Message-ID: <029e4c99-3aa5-fdb8-6ddc-fd3b144e4253@redhat.com>
Date:   Sun, 14 Nov 2021 21:58:14 +0100
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Subject: Re: [PATCH] usb: dwc3: leave default DMA for PCI devices
Content-Language: en-US
To:     Fabio Aiuto <fabioaiuto83@gmail.com>, gregkh@linuxfoundation.org
Cc:     balbi@kernel.org, arnd@arndb.de, hch@lst.de, sven@svenpeter.dev,
        linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20211113142959.27191-1-fabioaiuto83@gmail.com>
From:   Hans de Goede <hdegoede@redhat.com>
In-Reply-To: <20211113142959.27191-1-fabioaiuto83@gmail.com>
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Precedence: bulk

Hi,

On 11/13/21 15:29, Fabio Aiuto wrote:
> in case of a PCI dwc3 controller, leave the default DMA
> mask. Calling of a 64 bit DMA mask breaks the driver on
> cherrytrail based tablets like Cyberbook T116.
> 
> Fixes: 45d39448b4d0 ("usb: dwc3: support 64 bit DMA in platform driver")
> Reported-by: Hans De Goede <hdegoede@redhat.com>
> Tested-by: Fabio Aiuto <fabioaiuto83@gmail.com>
> Signed-off-by: Fabio Aiuto <fabioaiuto83@gmail.com>

I can confirm that this fixes things for me to:

Tested-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans


> ---
>  drivers/usb/dwc3/core.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 643239d7d370..f4c09951b517 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1594,9 +1594,11 @@ static int dwc3_probe(struct platform_device *pdev)
>  
>  	dwc3_get_properties(dwc);
>  
> -	ret = dma_set_mask_and_coherent(dwc->sysdev, DMA_BIT_MASK(64));
> -	if (ret)
> -		return ret;
> +	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))
>