Hi Greg, > -----Original Message----- > From: Greg KH <[email protected]> > Sent: 2020年9月25日 20:17 > To: Sherry Sun <[email protected]> > Cc: [email protected]; [email protected]; [email protected]; > [email protected]; [email protected]; > [email protected]; [email protected]; [email protected]; linux- > [email protected]; dl-linux-imx <[email protected]> > Subject: Re: [PATCH 4/5] misc: vop: set VIRTIO_F_ACCESS_PLATFORM for > nocoherent platform > > On Fri, Sep 25, 2020 at 03:26:29PM +0800, Sherry Sun wrote: > > Set VIRTIO_F_ACCESS_PLATFORM feature for nocoherent platform, since it > > needs the DMA API for virtio. > > > > Signed-off-by: Sherry Sun <[email protected]> > > Signed-off-by: Joakim Zhang <[email protected]> > > --- > > drivers/misc/mic/vop/vop_main.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/drivers/misc/mic/vop/vop_main.c > > b/drivers/misc/mic/vop/vop_main.c index d3645122c983..d609f0dc6124 > > 100644 > > --- a/drivers/misc/mic/vop/vop_main.c > > +++ b/drivers/misc/mic/vop/vop_main.c > > @@ -125,6 +125,9 @@ static void vop_transport_features(struct > virtio_device *vdev) > > * creates virtio rings on preallocated memory. > > */ > > __virtio_clear_bit(vdev, VIRTIO_F_RING_PACKED); > > + > > + if (!dev_is_dma_coherent(vdev->dev.parent)) > > + __virtio_set_bit(vdev, VIRTIO_F_ACCESS_PLATFORM); > > Why look at the parent and not the device itself?
That's a good question, here use vdev->dev.parent to get the vop device instead of virtio device, which can keep consistent with other dev_is_dma_coherent check. Thanks Sherry
