[PATCH] USBATM: measure buffer size in bytes; force valid sizes

Change the module parameters rcv_buf_size and snd_buf_size to
specify buffer sizes in bytes rather than ATM cells.  Since
there is some danger that users may not notice this change,
the parameters are renamed to rcv_buf_bytes etc.  The transmit
buffer needs to be a multiple of the ATM cell size in length,
while the receive buffer should be a multiple of the endpoint
maxpacket size (this wasn't enforced before, which causes trouble
with isochronous transfers), so enforce these restrictions.  Now
that the usbatm probe method inspects the endpoint maxpacket size,
minidriver bind routines need to set the correct alternate setting
for the interface in their bind routine.  This is the reason for
the speedtch changes.

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

1 files changed, 25 insertions, 5 deletions

diff --git a/drivers/usb/atm/speedtch.c b/drivers/usb/atm/speedtch.c
index 43ec758..0e98167 100644
--- a/drivers/usb/atm/speedtch.c
+++ b/drivers/usb/atm/speedtch.c
@@ -89,6 +89,7 @@ MODULE_PARM_DESC(sw_buffering,
 		 "Enable software buffering (default: "
 		 __MODULE_STRING(DEFAULT_SW_BUFFERING) ")");
 
+#define INTERFACE_DATA		1
 #define ENDPOINT_INT		0x81
 #define ENDPOINT_DATA		0x07
 #define ENDPOINT_FIRMWARE	0x05
@@ -98,6 +99,8 @@ MODULE_PARM_DESC(sw_buffering,
 struct speedtch_instance_data {
 	struct usbatm_data *usbatm;
 
+	unsigned int altsetting;
+
 	struct work_struct status_checker;
 
 	unsigned char last_status;
@@ -270,6 +273,11 @@ static int speedtch_upload_firmware(struct speedtch_instance_data *instance,
 	   because we're in our own kernel thread anyway. */
 	msleep_interruptible(1000);
 
+	if ((ret = usb_set_interface(usb_dev, INTERFACE_DATA, instance->altsetting)) < 0) {
+		usb_err(usbatm, "%s: setting interface to %d failed (%d)!\n", __func__, instance->altsetting, ret);
+		goto out_free;
+	}
+
 	/* Enable software buffering, if requested */
 	if (sw_buffering)
 		speedtch_set_swbuff(instance, 1);
@@ -586,11 +594,6 @@ static int speedtch_atm_start(struct usbatm_data *usbatm, struct atm_dev *atm_de
 
 	atm_dbg(usbatm, "%s entered\n", __func__);
 
-	if ((ret = usb_set_interface(usb_dev, 1, altsetting)) < 0) {
-		atm_dbg(usbatm, "%s: usb_set_interface returned %d!\n", __func__, ret);
-		return ret;
-	}
-
 	/* Set MAC address, it is stored in the serial number */
 	memset(atm_dev->esi, 0, sizeof(atm_dev->esi));
 	if (usb_string(usb_dev, usb_dev->descriptor.iSerialNumber, mac_str, sizeof(mac_str)) == 12) {
@@ -725,6 +728,23 @@ static int speedtch_bind(struct usbatm_data *usbatm,
 
 	instance->usbatm = usbatm;
 
+	/* altsetting may change at any moment, so take a snapshot */
+	instance->altsetting = altsetting;
+
+	if (instance->altsetting)
+		if ((ret = usb_set_interface(usb_dev, INTERFACE_DATA, instance->altsetting)) < 0) {
+			usb_err(usbatm, "%s: setting interface to %2d failed (%d)!\n", __func__, instance->altsetting, ret);
+			instance->altsetting = 0; /* fall back to default */
+		}
+
+	if (!instance->altsetting) {
+		if ((ret = usb_set_interface(usb_dev, INTERFACE_DATA, DEFAULT_ALTSETTING)) < 0) {
+			usb_err(usbatm, "%s: setting interface to %2d failed (%d)!\n", __func__, DEFAULT_ALTSETTING, ret);
+			goto fail_free;
+		}
+		instance->altsetting = DEFAULT_ALTSETTING;
+	}
+
 	INIT_WORK(&instance->status_checker, (void *)speedtch_check_status, instance);
 
 	instance->status_checker.timer.function = speedtch_status_poll;