[PATCH V2 3/4] usb: dwc3: gadget: Don't send unintended link state change

[Mattijs Korpershoek]

Hi Chris,

Thank you for the patch.

On Thu, Jan 15, 2026 at 17:01, Chris Morgan <macroalpha82 at gmail.com> wrote:

> From: Chris Morgan <macromorgan at hotmail.com>
>
> DCTL.ULSTCHNGREQ is a write-only field. When doing a read-modify-write
> to DCTL, the driver must make sure that there's no unintended link state
> change request from whatever is read from DCTL.ULSTCHNGREQ. Set link
> state change to no-action when the driver writes to DCTL.
>
> Note that this patch was submitted upstream in Linux in 2020 [1],
> and I've confirmed I need it in U-Boot to enable gadget mode.
>
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/patch/drivers/usb/dwc3?id=5b738211fb59e114727381d07c647a77c0010996
>
> Signed-off-by: Thinh Nguyen <thinhn at synopsys.com>
> Signed-off-by: Chris Morgan <macromorgan at hotmail.com>

Reviewed-by: Mattijs Korpershoek <mkorpershoek at kernel.org>

> ---
>  drivers/usb/dwc3/gadget.c | 16 +++++++---------
>  drivers/usb/dwc3/gadget.h | 14 ++++++++++++++
>  2 files changed, 21 insertions(+), 9 deletions(-)
>