ef3d343254
Previously, adb was assuming a fixed maximum packet size of 1024 bytes
(the value for an endpoint connected via USB 3.0). When connected to an
endpoint that has an actual maximum packet size of 512 bytes (i.e.
every single device over USB 2.0), the following could occur:
device sends amessage with 512 byte payload
client reads amessage
client tries to read payload with a length of 1024
In this scenario, the kernel will block, waiting for an additional
packet which won't arrive until something else gets sent across the
wire, which will result in the previous read failing, and the new
packet being dropped.
Bug: http://b/37783561
Test: python test_device.py on linux/darwin, with native/libusb
Change-Id: I556f5344945e22dd1533b076f662a97eea24628e
56 lines
2.1 KiB
C++
56 lines
2.1 KiB
C++
/*
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* Copyright (C) 2017 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include <android-base/logging.h>
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#include "usb.h"
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void usb_init() {
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if (should_use_libusb()) {
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LOG(DEBUG) << "using libusb backend";
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libusb::usb_init();
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} else {
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LOG(DEBUG) << "using native backend";
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native::usb_init();
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}
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}
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int usb_write(usb_handle* h, const void* data, int len) {
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return should_use_libusb()
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? libusb::usb_write(reinterpret_cast<libusb::usb_handle*>(h), data, len)
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: native::usb_write(reinterpret_cast<native::usb_handle*>(h), data, len);
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}
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int usb_read(usb_handle* h, void* data, int len) {
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return should_use_libusb()
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? libusb::usb_read(reinterpret_cast<libusb::usb_handle*>(h), data, len)
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: native::usb_read(reinterpret_cast<native::usb_handle*>(h), data, len);
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}
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int usb_close(usb_handle* h) {
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return should_use_libusb() ? libusb::usb_close(reinterpret_cast<libusb::usb_handle*>(h))
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: native::usb_close(reinterpret_cast<native::usb_handle*>(h));
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}
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void usb_kick(usb_handle* h) {
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should_use_libusb() ? libusb::usb_kick(reinterpret_cast<libusb::usb_handle*>(h))
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: native::usb_kick(reinterpret_cast<native::usb_handle*>(h));
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}
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size_t usb_get_max_packet_size(usb_handle* h) {
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return should_use_libusb()
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? libusb::usb_get_max_packet_size(reinterpret_cast<libusb::usb_handle*>(h))
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: native::usb_get_max_packet_size(reinterpret_cast<native::usb_handle*>(h));
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}
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