Hi,

Krzysztof Opasiak [off-list ref] writes:

On 01/31/2017 02:08 PM, Felipe Balbi wrote:

quoted

If we're dealing with SuperSpeed endpoints, we need
to make sure to pass along the companion descriptor
and initialize fields needed by the Gadget
API. Eventually, f_fs.c should be converted to use
config_ep_by_speed() like all other functions,
though.

Cc: <redacted>
Signed-off-by: Felipe Balbi <redacted>
---

Will be sent in a pull request during v4.11-rc

 drivers/usb/gadget/function/f_fs.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/f_fs.c b/drivers/usb/gadget/function/f_fs.c
index 87fccf611b69..86aba2ebb3ef 100644
--- a/drivers/usb/gadget/function/f_fs.c
+++ b/drivers/usb/gadget/function/f_fs.c

@@ -1833,11 +1833,14 @@ static int ffs_func_eps_enable(struct ffs_function *func)
 	spin_lock_irqsave(&func->ffs->eps_lock, flags);
 	while(count--) {
 		struct usb_endpoint_descriptor *ds;
+		struct usb_ss_ep_comp_descriptor *comp_desc = NULL;
+		int needs_comp_desc = false;
 		int desc_idx;
 
-		if (ffs->gadget->speed == USB_SPEED_SUPER)
+		if (ffs->gadget->speed == USB_SPEED_SUPER) {
 			desc_idx = 2;
-		else if (ffs->gadget->speed == USB_SPEED_HIGH)
+			needs_comp_desc = true;
+		} else if (ffs->gadget->speed == USB_SPEED_HIGH)
 			desc_idx = 1;
 		else
 			desc_idx = 0;

@@ -1854,6 +1857,14 @@ static int ffs_func_eps_enable(struct ffs_function *func)
 
 		ep->ep->driver_data = ep;
 		ep->ep->desc = ds;
+
+		comp_desc = (struct usb_ss_ep_comp_descriptor *)(ds +
+				USB_DT_ENDPOINT_SIZE);
+		ep->ep->maxburst = comp_desc->bMaxBurst + 1;
+
+		if (needs_comp_desc)
+			ep->ep->comp_desc = comp_desc;
+

Please correct me if I'm wrong but wouldn't we read rubbish here if user
provided us SS ep descriptor without companion descriptor?

companion desc is required for SS endpoints, it's also required that
they follow EP desc. If user doesn't write it, don't they deserve the
errors they'll have?

-- 
balbi