[PATCH 5.15 654/917] usb: dwc2: drd: reset current session before setting the new one

Greg Kroah-Hartman
2021-11-16T00:33:18Z

From: Amelie Delaunay <amelie.delaunay@foss.st.com>

[ Upstream commit 1ad707f559f7cb12c64f3d7cb37f0b1ea27c1058 ]

If role is changed without the "none" step, A- and B- valid session could
be set at the same time. It is an issue.
This patch resets A-session if role switch sets B-session, and resets
B-session if role switch sets A-session.
Then, it is possible to change the role without the "none" step.

Fixes: 17f934024e84 ("usb: dwc2: override PHY input signals with usb role switch support")
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com>
Link: https://lore.kernel.org/r/20211005095305.66397-4-amelie.delaunay@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/dwc2/drd.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/usb/dwc2/drd.c b/drivers/usb/dwc2/drd.c
index 99672360f34b0..aa6eb76f64ddc 100644
--- a/drivers/usb/dwc2/drd.c
+++ b/drivers/usb/dwc2/drd.c
@@ -40,6 +40,7 @@ static int dwc2_ovr_avalid(struct dwc2_hsotg *hsotg, bool valid)
(!valid && !(gotgctl & GOTGCTL_ASESVLD)))
return -EALREADY;

+ gotgctl &= ~GOTGCTL_BVALOVAL;
if (valid)
gotgctl |= GOTGCTL_AVALOVAL | GOTGCTL_VBVALOVAL;
else
@@ -58,6 +59,7 @@ static int dwc2_ovr_bvalid(struct dwc2_hsotg *hsotg, bool valid)
(!valid && !(gotgctl & GOTGCTL_BSESVLD)))
return -EALREADY;

+ gotgctl &= ~GOTGCTL_AVALOVAL;
if (valid)
gotgctl |= GOTGCTL_BVALOVAL | GOTGCTL_VBVALOVAL;
else
--
2.33.0