Re: [PATCH] usb: cdns3: Fix for incorrect DMA mask.

[Peter Chen]

On 19-10-07 13:03:23, Pawel Laszczak wrote:
> This patch restores the correct DMA mask after switching back to device
> mode.
> The issue occurred because Device part of controller use 32 bits DMA and
> Host side use 64 bits DMA. During loading XHCI driver the DMA mask
> used by driver is overwritten by XHCI driver so it must be restored
> to 32 bits.
> 
> Reported-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> Signed-off-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
> Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
> ---
>  drivers/usb/cdns3/gadget.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c
> index 157536753b8c..2ca280f4c054 100644
> --- a/drivers/usb/cdns3/gadget.c
> +++ b/drivers/usb/cdns3/gadget.c
> @@ -2663,6 +2663,13 @@ static int __cdns3_gadget_init(struct cdns3 *cdns)
>  {
>  	int ret = 0;
>  
> +	/* Ensure 32-bit DMA Mask in case we switched back from Host mode */
> +	ret = dma_set_mask_and_coherent(cdns->dev, DMA_BIT_MASK(32));
> +	if (ret) {
> +		dev_err(cdns->dev, "Failed to set dma mask: %d\n", ret);
> +		return ret;
> +	}
> +
>  	cdns3_drd_switch_gadget(cdns, 1);
>  	pm_runtime_get_sync(cdns->dev);
>  

Reviewed-by: Peter Chen <peter.chen@xxxxxxx>

-- 

Thanks,
Peter Chen