Commit 18b7ede5 authored by Felipe Balbi's avatar Felipe Balbi Committed by Greg Kroah-Hartman
Browse files

usb: ch9: fix up MaxStreams helper 



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: default avatarFelipe Balbi <balbi@ti.com>
Signed-off-by: default avatarSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent e28dbb06

drivers/usb/dwc3/gadget.c

+1 −2
Original line number Diff line number Diff line
@@ -297,8 +297,7 @@ 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;

drivers/usb/host/xhci.c

+1 −2
Original line number Diff line number Diff line
@@ -2799,8 +2799,7 @@ 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,

include/linux/usb/ch9.h

+19 −1
Original line number Diff line number Diff line
@@ -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))

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