Bits 1:0 of the bmAttributes are used for the burst multiplier.
The rest of the bits used to be reserved (zero), but USB3.1 takes bit 7
into use.

Use the existing USB_SS_MULT() macro instead to make sure the mult value
and hence max packet calculations are correct for USB3.1 devices.

Note that burst multiplier in bmAttributes is zero based and that
the USB_SS_MULT() macro adds one.

Cc: <sta...@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.ny...@linux.intel.com>
---
 drivers/usb/core/config.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index b2a540b..b9ddf0c 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -112,7 +112,7 @@ static void usb_parse_ss_endpoint_companion(struct device 
*ddev, int cfgno,
                                cfgno, inum, asnum, ep->desc.bEndpointAddress);
                ep->ss_ep_comp.bmAttributes = 16;
        } else if (usb_endpoint_xfer_isoc(&ep->desc) &&
-                       desc->bmAttributes > 2) {
+                  USB_SS_MULT(desc->bmAttributes) > 3) {
                dev_warn(ddev, "Isoc endpoint has Mult of %d in "
                                "config %d interface %d altsetting %d ep %d: "
                                "setting to 3\n", desc->bmAttributes + 1,
@@ -121,7 +121,8 @@ static void usb_parse_ss_endpoint_companion(struct device 
*ddev, int cfgno,
        }
 
        if (usb_endpoint_xfer_isoc(&ep->desc))
-               max_tx = (desc->bMaxBurst + 1) * (desc->bmAttributes + 1) *
+               max_tx = (desc->bMaxBurst + 1) *
+                       (USB_SS_MULT(desc->bmAttributes)) *
                        usb_endpoint_maxp(&ep->desc);
        else if (usb_endpoint_xfer_int(&ep->desc))
                max_tx = usb_endpoint_maxp(&ep->desc) *
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to