usb: dwc2: gadget: remove D+ pull-up while no vbus with usb-role-switch

stable inclusion
from stable-v5.10.138
commit 9a87f33f1dd0484306987cf742944425057e109b
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I60QFD

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=9a87f33f1dd0484306987cf742944425057e109b



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[ Upstream commit db638c65 ]

When using usb-role-switch, D+ pull-up is set as soon as DTCL_SFTDISCON is
cleared, whatever the vbus valid signal state is. The pull-up should not
be set when vbus isn't present (this is determined by the drd controller).

This patch ensures that B-Session (so Peripheral role + vbus valid signal)
is valid before clearing the DCTL_SFTDISCON bit when role switch is used.
Keep original behavior when usb-role-switch isn't used.

Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Link: https://lore.kernel.org/r/20220622160717.314580-1-fabrice.gasnier@foss.st.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>