linux-kernel - [PATCH 5.3 03/21] phy: renesas: rcar-gen3-usb2: Disable clearing VBUS in over-current

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190919214700.340652750@linuxfoundation.org>
Date:   Fri, 20 Sep 2019 00:03:04 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>,
        Kishon Vijay Abraham I <kishon@...com>
Subject: [PATCH 5.3 03/21] phy: renesas: rcar-gen3-usb2: Disable clearing VBUS in over-current

From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>

commit e6839c31a608e79f2057fab987dd814f5d3477e6 upstream.

The hardware manual should be revised, but the initial value of
VBCTRL.OCCLREN is set to 1 actually. If the bit is set, the hardware
clears VBCTRL.VBOUT and ADPCTRL.DRVVBUS registers automatically
when the hardware detects over-current signal from a USB power switch.
However, since the hardware doesn't have any registers which
indicates over-current, the driver cannot handle it at all. So, if
"is_otg_channel" hardware detects over-current, since ADPCTRL.DRVVBUS
register is cleared automatically, the channel cannot be used after
that.

To resolve this behavior, this patch sets the VBCTRL.OCCLREN to 0
to keep ADPCTRL.DRVVBUS even if the "is_otg_channel" hardware
detects over-current. (We assume a USB power switch itself protects
over-current and turns the VBUS off.)

This patch is inspired by a BSP patch from Kazuya Mizuguchi.

Fixes: 1114e2d31731 ("phy: rcar-gen3-usb2: change the mode to OTG on the combined channel")
Cc: <stable@...r.kernel.org> # v4.5+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@...esas.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@...com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/phy/renesas/phy-rcar-gen3-usb2.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
+++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
@@ -61,6 +61,7 @@
 					 USB2_OBINT_IDDIGCHG)

 /* VBCTRL */
+#define USB2_VBCTRL_OCCLREN		BIT(16)
 #define USB2_VBCTRL_DRVVBUSSEL		BIT(8)

 /* LINECTRL1 */
@@ -374,6 +375,7 @@ static void rcar_gen3_init_otg(struct rc
 	writel(val, usb2_base + USB2_LINECTRL1);

 	val = readl(usb2_base + USB2_VBCTRL);
+	val &= ~USB2_VBCTRL_OCCLREN;
 	writel(val | USB2_VBCTRL_DRVVBUSSEL, usb2_base + USB2_VBCTRL);
 	val = readl(usb2_base + USB2_ADPCTRL);
 	writel(val | USB2_ADPCTRL_IDPULLUP, usb2_base + USB2_ADPCTRL);