Merge tag 'fixes-for-v5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-linus

Felipe writes:

USB: fixes for v5.7-rc6

The main part here are the important fixes for the raw-gadget before it
becomes an ABI. We're adding support for stall/halt/wedge which is
actually pretty important in many situations. There's also a NULL
pointer deref fix.

Apart from raw-gadget, I've included some recent sparse fixes to a few
drivers.

Signed-off-by: Felipe Balbi <balbi@kernel.org>

* tag 'fixes-for-v5.7-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb:
  usb: cdns3: gadget: make a bunch of functions static
  usb: mtu3: constify struct debugfs_reg32
  usb: gadget: udc: atmel: Make some symbols static
  usb: raw-gadget: fix null-ptr-deref when reenabling endpoints
  usb: raw-gadget: documentation updates
  usb: raw-gadget: support stalling/halting/wedging endpoints
  usb: raw-gadget: fix gadget endpoint selection
  usb: raw-gadget: improve uapi headers comments

Author: gregkh

Documentation/usb/raw-gadget.rst

@@ -27,9 +27,8 @@ differences are:
 3. Raw Gadget provides a way to select a UDC device/driver to bind to,
    while GadgetFS currently binds to the first available UDC.
 
-4. Raw Gadget uses predictable endpoint names (handles) across different
-   UDCs (as long as UDCs have enough endpoints of each required transfer
-   type).
+4. Raw Gadget explicitly exposes information about endpoints addresses and
+   capabilities allowing a user to write UDC-agnostic gadgets.
 
 5. Raw Gadget has ioctl-based interface instead of a filesystem-based one.
 
@@ -50,12 +49,36 @@ The typical usage of Raw Gadget looks like:
    Raw Gadget and react to those depending on what kind of USB device
    needs to be emulated.
 
+Note, that some UDC drivers have fixed addresses assigned to endpoints, and
+therefore arbitrary endpoint addresses can't be used in the descriptors.
+Nevertheles, Raw Gadget provides a UDC-agnostic way to write USB gadgets.
+Once a USB_RAW_EVENT_CONNECT event is received via USB_RAW_IOCTL_EVENT_FETCH,
+the USB_RAW_IOCTL_EPS_INFO ioctl can be used to find out information about
+endpoints that the UDC driver has. Based on that information, the user must
+chose UDC endpoints that will be used for the gadget being emulated, and
+properly assign addresses in endpoint descriptors.
+
+You can find usage examples (along with a test suite) here:
+
+https://github.com/xairy/raw-gadget
+
+Internal details
+~~~~~~~~~~~~~~~~
+
+Currently every endpoint read/write ioctl submits a USB request and waits until
+its completion. This is the desired mode for coverage-guided fuzzing (as we'd
+like all USB request processing happen during the lifetime of a syscall),
+and must be kept in the implementation. (This might be slow for real world
+applications, thus the O_NONBLOCK improvement suggestion below.)
+
 Potential future improvements
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-- Implement ioctl's for setting/clearing halt status on endpoints.
-
-- Reporting more events (suspend, resume, etc.) through
-  USB_RAW_IOCTL_EVENT_FETCH.
+- Report more events (suspend, resume, etc.) through USB_RAW_IOCTL_EVENT_FETCH.
 
 - Support O_NONBLOCK I/O.
+
+- Support USB 3 features (accept SS endpoint companion descriptor when
+  enabling endpoints; allow providing stream_id for bulk transfers).
+
+- Support ISO transfer features (expose frame_number for completed requests).

