1 files changed, 15 insertions, 1 deletions

diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index 2e49de820b14..c0e752cffc68 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -657,6 +657,14 @@ qh_make (
         type = usb_pipetype (urb->pipe);
         maxp = usb_maxpacket (urb->dev, urb->pipe, !is_input);
 
+        /* 1024 byte maxpacket is a hardware ceiling.  High bandwidth
+         * acts like up to 3KB, but is built from smaller packets.
+         */
+        if (max_packet(maxp) > 1024) {
+                ehci_dbg(ehci, "bogus qh maxpacket %d\n", max_packet(maxp));
+                goto done;
+        }
+
         /* Compute interrupt scheduling parameters just once, and save.
          * - allowing for high bandwidth, how many nsec/uframe are used?
          * - split transactions need a second CSPLIT uframe; same question
@@ -757,7 +765,13 @@ qh_make (
                         info2 |= (EHCI_TUNE_MULT_HS << 30);
                 } else if (type == PIPE_BULK) {
                         info1 |= (EHCI_TUNE_RL_HS << 28);
-                        info1 |= 512 << 16;     /* usb2 fixed maxpacket */
+                        /* The USB spec says that high speed bulk endpoints
+                         * always use 512 byte maxpacket.  But some device
+                         * vendors decided to ignore that, and MSFT is happy
+                         * to help them do so.  So now people expect to use
+                         * such nonconformant devices with Linux too; sigh.
+                         */
+                        info1 |= max_packet(maxp) << 16;
                         info2 |= (EHCI_TUNE_MULT_HS << 30);
                 } else {                /* PIPE_INTERRUPT */
                         info1 |= max_packet (maxp) << 16;