[PATCH 3.4 56/92] usb: Use the USB_SS_MULT() macro to get the burst multiplier.

lizf
2016-04-18T10:50:10Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

3.4.112-rc1 review patch. If anyone has any objections, please let me know.

------------------

commit ff30cbc8da425754e8ab96904db1d295bd034f27 upstream.

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.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zefan Li <lizefan@huawei.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 cc1004a..6baa836 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -114,7 +114,7 @@ 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,
@@ -123,7 +123,8 @@ 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