Hi Peter,
I don't really see the problem.
Ether kernel had the driver loaded, or there is other app. If there is
kernel I detach the kernel driver and the device is claimed.
If other app is using the device then I will only try to claim. (Which
will fail)
I can only see the "racy" when 2 applications are concurrently trying
to claim the device, in which case not even your solution
is perfect :-)
Could you please be more specific with the problem?
Md
On Mon, Apr 23, 2012 at 7:11 PM, Peter Stuge <peter(a)stuge.se> wrote:
Michal Demin wrote:
Subject: [PATCH 1/2] Detach the device kernel
driver when kernel driver loaded.
..
@@ -689,6 +690,15 @@ int rtlsdr_open(rtlsdr_dev_t
**out_dev, uint32_t index)
libusb_free_device_list(list, 0);
+ if (libusb_kernel_driver_active(dev->devh, 0)) {
+ // reattach later
+ dev->reattach = 1;
+ if (libusb_detach_kernel_driver(dev->devh, 0)) {
+ fprintf(stderr, "Error detaching kernel driver \n");
+ goto err;
+ }
+ }
+
r = libusb_claim_interface(dev->devh, 0);
if (r < 0) {
fprintf(stderr, "usb_claim_interface error %d\n", r);
This is racy. It's better to call libusb_detach_kernel_driver() when
libusb_claim_interface() returns an error.
//Peter