问题描述:

I am developing an application using the new USB Host API on Android 3.1 and have been searching hi-and-lo for anything about opening and closing pipes on endpoints.

USB specifications state that, in order to perform a bulk transfer on an endpoint, you must first open a pipe on that endpoint. Trouble is there is no openPipe() method on the UsbEndpoint class in Android.

Maybe calling bulkTransfer - or queuing a UsbRequest on your desired endpoint - automatically handles the opening and closing of the underlying pipe... but there is no documenation regarding this. Or perhaps there is a way to send a control transfer to open my desired pipe?

It seems odd that the Android API reference makes no mention of USB Pipes at all considering they are an important concept in USB specifications... and pretty much every other API (Windows, Java, Oracle) has open / close pipe methods that can be used.

Anyone have insight here?

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