From 07903626d98853e605fe63e5ce149f1b7314bbea Mon Sep 17 00:00:00 2001
From: Rohith Kollalsi <quic_rkollals@quicinc.com>
Date: Thu, 14 Jul 2022 10:26:25 +0530
Subject: [PATCH] usb: dwc3: core: Do not perform GCTL_CORE_SOFTRESET during
bootup
Git-commit: 07903626d98853e605fe63e5ce149f1b7314bbea
References: bsc#1220628 CVE-2021-46941
Patch-mainline: v6.0-rc1
According to the programming guide, it is recommended to
perform a GCTL_CORE_SOFTRESET only when switching the mode
from device to host or host to device. However, it is found
that during bootup when __dwc3_set_mode() is called for the
first time, GCTL_CORESOFTRESET is done with suspendable bit(BIT 17)
of DWC3_GUSB3PIPECTL set. This some times leads to issues
like controller going into bad state and controller registers
reading value zero. Until GCTL_CORESOFTRESET is done and
run/stop bit is set core initialization is not complete.
Setting suspendable bit of DWC3_GUSB3PIPECTL and then
performing GCTL_CORESOFTRESET is therefore not recommended.
Avoid this by only performing the reset if current_dr_role is set,
that is, when doing subsequent role switching.
Fixes: f88359e1588b ("usb: dwc3: core: Do core softreset when switch mode")
Signed-off-by: Rohith Kollalsi <quic_rkollals@quicinc.com>
Link: https://lore.kernel.org/r/20220714045625.20377-1-quic_rkollals@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/usb/dwc3/core.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -148,8 +148,11 @@ static void __dwc3_set_mode(struct work_
break;
}
- /* For DRD host or device mode only */
- if (dwc->desired_dr_role != DWC3_GCTL_PRTCAP_OTG) {
+ /*
+ * When current_dr_role is not set, there's no role switching.
+ * Only perform GCTL.CoreSoftReset when there's DRD role switching.
+ */
+ if (dwc->current_dr_role && dwc->desired_dr_role != DWC3_GCTL_PRTCAP_OTG) {
reg = dwc3_readl(dwc->regs, DWC3_GCTL);
reg |= DWC3_GCTL_CORESOFTRESET;
dwc3_writel(dwc->regs, DWC3_GCTL, reg);