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11992b4100
ERR051725:
USB: With the USB controller configured as device mode, Clearing the RS
bit of USBCMD register fails to cause USB device to be detached
Description
1. USB controller working as high speed device mode with USB gadget
function enabled
2. Cable plugged into USB host
3. Use case is software-controlled detach from USB device side
The expected result is device side terminations removed, increase in USB
signal amplitude, USB host detect device is detached. But the issue is
that the clear RS bit of USBCMD register cannot cause device detach event.
Workaround
- Use the below steps to detach from the host:
write USBCMD.RS = 0b
write CTRL2[7:6] = 01b
write CTRL2[8] = 1b
- As CTRL2[8] is set at detach case, so attach the steps should add clear
CTRL2[8]:
write USBCMD.RS = 1b
write CTRL2[8] = 0b
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Link: https://lore.kernel.org/r/20250614125645.207732-4-xu.yang_2@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.