Re: [PATCH] drivers/usb/dwc3: fix PCI parent check

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Wed, Nov 05, 2025, Punit Agrawal wrote:
> From: Jamie Iles <jamie.iles@oss.qualcomm.com>
> 
> The sysdev_is_parent check was being used to infer PCI devices that have
> the DMA mask set from the PCI capabilities, but sysdev_is_parent is also
> used for non-PCI ACPI devices in which case the DMA mask would be the
> bus default or as set by the _DMA method.
> 
> Without this fix the DMA mask would default to 32-bits and so allocation
> would fail if there was no DRAM below 4GB.
> 
> Fixes: 47ce45906ca9 ("usb: dwc3: leave default DMA for PCI devices")
> Signed-off-by: Jamie Iles <jamie.iles@oss.qualcomm.com>
> Signed-off-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com>

We should Cc stable also.

> ---
>  drivers/usb/dwc3/core.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index ae140c356295..c2ce2f5e60a1 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -25,6 +25,7 @@
>  #include <linux/of.h>
>  #include <linux/of_graph.h>
>  #include <linux/acpi.h>
> +#include <linux/pci.h>
>  #include <linux/pinctrl/consumer.h>
>  #include <linux/pinctrl/devinfo.h>
>  #include <linux/reset.h>
> @@ -2241,7 +2242,7 @@ int dwc3_core_probe(const struct dwc3_probe_data *data)
>  	dev_set_drvdata(dev, dwc);
>  	dwc3_cache_hwparams(dwc);
>  
> -	if (!dwc->sysdev_is_parent &&
> +	if (!dev_is_pci(dwc->sysdev) &&
>  	    DWC3_GHWPARAMS0_AWIDTH(dwc->hwparams.hwparams0) == 64) {
>  		ret = dma_set_mask_and_coherent(dwc->sysdev, DMA_BIT_MASK(64));
>  		if (ret)
> -- 
> 2.34.1
> 

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

BR,
Thinh