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dmitrystu / libusb_stm32

Lightweight USB device Stack for STM32 microcontrollers
Apache License 2.0
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how to decide if a usb device is connected and configured? #76

Closed mttbx closed 3 years ago

mttbx commented 3 years ago

I want to use polling method for get message from the usb device. And I can't just use usbd_ep_read/usbd_ep_write methods because it may corrupt the configure process. How to decide if a usb device is connected and configured?

mttbx commented 3 years ago

@dmitrystu Can you answer my question? And I find that it may sometimes crush linux kernel, I don't know why, but I'm trying to figure it out.

dzarda commented 3 years ago

How about using the cdc_setconf() callback?

dmitrystu commented 3 years ago

Sorry, I'm temporary away from keyboard. I'll answer to you ASAP.

mttbx commented 3 years ago

@dzarda Thank you, I'll try. I found that if I restart my board while the host communicating with it, the linux kernel will crush. I think this might be a issue of linux kernel. Is it any way to avoid this kind of thing?

[   75.601033] Call Trace:
[   75.601034]  <IRQ>
[   75.601038]  queue_work_on+0x3b/0x50
[   75.601042]  acm_write_bulk+0x70/0x80 [cdc_acm]
[   75.601045]  __usb_hcd_giveback_urb+0x7a/0x120
[   75.601047]  usb_giveback_urb_bh+0xa1/0x100
[   75.601050]  tasklet_action_common.isra.0+0x60/0x110
[   75.601052]  tasklet_action+0x22/0x30
[   75.601054]  __do_softirq+0xe1/0x2d6
[   75.601056]  asm_call_irq_on_stack+0x12/0x20
[   75.601057]  </IRQ>
dzarda commented 3 years ago

Wow nice :D Perhaps a VM might avoid the crash?

Also try a newer kernel

mttbx commented 3 years ago

I'm using the newest kernel. VM might help.