usb: dwc2: host: Fix wMaxPacketSize handling (fix webcam regression)

In commit abb621844f6a ("usb: ch9: make usb_endpoint_maxp() return
only packet size") the API to usb_endpoint_maxp() changed.  It used to
just return wMaxPacketSize but after that commit it returned
wMaxPacketSize with the high bits (the multiplier) masked off.  If you
wanted to get the multiplier it was now up to your code to call the
new usb_endpoint_maxp_mult() which was introduced in
commit 541b6fe63023 ("usb: add helper to extract bits 12:11 of
wMaxPacketSize").

Prior to the API change most host drivers were updated, but no update
was made to dwc2.  Presumably it was assumed that dwc2 was too
simplistic to use the multiplier and thus just didn't support a
certain class of USB devices.  However, it turns out that dwc2 did use
the multiplier and many devices using it were working quite nicely.
That means that many USB devices have been broken since the API
change.  One such device is a Logitech HD Pro Webcam C920.

Specifically, though dwc2 didn't directly call usb_endpoint_maxp(), it
did call usb_maxpacket() which in turn called usb_endpoint_maxp().

Let's update dwc2 to work properly with the new API.

Fixes: abb621844f6a ("usb: ch9: make usb_endpoint_maxp() return only packet size")
Cc: stable@vger.kernel.org
Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 11 insertions, 9 deletions

diff --git a/drivers/usb/dwc2/hcd.h b/drivers/usb/dwc2/hcd.h
index c089ffa1f0a8..ce6445a06588 100644
--- a/drivers/usb/dwc2/hcd.h
+++ b/drivers/usb/dwc2/hcd.h
@@ -171,7 +171,8 @@ struct dwc2_hcd_pipe_info {
 	u8 ep_num;
 	u8 pipe_type;
 	u8 pipe_dir;
-	u16 mps;
+	u16 maxp;
+	u16 maxp_mult;
 };
 
 struct dwc2_hcd_iso_packet_desc {
@@ -264,6 +265,7 @@ struct dwc2_hs_transfer_time {
  *                       - USB_ENDPOINT_XFER_ISOC
  * @ep_is_in:           Endpoint direction
  * @maxp:               Value from wMaxPacketSize field of Endpoint Descriptor
+ * @maxp_mult:          Multiplier for maxp
  * @dev_speed:          Device speed. One of the following values:
  *                       - USB_SPEED_LOW
  *                       - USB_SPEED_FULL
@@ -340,6 +342,7 @@ struct dwc2_qh {
 	u8 ep_type;
 	u8 ep_is_in;
 	u16 maxp;
+	u16 maxp_mult;
 	u8 dev_speed;
 	u8 data_toggle;
 	u8 ping_state;
@@ -503,9 +506,14 @@ static inline u8 dwc2_hcd_get_pipe_type(struct dwc2_hcd_pipe_info *pipe)
 	return pipe->pipe_type;
 }
 
-static inline u16 dwc2_hcd_get_mps(struct dwc2_hcd_pipe_info *pipe)
+static inline u16 dwc2_hcd_get_maxp(struct dwc2_hcd_pipe_info *pipe)
+{
+	return pipe->maxp;
+}
+
+static inline u16 dwc2_hcd_get_maxp_mult(struct dwc2_hcd_pipe_info *pipe)
 {
-	return pipe->mps;
+	return pipe->maxp_mult;
 }
 
 static inline u8 dwc2_hcd_get_dev_addr(struct dwc2_hcd_pipe_info *pipe)
@@ -620,12 +628,6 @@ static inline bool dbg_urb(struct urb *urb)
 static inline bool dbg_perio(void) { return false; }
 #endif
 
-/* High bandwidth multiplier as encoded in highspeed endpoint descriptors */
-#define dwc2_hb_mult(wmaxpacketsize) (1 + (((wmaxpacketsize) >> 11) & 0x03))
-
-/* Packet size for any kind of endpoint descriptor */
-#define dwc2_max_packet(wmaxpacketsize) ((wmaxpacketsize) & 0x07ff)
-
 /*
  * Returns true if frame1 index is greater than frame2 index. The comparison
  * is done modulo FRLISTEN_64_SIZE. This accounts for the rollover of the