summaryrefslogtreecommitdiff
path: root/drivers/usb
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/host/ehci-hcd.c36
1 files changed, 19 insertions, 17 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 55f4436..0ffd6f1 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -1154,6 +1154,23 @@ create_int_queue(struct usb_device *dev, unsigned long pipe, int queuesize,
struct int_queue *result = NULL;
int i;
+ /*
+ * Interrupt transfers requiring several transactions are not supported
+ * because bInterval is ignored.
+ *
+ * Also, ehci_submit_async() relies on wMaxPacketSize being a power of 2
+ * <= PKT_ALIGN if several qTDs are required, while the USB
+ * specification does not constrain this for interrupt transfers. That
+ * means that ehci_submit_async() would support interrupt transfers
+ * requiring several transactions only as long as the transfer size does
+ * not require more than a single qTD.
+ */
+ if (elementsize > usb_maxpacket(dev, pipe)) {
+ printf("%s: xfers requiring several transactions are not supported.\n",
+ __func__);
+ return NULL;
+ }
+
debug("Enter create_int_queue\n");
if (usb_pipetype(pipe) != PIPE_INTERRUPT) {
debug("non-interrupt pipe (type=%lu)", usb_pipetype(pipe));
@@ -1375,24 +1392,9 @@ submit_int_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
debug("dev=%p, pipe=%lu, buffer=%p, length=%d, interval=%d",
dev, pipe, buffer, length, interval);
- /*
- * Interrupt transfers requiring several transactions are not supported
- * because bInterval is ignored.
- *
- * Also, ehci_submit_async() relies on wMaxPacketSize being a power of 2
- * <= PKT_ALIGN if several qTDs are required, while the USB
- * specification does not constrain this for interrupt transfers. That
- * means that ehci_submit_async() would support interrupt transfers
- * requiring several transactions only as long as the transfer size does
- * not require more than a single qTD.
- */
- if (length > usb_maxpacket(dev, pipe)) {
- printf("%s: Interrupt transfers requiring several "
- "transactions are not supported.\n", __func__);
- return -1;
- }
-
queue = create_int_queue(dev, pipe, 1, length, buffer);
+ if (!queue)
+ return -1;
timeout = get_timer(0) + USB_TIMEOUT_MS(pipe);
while ((backbuffer = poll_int_queue(dev, queue)) == NULL)