Merge "usblib: Wrap USBDEVFS_REAPURBNDELAY ioctl" (96c59d84) · Commits · e / os / android_system_core

libusbhost/include/usbhost/usbhost.h

+3 −2

Original line number	Diff line number	Diff line
		@@ -232,10 +232,11 @@ void usb_request_free(struct usb_request *req);
		/* Submits a read or write request on the specified device */
		int usb_request_queue(struct usb_request *req);

		/* Waits for the results of a previous usb_request_queue operation.
		/* Waits for the results of a previous usb_request_queue operation. timeoutMillis == -1 requests
		* to wait forever.
		* Returns a usb_request, or NULL for error.
		*/
		struct usb_request usb_request_wait(struct usb_device dev);
		struct usb_request usb_request_wait(struct usb_device dev, int timeoutMillis);

		/* Cancels a pending usb_request_queue() operation. */
		int usb_request_cancel(struct usb_request *req);

libusbhost/usbhost.c

+33 −19

Original line number	Diff line number	Diff line
		@@ -14,6 +14,10 @@
		* limitations under the License.
		*/

		#ifndef _GNU_SOURCE
		#define _GNU_SOURCE
		#endif

		// #define DEBUG 1
		#if DEBUG

		@@ -43,6 +47,7 @@
		#include <fcntl.h>
		#include <errno.h>
		#include <ctype.h>
		#include <poll.h>
		#include <pthread.h>

		#include <linux/usbdevice_fs.h>
		@@ -683,30 +688,39 @@ int usb_request_queue(struct usb_request *req)
		return res;
		}

		struct usb_request usb_request_wait(struct usb_device dev)
		struct usb_request usb_request_wait(struct usb_device dev, int timeoutMillis)
		{
		// Poll until a request becomes available if there is a timeout
		if (timeoutMillis > 0) {
		struct pollfd p = {.fd = dev->fd, .events = POLLOUT, .revents = 0};

		int res = poll(&p, 1, timeoutMillis);

		if (res != 1 \|\| p.revents != POLLOUT) {
		D("[ poll - event %d, error %d]\n", p.revents, errno);
		return NULL;
		}
		}

		// Read the request. This should usually succeed as we polled before, but it can fail e.g. when
		// two threads are reading usb requests at the same time and only a single request is available.
		struct usbdevfs_urb *urb = NULL;
		struct usb_request *req = NULL;
		int res = TEMP_FAILURE_RETRY(ioctl(dev->fd, timeoutMillis == -1 ? USBDEVFS_REAPURB :
		USBDEVFS_REAPURBNDELAY, &urb));
		D("%s returned %d\n", timeoutMillis == -1 ? "USBDEVFS_REAPURB" : "USBDEVFS_REAPURBNDELAY", res);

		while (1) {
		int res = ioctl(dev->fd, USBDEVFS_REAPURB, &urb);
		D("USBDEVFS_REAPURB returned %d\n", res);
		if (res < 0) {
		if(errno == EINTR) {
		continue;
		}
		D("[ reap urb - error ]\n");
		D("[ reap urb - error %d]\n", errno);
		return NULL;
		} else {
		D("[ urb @%p status = %d, actual = %d ]\n",
		urb, urb->status, urb->actual_length);
		req = (struct usb_request*)urb->usercontext;
		D("[ urb @%p status = %d, actual = %d ]\n", urb, urb->status, urb->actual_length);

		struct usb_request req = (struct usb_request)urb->usercontext;
		req->actual_length = urb->actual_length;
		}
		break;
		}

		return req;
		}
		}

		int usb_request_cancel(struct usb_request *req)
		{