interrupt

I'm trying to connect a USB-Device ( build by myself ) to communicate with my development board ( ODROID-X ) Unfortunately, the examples are very little, as far as the asynchronous communication. I'd some problems with the interrupt driven data exchange - how to build the connection by using the asynchronous interrupt mode? In one direction, the transmission was possible ... but in both it doesn't work. Is there an example like this: send a ByteBuffer with endpoint_OUT get a message from device on endpoint_IN both in interrupt mode. Thanks a lot for your support. Hardy Neil Perhaps I am

I am reading Linux Kernel Development recently, and I have a few questions related to disabling preemption. In the "Interrupt Control" section of chapter 7, it says: Moreover, disabling interrupts also disables kernel preemption. I also read from the book that kernel preemption can occur in the follow cases: When an interrupt handler exits, before returning to kernel-space. When kernel code becomes preemptible again. If a task in the kernel explicitly calls schedule() If a task in ther kernel blocks (which results in a call to schedule()) But I can't relate disabling interrupts with these

I know that there are process context and interrupt context but I don't understand when executing softirq or tasklet, which context is it run under. I have seen some people use the term "bottom-halves context", if there's such term, what's the difference comparing with the others. Another question to softirq and tasklet is that why sleep are not allowed during execution?? Can anyone help me identify these questions, thanks!! The softirq and tasklet are both kind of bottom-halves mechanism. Sleep is not allowed becuase they run under interrupt context not process context. If sleep is allowed,

I'm reading about the difference in assembly between x86 and x64. On x86, the system call number is placed in eax , then int 80h is executed to generate a software interrupt. But on x64, the system call number is placed in rax , then syscall is executed. I'm told that syscall is lighter and faster than generating a software interrupt. Why it is faster on x64 than x86, and can I make a system call on x64 using int 80h ? mikyra General part EDIT: Linux irrelevant parts removed While not totally wrong, narrowing down to int 0x80 and syscall oversimplifies the question as with sysenter there is at

This is a short question. At some point my thread understand that it should suicide. What is the best way to do it: Thread.currentThread().interrupt(); return; By the way, why in the first case we need to use currentThread ? Is Thread does not refer to the current thread? If you want to terminate the thread , then just returning is fine. You do NOT need to call Thread.currentThread().interrupt() (it will not do anything bad though. It's just that you don't need to.) This is because interrupt() is basically used to notify the owner of the thread (well, not 100% accurate, but sort of). Because

I am studying Intel Protected Mode. I found that Call Gate, Interrupt Gate, Trap Gate are almost the same. In fact, besides that Call Gate has the fields for parameter counter, and that these 3 gates have different type fields, they are identical in all other fields. As to their functions, they are all used to transfer code control into some procedure within some code segment. I am wondering, since these 3 gates all contain the information needed for the call across privilege boundaries. Why do we need 3 kinds of them? Isn't 1 just good enough? Thanks for your time and response. Update 1 A