drivers/usb/cdns3/gadget.c

@@ -82,7 +82,7 @@ static int cdns3_ep_run_stream_transfer(struct cdns3_endpoint *priv_ep,
  * @ptr: address of device controller register to be read and changed
  * @mask: bits requested to clar
  */
-void cdns3_clear_register_bit(void __iomem *ptr, u32 mask)
+static void cdns3_clear_register_bit(void __iomem *ptr, u32 mask)
 {
 	mask = readl(ptr) & ~mask;
 	writel(mask, ptr);
@@ -137,7 +137,7 @@ struct usb_request *cdns3_next_request(struct list_head *list)
  *
  * Returns buffer or NULL if no buffers in list
  */
-struct cdns3_aligned_buf *cdns3_next_align_buf(struct list_head *list)
+static struct cdns3_aligned_buf *cdns3_next_align_buf(struct list_head *list)
 {
 	return list_first_entry_or_null(list, struct cdns3_aligned_buf, list);
 }
@@ -148,7 +148,7 @@ struct cdns3_aligned_buf *cdns3_next_align_buf(struct list_head *list)
  *
  * Returns request or NULL if no requests in list
  */
-struct cdns3_request *cdns3_next_priv_request(struct list_head *list)
+static struct cdns3_request *cdns3_next_priv_request(struct list_head *list)
 {
 	return list_first_entry_or_null(list, struct cdns3_request, list);
 }
@@ -190,7 +190,7 @@ dma_addr_t cdns3_trb_virt_to_dma(struct cdns3_endpoint *priv_ep,
 	return priv_ep->trb_pool_dma + offset;
 }
 
-int cdns3_ring_size(struct cdns3_endpoint *priv_ep)
+static int cdns3_ring_size(struct cdns3_endpoint *priv_ep)
 {
 	switch (priv_ep->type) {
 	case USB_ENDPOINT_XFER_ISOC:
@@ -345,7 +345,7 @@ static void cdns3_ep_inc_deq(struct cdns3_endpoint *priv_ep)
 	cdns3_ep_inc_trb(&priv_ep->dequeue, &priv_ep->ccs, priv_ep->num_trbs);
 }
 
-void cdns3_move_deq_to_next_trb(struct cdns3_request *priv_req)
+static void cdns3_move_deq_to_next_trb(struct cdns3_request *priv_req)
 {
 	struct cdns3_endpoint *priv_ep = priv_req->priv_ep;
 	int current_trb = priv_req->start_trb;
@@ -511,7 +511,7 @@ static void cdns3_wa2_descmiss_copy_data(struct cdns3_endpoint *priv_ep,
 	}
 }
 
-struct usb_request *cdns3_wa2_gadget_giveback(struct cdns3_device *priv_dev,
+static struct usb_request *cdns3_wa2_gadget_giveback(struct cdns3_device *priv_dev,
 					      struct cdns3_endpoint *priv_ep,
 					      struct cdns3_request *priv_req)
 {
@@ -551,7 +551,7 @@ struct usb_request *cdns3_wa2_gadget_giveback(struct cdns3_device *priv_dev,
 	return &priv_req->request;
 }
 
-int cdns3_wa2_gadget_ep_queue(struct cdns3_device *priv_dev,
+static int cdns3_wa2_gadget_ep_queue(struct cdns3_device *priv_dev,
 			      struct cdns3_endpoint *priv_ep,
 			      struct cdns3_request *priv_req)
 {
@@ -836,7 +836,7 @@ void cdns3_gadget_giveback(struct cdns3_endpoint *priv_ep,
 		cdns3_gadget_ep_free_request(&priv_ep->endpoint, request);
 }
 
-void cdns3_wa1_restore_cycle_bit(struct cdns3_endpoint *priv_ep)
+static void cdns3_wa1_restore_cycle_bit(struct cdns3_endpoint *priv_ep)
 {
 	/* Work around for stale data address in TRB*/
 	if (priv_ep->wa1_set) {
@@ -1904,7 +1904,7 @@ static int cdns3_ep_onchip_buffer_reserve(struct cdns3_device *priv_dev,
 	return 0;
 }
 
-void cdns3_stream_ep_reconfig(struct cdns3_device *priv_dev,
+static void cdns3_stream_ep_reconfig(struct cdns3_device *priv_dev,
 			      struct cdns3_endpoint *priv_ep)
 {
 	if (!priv_ep->use_streams || priv_dev->gadget.speed < USB_SPEED_SUPER)
@@ -1925,7 +1925,7 @@ void cdns3_stream_ep_reconfig(struct cdns3_device *priv_dev,
 			       EP_CFG_TDL_CHK | EP_CFG_SID_CHK);
 }
 
-void cdns3_configure_dmult(struct cdns3_device *priv_dev,
+static void cdns3_configure_dmult(struct cdns3_device *priv_dev,
 			   struct cdns3_endpoint *priv_ep)
 {
 	struct cdns3_usb_regs __iomem *regs = priv_dev->regs;