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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, stable <stable@kernel.org>,
        Sven Peter <sven@svenpeter.dev>,
        William Wu <william.wu@rock-chips.com>
Subject: [PATCH 5.15 038/148] usb: dwc3: core: leave default DMA if the controller does not support 64-bit DMA
Date:   Mon, 26 Sep 2022 12:11:12 +0200
Message-Id: <20220926100757.451004057@linuxfoundation.org>
In-Reply-To: <20220926100756.074519146@linuxfoundation.org>
References: <20220926100756.074519146@linuxfoundation.org>
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From: William Wu <william.wu@rock-chips.com>

commit 91062e663b261815573ce00967b1895a99e668df upstream.

On some DWC3 controllers (e.g. Rockchip SoCs), the DWC3 core
doesn't support 64-bit DMA address width. In this case, this
driver should use the default 32-bit mask. Otherwise, the DWC3
controller will break if it runs on above 4GB physical memory
environment.

This patch reads the DWC_USB3_AWIDTH bits of GHWPARAMS0 which
used for the DMA address width, and only configure 64-bit DMA
mask if the DWC_USB3_AWIDTH is 64.

Fixes: 45d39448b4d0 ("usb: dwc3: support 64 bit DMA in platform driver")
Cc: stable <stable@kernel.org>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: William Wu <william.wu@rock-chips.com>
Link: https://lore.kernel.org/r/20220901083446.3799754-1-william.wu@rock-chips.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/usb/dwc3/core.c |   13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1570,12 +1570,6 @@ static int dwc3_probe(struct platform_de
 
 	dwc3_get_properties(dwc);
 
-	if (!dwc->sysdev_is_parent) {
-		ret = dma_set_mask_and_coherent(dwc->sysdev, DMA_BIT_MASK(64));
-		if (ret)
-			return ret;
-	}
-
 	dwc->reset = devm_reset_control_array_get_optional_shared(dev);
 	if (IS_ERR(dwc->reset))
 		return PTR_ERR(dwc->reset);
@@ -1612,6 +1606,13 @@ static int dwc3_probe(struct platform_de
 	platform_set_drvdata(pdev, dwc);
 	dwc3_cache_hwparams(dwc);
 
+	if (!dwc->sysdev_is_parent &&
+	    DWC3_GHWPARAMS0_AWIDTH(dwc->hwparams.hwparams0) == 64) {
+		ret = dma_set_mask_and_coherent(dwc->sysdev, DMA_BIT_MASK(64));
+		if (ret)
+			goto disable_clks;
+	}
+
 	spin_lock_init(&dwc->lock);
 	mutex_init(&dwc->mutex);