has endpoint %#x\n",
-                __func__, searched_ep);
-        return -ENODEV;
+        return 0;
 }
 
 static void xusbatm_unbind(struct usbatm_data *usbatm,
@@ -114,9 +149,12 @@ static void xusbatm_unbind(struct usbatm_data *usbatm,
         usb_dbg(usbatm, "%s entered\n", __func__);
 
         for(i = 0; i < usb_dev->actconfig->desc.bNumInterfaces; i++) {
-                struct usb_interface *cur_if = usb_dev->actconfig->interface[i];
-                usb_set_intfdata(cur_if, NULL);
-                usb_driver_release_interface(&xusbatm_usb_driver, cur_if);
+                struct usb_interface *cur_intf = usb_dev->actconfig->interface[i];
+
+                if (cur_intf && (usb_get_intfdata(cur_intf) == usbatm)) {
+                        usb_set_intfdata(cur_intf, NULL);
+                        usb_driver_release_interface(&xusbatm_usb_driver, cur_intf);
+                }
         }
 }
 
@@ -161,11 +199,13 @@ static int __init xusbatm_init(void)
         }
 
         for (i = 0; i < num_vendor; i++) {
+                rx_endpoint[i] |= USB_DIR_IN;
+                tx_endpoint[i] &= USB_ENDPOINT_NUMBER_MASK;
+
                 xusbatm_usb_ids[i].match_flags  = USB_DEVICE_ID_MATCH_DEVICE;
                 xusbatm_usb_ids[i].idVendor     = vendor[i];
                 xusbatm_usb_ids[i].idProduct    = product[i];
 
-
                 xusbatm_drivers[i].driver_name  = xusbatm_driver_name;
                 xusbatm_drivers[i].bind         = xusbatm_bind;
                 xusbatm_drivers[i].unbind       = xusbatm_unbind;