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

[Punit Agrawal <punit.agrawal@oss.qualcomm.com>]

Thinh Nguyen <Thinh.Nguyen@synopsys.com> writes:

> 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>

Thank you for taking a look.

Not sure if Greg prefers a repost or he can add the tag and Cc: stable
while applying. I'll resend next week with updates if there's no
response.

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