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authorFelipe Balbi <balbi@ti.com>2012-01-02 13:35:41 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2012-01-12 11:29:43 -0800
commitd2570fc048ca1307e64572c825e0d7908bd60a21 (patch)
tree46414bec9de8f5858729c6930f7d88fc9f6e786f
parent5b511b783385bc68663e4729be7f169ce3061e6d (diff)
downloadvexpress-lsk-d2570fc048ca1307e64572c825e0d7908bd60a21.tar.gz
usb: ch9: fix up MaxStreams helper
commit 18b7ede5f7ee2092aedcb578d3ac30bd5d4fc23c upstream. [ removed the dwc3 portion of the patch as it didn't apply to older kernels - gregkh] According to USB 3.0 Specification Table 9-22, if bmAttributes [4:0] are set to zero, it means "no streams supported", but the way this helper was defined on Linux, we will *always* have one stream which might cause several problems. For example on DWC3, we would tell the controller endpoint has streams enabled and yet start transfers with Stream ID set to 0, which would goof up the host side. While doing that, convert the macro to an inline function due to the different checks we now need. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/host/xhci.c3
-rw-r--r--include/linux/usb/ch9.h20
2 files changed, 20 insertions, 3 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 36f9dd81c49..b33f0598ccf 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2797,8 +2797,7 @@ static int xhci_calculate_streams_and_bitmask(struct xhci_hcd *xhci,
if (ret < 0)
return ret;
- max_streams = USB_SS_MAX_STREAMS(
- eps[i]->ss_ep_comp.bmAttributes);
+ max_streams = usb_ss_max_streams(&eps[i]->ss_ep_comp);
if (max_streams < (*num_streams - 1)) {
xhci_dbg(xhci, "Ep 0x%x only supports %u stream IDs.\n",
eps[i]->desc.bEndpointAddress,
diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index d5da6c68c25..61b29057b05 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -605,8 +605,26 @@ struct usb_ss_ep_comp_descriptor {
} __attribute__ ((packed));
#define USB_DT_SS_EP_COMP_SIZE 6
+
/* Bits 4:0 of bmAttributes if this is a bulk endpoint */
-#define USB_SS_MAX_STREAMS(p) (1 << ((p) & 0x1f))
+static inline int
+usb_ss_max_streams(const struct usb_ss_ep_comp_descriptor *comp)
+{
+ int max_streams;
+
+ if (!comp)
+ return 0;
+
+ max_streams = comp->bmAttributes & 0x1f;
+
+ if (!max_streams)
+ return 0;
+
+ max_streams = 1 << max_streams;
+
+ return max_streams;
+}
+
/* Bits 1:0 of bmAttributes if this is an isoc endpoint */
#define USB_SS_MULT(p) (1 + ((p) & 0x3))