[02/15] usb: core: urb: Check SSP isoc ep comp descriptor

* [02/15] usb: core: urb: Check SSP isoc ep comp descriptor
@ 2018-01-05 20:13 Thinh Nguyen
  0 siblings, 0 replies; only message in thread
From: Thinh Nguyen @ 2018-01-05 20:13 UTC (permalink / raw)
  To: Thinh Nguyen, linux-usb, Vamsi Krishna Samavedam,
	Gustavo A. R. Silva, Takashi Iwai
  Cc: John Youn

The maximum bytes per interval for USB SuperSpeed Plus can be set by
isoc endpoint companion descriptor when it is above 48K. If the
descriptor is provided, then use its value.

USB 3.1 spec 9.6.8

Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
---
 drivers/usb/core/urb.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index 9fdf137c4865..0ab4b896e3f3 100644
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -433,6 +433,14 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
 			max *= mult;
 		}
 
+		if (dev->speed == USB_SPEED_SUPER_PLUS &&
+		    USB_SS_SSP_ISOC_COMP(ep->ss_ep_comp.bmAttributes)) {
+			struct usb_ssp_isoc_ep_comp_descriptor *isoc_ep_comp;
+
+			isoc_ep_comp = &ep->ssp_isoc_ep_comp;
+			max = le32_to_cpu(isoc_ep_comp->dwBytesPerInterval);
+		}
+
 		/* "high bandwidth" mode, 1-3 packets/uframe? */
 		if (dev->speed == USB_SPEED_HIGH)
 			max *= usb_endpoint_maxp_mult(&ep->desc);

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