From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>,
        Amelie Delaunay <amelie.delaunay@foss.st.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 449/575] usb: dwc2: drd: reset current session before setting the new one
Date:   Mon, 15 Nov 2021 18:02:54 +0100
Message-Id: <20211115165359.277494223@linuxfoundation.org>
In-Reply-To: <20211115165343.579890274@linuxfoundation.org>
References: <20211115165343.579890274@linuxfoundation.org>
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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