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PC running slow?
In this blog post, we will identify some of the possible reasons that could lead to the libusb-win32 callback and then we will suggest possible solutions that you can try to solve for this problem.
The following information is based on the libusb-0.1 API Forms (http://libusb.sourceforge.net/doc/) by Johannes Erdfelt, but enhanced with libusb-win32 specific information.
Foreword
The purpose of this document is to explain the libusb-win32 API and help you use it for USB compatible applications. All suggestions, corrections, and comments regarding this document should be sent to any libusb-win32 developer mailing list.
This documentation provides an overview of how the libusb v0 the.1 API works and how it relates to USB. It is assumed that the reader has a good understanding of USB 2.0 styles. The USB 2.0 specification can be obtained from the Implementers USB Forum website (http://www.usb.org). libusb-0.Works 1 on Linux, FreeBSD, NetBSD, OpenBSD; Darwin/MacOS X and Solaris. libusb-win32 is an API that is compatible with libusb-0.1 but also contains new features.
This is an external For API application to use. This API is quite lightweight and is designed according to the USB 2.0 specification.
The libusb API associates an open device with specific software. This means that if you want to claim multiple interfaces on a device, you need to open the device multiple times.o time to get the usb_dev_handle for each interface you want to interact with. Don’t forget to call usb_claim_interface().
libusb uses both abstract and abstract structs for portability.
All near-original libusb v0.1 functions are synchronous, i.e. H-functions typically block and wait for the operation to complete or time out before resuming execution to the calling application. libusb-win32 exposes some APIs asynchronously. libusb-1.0 has even more asynchronous API support.
In libusb v0.1, two types of come values are used. The first is the handle returned by the usb_open() function. Second, it’s an int. For all tasks that return an integer, >= 9 means success and <0 means conditional failure.
On Linux libusb-0.1 (which can only support the synchronous API), a timeout value of 0 means infinity. libusb-win32 version 1.2.4.7 and will probably follow later for the synchronous API. Until then, libusb-0.1 behaves differently than Linux.
Because Windows (same for Linux and Mac OS X) is not an RTOS, it is not recommended to use a very smallMultiple timeout values, such as 10ms or 100ms.
Synchronous Transfer Timeout Warnings
How the synchronous API works:
1) Sends a read request to the driver
2) positive wait for a given timeout using WaitForSingleObject()
a. If the timeout expires, reschedule the channel interrupt request and return -116
B. If the wait was successful, get wrap dividends via GetOverlappedResults() and return an error or the length of the traversal.
So if the translation ends soon after and expires in 2a, my entire translation is lost.
Currently, there are several ways to avoid this:
1) Use these special async transfer functions and usb_reap_async_nocancel()
2) Use synchronization transfer functions in their separate threads and
Always use INFINITE for timeout.
Standard error codes from Crt wdk errno.h to MinGW’s explanation are listed on the right. Note that all error limits listed below apply. Features
They make up the core of libusb. They are used in all practices using libusb.
This group of applications is intended for the device. It opens and closes the device showing standard USB operations such as setting some configuration, clearing settings, suspending and resetting the device. It also provides OS number operations as such to query and reduce
Interfaces.
This set of functions allows applications to send messages to the controller’s default channel.
This feature set allows applications to bulk send or receive data across channels.
This set of functions allows applications to send certain data through interrupt channels.
libusb-win32 supports isochronous transfers through its asynchronous API. The libusb-win32 asynchronous API also supports other forwarding mechanisms such as control redirection, bulk interrupt forwarding, and forwarding.
These functions are not portable. You can open part of the USB API in the OS, or maybe more, but not all. They are all marked with the string _np at the end of most function names.
A C preprocessor macro is definitely defined whenThe function is observed. The LIBUSB_HAS_ form prefixed with the function name without the first “usb_” in uppercase. Example: if usb_get_driver_np is properly implemented, then LIBUSB_HAS_GET_DRIVER_NP is set.
libwdi (http://libwdi.sf.net/), WDK DIFX (http://msdn.microsoft.com/en-us/library/ff544838%28v=VS.85%29.Canaspx). used for this purpose. You can combine libwdi/DIFx with installers such as Inno Setup (http://www.jrsoftware.org/isinfo.php) or NSIS (http://nsis.sourceforge.net/).
Some of the non-intuitive parts of libusb v0.1 are simple, but will probably be easier to understand with a few examples.
Before you can start a dialogue with a device, you need to find it. After that, all buses are in addition, then all devices are above all tires:
After that, a practical application must manually iterate through all typical tires and devices, and then configure the device according to the criteria that are definitely needed:
/* Connection timed out */# define ETRANSFER_TIMEDOUT 116
PC running slow?
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Bug Fix En Libusb-win32 Callback Fix
Устранение ошибок и исправление обратного вызова Libusb-win32
Bugfix Och Libusb-win32 Callback Fix
Correção De Bug E Correção De Retorno De Chamada Libusb-win32
Ripristino Bug E Correzione Della Richiamata Libusb-win32
Naprawa Błędu I Poprawka Wywołania Zwrotnego Libusb-win32
버그 수정 및 Libusb-win32 콜백 수정
Corrección De Error Y Corrección De Devolución De Llamada De Libusb-win32
Correction De Bug Et Correction De Rappel Libusb-win32
