On Mon, Aug 16, 2021 at 08:52:06AM +0800, Peter Chen wrote:

On 21-08-10 15:02:28, Jeaho Hwang wrote:

quoted

hw_ep_prime sometimes fails if irq occurs while it rus on RT kernel.
to prevent local_irq_save should keep the function from irqs.

I am not sure where is the best to submit this patch, between RT and USB
community so sending to both. thanks.

Greg, do you have any suggestions about it, the RT kernel schedules the interrupt
handler (top-half) out which causes the USB hardware atomic sequences are broken,
these hardware operations needs to be executed within limited time.

The RT kernel does its scheduling based on priorities.  If the 
interrupt handler is scheduled out, it's because some other process 
with a higher priority needs to run.  The answer should be to increase 
the handler's priority.

Alan Stern