USB 3.1 devices can return a new SuperSpeedPlus isoc endpoint companion
descriptor for a isochronous endpoint that requires more than 48K bytes
per Service Interval.
The new descriptor immediately follows the old USB 3.0 SuperSpeed Endpoint
Companion and will provide a new BytesPerInterval value.
It is parsed and stored in struct usb_host_endpoint with the other endpoint
related descriptors, and should be used by USB3.1 capable hosts to reserve
bus time in the schedule.
Signed-off-by: Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx>
---
drivers/usb/core/config.c | 31 +++++++++++++++++++++++++++++++
include/linux/usb.h | 2 ++
2 files changed, 33 insertions(+)
diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
index bbcf400..58d0898 100644
--- a/drivers/usb/core/config.c
+++ b/drivers/usb/core/config.c
@@ -43,6 +43,27 @@ static int find_next_descriptor(unsigned char *buffer, int size,
return buffer - buffer0;
}
+static void usb_parse_ssp_isoc_endpoint_companion(struct device *ddev,
+ int cfgno, int inum, int asnum, struct usb_host_endpoint *ep,
+ unsigned char *buffer, int size)
+{
+ struct usb_ssp_isoc_ep_comp_descriptor *desc;
+
+ /*
+ * The SuperSpeedPlus Isoc endpoint companion descriptor immediately
+ * follows the SuperSpeed Endpoint Companion descriptor
+ */
+ desc = (struct usb_ssp_isoc_ep_comp_descriptor *) buffer;
+ if (desc->bDescriptorType != USB_DT_SSP_ISOC_ENDPOINT_COMP ||
+ size < USB_DT_SSP_ISOC_EP_COMP_SIZE) {
+ dev_warn(ddev, "Invalid SuperSpeedPlus isoc endpoint companion"
+ "for config %d interface %d altsetting %d ep %d.\n",
+ cfgno, inum, asnum, ep->desc.bEndpointAddress);
+ return;
+ }
+ memcpy(&ep->ssp_isoc_ep_comp, desc, USB_DT_SSP_ISOC_EP_COMP_SIZE);
+}
+
static void usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno,
int inum, int asnum, struct usb_host_endpoint *ep,
unsigned char *buffer, int size)
@@ -54,6 +75,9 @@ static void usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno,
* be the first thing immediately following the endpoint descriptor.
*/
desc = (struct usb_ss_ep_comp_descriptor *) buffer;
+ buffer += desc->bLength;
+ size -= desc->bLength;
+
if (desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP ||
size < USB_DT_SS_EP_COMP_SIZE) {
dev_warn(ddev, "No SuperSpeed endpoint companion for config %d "
@@ -112,6 +136,7 @@ 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) &&
+ !USB_SS_SSP_ISOC_COMP(desc->bmAttributes) &&
USB_SS_MULT(desc->bmAttributes) > 3) {
dev_warn(ddev, "Isoc endpoint has Mult of %d in "
"config %d interface %d altsetting %d ep %d: "
@@ -121,6 +146,12 @@ static void usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno,
ep->ss_ep_comp.bmAttributes = 2;
}
+ /* Parse a possible SuperSpeedPlus isoc ep companion descriptor */
+ if (usb_endpoint_xfer_isoc(&ep->desc) &&
+ USB_SS_SSP_ISOC_COMP(desc->bmAttributes))
+ usb_parse_ssp_isoc_endpoint_companion(ddev, cfgno, inum, asnum,
+ ep, buffer, size);
+
if (usb_endpoint_xfer_isoc(&ep->desc))
max_tx = (desc->bMaxBurst + 1) *
(USB_SS_MULT(desc->bmAttributes)) *
diff --git a/include/linux/usb.h b/include/linux/usb.h
index dc0ea0d..8fc881a 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -50,6 +50,7 @@ struct ep_device;
* struct usb_host_endpoint - host-side endpoint descriptor and queue
* @desc: descriptor for this endpoint, wMaxPacketSize in native byteorder
* @ss_ep_comp: SuperSpeed companion descriptor for this endpoint
+ * @ssp_isoc_ep_comp: SuperSpeedPlus isoc companion descriptor for this endpoint
* @urb_list: urbs queued to this endpoint; maintained by usbcore
* @hcpriv: for use by HCD; typically holds hardware dma queue head (QH)
* with one or more transfer descriptors (TDs) per urb
@@ -65,6 +66,7 @@ struct ep_device;
struct usb_host_endpoint {
struct usb_endpoint_descriptor desc;
struct usb_ss_ep_comp_descriptor ss_ep_comp;
+ struct usb_ssp_isoc_ep_comp_descriptor ssp_isoc_ep_comp;
struct list_head urb_list;
void *hcpriv;
struct ep_device *ep_dev; /* For sysfs info */
--
1.9.1
--
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