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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 11:35:33 -0800
commit9f3657ac7841b871c5d2dc8ab51fb08080ae67b1 (patch)
tree0c4ec4d85a036dd1e61a6867c76dc49f8e519891
parent9f1efce9d1265de3888ddb4a91cb6d5b14536ff2 (diff)
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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 b880e546d88..107438eca2b 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2184,8 +2184,7 @@ 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 0fd3fbdd828..cf65b5cff72 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -583,8 +583,26 @@ 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))