[Core] ChibiOS: Fix USB bus disconnect handling #18566
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usb_disconnect() previously only stopped the USB driver but didn't disconnect the device from USB bus. This is a problem with split keyboards that fail to enumerate on bootup but are actually connected to a USB bus. This can happen in the case that a short `SPLIT_USB_TIMEOUT` is used but it takes longer to enumerate with the host system correctly. In this condition the host system would still try to enumerate with the keyboard, as it still recognizes it as a connected device, but never succeed as we already disabled the USB driver. This in turn prevents some systems to boot-up correctly or at least slow down the boot process until the device is finally rejected by the host USB stack. A drive-by fix is the case for rebooting a keyboard without a physical reconnect and not stopping the USB driver before starting it again - which is a violation of ChibiOS state model for the USB driver.
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zvecr
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Oct 2, 2022
daskygit
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Oct 2, 2022
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Thanks for the quick tests and approvals 🎉 I'll wait for the ci build and merge afterwards. |
KarlK90
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Description
usb_disconnect()previously only stopped the USB driver but didn't disconnect the device from USB bus. This is a problem with split keyboards that fail to enumerate on bootup but are actually connected to a USB bus. This can happen in the case that a shortSPLIT_USB_TIMEOUTis used but it takes longer to enumerate with the host system correctly. In this condition the host system would still try to enumerate with the keyboard, as it still recognizes it as a connected device, but never succeed as we already disabled the USB driver. This in turn prevents some systems to boot-up correctly or at least slow down the boot process until the device is finally rejected by the host USB stack.A drive-by fix is the case for rebooting a keyboard without a physical reconnect and not stopping the USB driver before starting it again - which is a violation of ChibiOS state model for the USB driver.
Demo: RP2040 split keyboard that fails to enumerate on boot
With the fix the device is disconnected properly
Without the fix the device is not disconnected and the host tries to enumerate until finally giving up
Types of Changes
Issues Fixed or Closed by This PR
Checklist