usb: dwc3: core: leave default DMA if the controller does not support 64-bit DMA

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>

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 8c8e326..d0237b3 100644 (file)
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1752,12 +1752,6 @@ static int dwc3_probe(struct platform_device *pdev)
 
        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);
@@ -1823,6 +1817,13 @@ static int dwc3_probe(struct platform_device *pdev)
        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);