Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Krishna Kurapati <quic_kriskura@quicinc.com>
To:     Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        "Andy Gross" <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        "Konrad Dybcio" <konrad.dybcio@linaro.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Felipe Balbi <balbi@kernel.org>
CC:     <linux-usb@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <quic_pkondeti@quicinc.com>, <quic_ppratap@quicinc.com>,
        <quic_wcheng@quicinc.com>, <quic_jackp@quicinc.com>,
        <quic_harshq@quicinc.com>,
        Krishna Kurapati <quic_kriskura@quicinc.com>
Subject: [RFC v4 3/5] usb: dwc3: core: Do not setup event buffers for host only controllers
Date:   Sun, 15 Jan 2023 17:11:44 +0530
Message-ID: <20230115114146.12628-4-quic_kriskura@quicinc.com>
In-Reply-To: <20230115114146.12628-1-quic_kriskura@quicinc.com>
References: <20230115114146.12628-1-quic_kriskura@quicinc.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
Precedence: bulk

Multiport controllers being host-only capable do not have GEVNTADDR
HI/LO, SIZE, COUNT reigsters present. Accsesing them to setup event
buffers during core_init can cause an SMMU Fault. Avoid event buffers
setup if the GHWPARAMS0 tells that the controller is host-only.

Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
---
 drivers/usb/dwc3/core.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 7e0a9a598dfd..f61ebddaecc0 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -871,9 +871,12 @@ static void dwc3_clk_disable(struct dwc3 *dwc)
 
 static void dwc3_core_exit(struct dwc3 *dwc)
 {
-	int i;
+	int		i;
+	unsigned int	hw_mode;
 
-	dwc3_event_buffers_cleanup(dwc);
+	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
+	if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST)
+		dwc3_event_buffers_cleanup(dwc);
 
 	usb_phy_set_suspend(dwc->usb2_phy, 1);
 	usb_phy_set_suspend(dwc->usb3_phy, 1);
@@ -1246,10 +1249,12 @@ static int dwc3_core_init(struct dwc3 *dwc)
 		}
 	}
 
-	ret = dwc3_event_buffers_setup(dwc);
-	if (ret) {
-		dev_err(dwc->dev, "failed to setup event buffers\n");
-		goto err4;
+	if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST) {
+		ret = dwc3_event_buffers_setup(dwc);
+		if (ret) {
+			dev_err(dwc->dev, "failed to setup event buffers\n");
+			goto err4;
+		}
 	}
 
 	/*
@@ -1886,7 +1891,7 @@ static int dwc3_probe(struct platform_device *pdev)
 	struct resource		*res, dwc_res;
 	struct dwc3		*dwc;
 	int			ret, i;
-
+	unsigned int		hw_mode;
 	void __iomem		*regs;
 
 	dwc = devm_kzalloc(dev, sizeof(*dwc), GFP_KERNEL);
@@ -2063,7 +2068,9 @@ static int dwc3_probe(struct platform_device *pdev)
 err5:
 	dwc3_debugfs_exit(dwc);
 
-	dwc3_event_buffers_cleanup(dwc);
+	hw_mode = DWC3_GHWPARAMS0_MODE(dwc->hwparams.hwparams0);
+	if (hw_mode != DWC3_GHWPARAMS0_MODE_HOST)
+		dwc3_event_buffers_cleanup(dwc);
 
 	usb_phy_set_suspend(dwc->usb2_phy, 1);
 	usb_phy_set_suspend(dwc->usb3_phy, 1);
-- 
2.39.0