Solaris backend is not correctly setting the one transfer mode for Interrupt-In pipe

In sunos_check_device_and_status_open() function, if the target is an Interrupt-In
pipe, it opens the status endpoint first and writes USB_EP_INTR_ONE_XFER control
to the status endpoint to enable the one transfer mode. And it then closes the
status endpoint. After that, it opens the xfer endpoint and re-opens the status
endpoint. This is not correct, because closing the status endpoint is implicitly
disables the one tranfer mode.  As a result, an event notification won't be
delivered to the client in timely manner.  According to the comment in the source,
closing the status endpoint first and opening the xfer endpoint and status endpoint
in this order is intentional to avoit an issue that may happen if the USB device
has multiple configurations, which may be due to a ugen driver issue. To address
both issues, it can open the xfer endpoint first and immediately close it, which
will take care of the switch of configurations, if necessary.  Then, it can open
the status endpoint, enable the one transfer mode, and re-open the xfer endpoint.
This is a fix of libusb#620.

Closes #629

Signed-off-by: Nathan Hjelm <hjelmn@google.com>

diff --git a/libusb/os/sunos_usb.c b/libusb/os/sunos_usb.c
index 6a3f633..c9a16fa 100644 (file)
--- a/libusb/os/sunos_usb.c
+++ b/libusb/os/sunos_usb.c
@@ -901,18 +901,50 @@ sunos_check_device_and_status_open(struct libusb_device_handle *hdl,
        (void) snprintf(statfilename, PATH_MAX, "%sstat", filename);
 
        /*
-        * for interrupt IN endpoints, we need to enable one xfer
-        * mode before opening the endpoint
+        * In case configuration has been switched, the xfer endpoint needs
+        * to be opened before the status endpoint, due to a ugen issue.
+        * However, to enable the one transfer mode for an Interrupt-In pipe,
+        * the status endpoint needs to be opened before the xfer endpoint.
+        * So, open the xfer mode first and close it immediately
+        * as a workaround. This will handle the configuration switch.
+        * Then, open the status endpoint.  If for an Interrupt-in pipe,
+        * write the USB_EP_INTR_ONE_XFER control to the status endpoint
+        * to enable the one transfer mode.  Then, re-open the xfer mode.
+        */
+       if (ep_type == LIBUSB_TRANSFER_TYPE_ISOCHRONOUS) {
+               mode = O_RDWR;
+       } else if (ep_addr & LIBUSB_ENDPOINT_IN) {
+               mode = O_RDONLY;
+       } else {
+               mode = O_WRONLY;
+       }
+       /* Open the xfer endpoint first */
+       if ((fd = open(filename, mode)) == -1) {
+               usbi_dbg("can't open %s: %d(%s)", filename, errno,
+                   strerror(errno));
+
+               return (errno);
+       }
+       /* And immediately close the xfer endpoint */
+       (void) close(fd);
+
+       /*
+        * Open the status endpoint.
+        * If for an Interrupt-IN pipe, need to enable the one transfer mode
+        * by writing USB_EP_INTR_ONE_XFER control to the status endpoint
+        * before opening the xfer endpoint
         */
        if ((ep_type == LIBUSB_TRANSFER_TYPE_INTERRUPT) &&
            (ep_addr & LIBUSB_ENDPOINT_IN)) {
                char    control = USB_EP_INTR_ONE_XFER;
                int     count;
 
-               /* open the status device node for the ep first RDWR */
+               /* Open the status endpoint with RDWR */
                if ((fdstat = open(statfilename, O_RDWR)) == -1) {
                        usbi_dbg("can't open %s RDWR: %d",
                                statfilename, errno);
+
+                       return (errno);
                } else {
                        count = write(fdstat, &control, sizeof (control));
                        if (count != 1) {
@@ -923,37 +955,20 @@ sunos_check_device_and_status_open(struct libusb_device_handle *hdl,
 
                                return (errno);
                        }
-                       /* close status node and open xfer node first */
-                       close (fdstat);
                }
-       }
-
-       /* open the xfer node first in case alt needs to be changed */
-       if (ep_type == LIBUSB_TRANSFER_TYPE_ISOCHRONOUS) {
-               mode = O_RDWR;
-       } else if (ep_addr & LIBUSB_ENDPOINT_IN) {
-               mode = O_RDONLY;
        } else {
-               mode = O_WRONLY;
+               if ((fdstat = open(statfilename, O_RDONLY)) == -1) {
+                       usbi_dbg("can't open %s: %d", statfilename, errno);
+
+                       return (errno);
+               }
        }
 
-       /*
-        * IMPORTANT: must open data xfer node first and then open stat node
-        * Otherwise, it will fail on multi-config or multi-altsetting devices
-        * with "Device Busy" error. See ugen_epxs_switch_cfg_alt() and
-        * ugen_epxs_check_alt_switch() in ugen driver source code.
-        */
+       /* Re-open the xfer endpoint */
        if ((fd = open(filename, mode)) == -1) {
                usbi_dbg("can't open %s: %d(%s)", filename, errno,
                    strerror(errno));
-
-               return (errno);
-       }
-       /* open the status node */
-       if ((fdstat = open(statfilename, O_RDONLY)) == -1) {
-               usbi_dbg("can't open %s: %d", statfilename, errno);
-
-               (void) close(fd);
+               (void) close(fdstat);
 
                return (errno);
        }

diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index dfa2fc9..15f2824 100644 (file)
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 11399
+#define LIBUSB_NANO 11400