git: 6847ea50196f - main - Improve handling of USB device re-open in the LibUSB v1.x API.

[Hans Petter Selasky]

The branch main has been updated by hselasky:

URL: https://cgit.FreeBSD.org/src/commit/?id=6847ea50196f1a685be408a24f01cb8d407da19c

commit 6847ea50196f1a685be408a24f01cb8d407da19c
Author:     Hans Petter Selasky <hselasky at FreeBSD.org>
AuthorDate: 2021-06-11 15:06:10 +0000
Commit:     Hans Petter Selasky <hselasky at FreeBSD.org>
CommitDate: 2021-06-11 15:06:44 +0000

    Improve handling of USB device re-open in the LibUSB v1.x API.
    
    Make sure the "device_is_gone" flag is cleared after every successful open,
    so that the "device_is_gone" flag doesn't persist forever.
    
    Found by:       sergii.dmytruk at 3mdeb.com
    PR:             256296
    MFC after:      1 week
    Sponsored by:   Mellanox Technologies // NVIDIA Networking
---
 lib/libusb/libusb10.c    |  9 +++++++++
 lib/libusb/libusb10_io.c | 12 ++++++++++--
 lib/libusb/libusb20.c    |  5 +++++
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/lib/libusb/libusb10.c b/lib/libusb/libusb10.c
index 1c45b87d8f0b..ffe0cf3f366a 100644
--- a/lib/libusb/libusb10.c
+++ b/lib/libusb/libusb10.c
@@ -529,6 +529,15 @@ libusb_open(libusb_device *dev, libusb_device_handle **devh)
 		libusb_unref_device(dev);
 		return (LIBUSB_ERROR_NO_MEM);
 	}
+
+	/*
+	 * Clear the device gone flag, in case the device was opened
+	 * after a re-attach, to allow new transaction:
+	 */
+	CTX_LOCK(ctx);
+	dev->device_is_gone = 0;
+	CTX_UNLOCK(ctx);
+
 	libusb10_add_pollfd(ctx, &dev->dev_poll, pdev, libusb20_dev_get_fd(pdev), POLLIN |
 	    POLLOUT | POLLRDNORM | POLLWRNORM);
 
diff --git a/lib/libusb/libusb10_io.c b/lib/libusb/libusb10_io.c
index 53f5b040436d..0e32fc31c8e0 100644
--- a/lib/libusb/libusb10_io.c
+++ b/lib/libusb/libusb10_io.c
@@ -165,8 +165,16 @@ libusb10_handle_events_sub(struct libusb_context *ctx, struct timeval *tv)
 				err = libusb20_dev_process(ppdev[i]);
 
 				if (err) {
-					/* set device is gone */
-					dev->device_is_gone = 1;
+					/*
+					 * When the device is opened
+					 * set the "device_is_gone"
+					 * flag. This prevents the
+					 * client from submitting new
+					 * USB transfers to a detached
+					 * device.
+					 */
+					if (ppdev[i]->is_opened)
+						dev->device_is_gone = 1;
 
 					/* remove USB device from polling loop */
 					libusb10_remove_pollfd(dev->ctx, &dev->dev_poll);
diff --git a/lib/libusb/libusb20.c b/lib/libusb/libusb20.c
index 6c2bf721bea9..4323552b83ad 100644
--- a/lib/libusb/libusb20.c
+++ b/lib/libusb/libusb20.c
@@ -608,6 +608,11 @@ libusb20_dev_close(struct libusb20_device *pdev)
 
 	pdev->is_opened = 0;
 
+	/*
+	 * Make sure libusb20_tr_get_pointer() fails:
+	 */
+	pdev->nTransfer = 0;
+
 	/* 
 	 * The following variable is only used by the libusb v0.1
 	 * compat layer: