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.
Cc: stable@xxxxxxxxxxxxxxx
Cc: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
this should be applied as far back as 2.6.35 (when the
commit was first introduced), but of course the DWC3 part
will only apply to 3.2-stable. You can safely ignore the
DWC3 part for anything older than 3.2-stable and, hopefully,
the patch should still apply.
Changes from v2:
- Fix typo on commit log (s/enable/enabled)
drivers/usb/dwc3/gadget.c | 3 +--
drivers/usb/host/xhci.c | 3 +--
include/linux/usb/ch9.h | 20 +++++++++++++++++++-
3 files changed, 21 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 12975ac..76036d0 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -234,8 +234,7 @@ static int dwc3_gadget_set_ep_config(struct dwc3 *dwc, struct dwc3_ep *dep,
params.param1 = DWC3_DEPCFG_XFER_COMPLETE_EN
| DWC3_DEPCFG_XFER_NOT_READY_EN;
- if (comp_desc && USB_SS_MAX_STREAMS(comp_desc->bmAttributes)
- && usb_endpoint_xfer_bulk(desc)) {
+ if (usb_ss_max_streams(comp_desc) && usb_endpoint_xfer_bulk(desc)) {
params.param1 |= DWC3_DEPCFG_STREAM_CAPABLE
| DWC3_DEPCFG_STREAM_EVENT_EN;
dep->stream_capable = true;
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index a1afb7c..b0d9ac6 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2796,8 +2796,7 @@ 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 d5da6c6..61b2905 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))
--
1.7.8.2
--
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