On Tue, Feb 23, 2016 at 03:25:53PM +0900, Alexandre Courbot wrote: > The current settings leaves the DRM device's dma_ops field NULL, which > makes it use the dummy DMA ops on arm64 and return an error whenever we > try to import a buffer. Call of_dma_configure() with a NULL node (since > the device is not spawn from the device tree) so that > arch_setup_dma_ops() is called and sets the default ioswtlb DMA ops. > > Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx> > --- > drivers/gpu/drm/tegra/drm.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c > index d347188bf8f4..bc0555adecaf 100644 > --- a/drivers/gpu/drm/tegra/drm.c > +++ b/drivers/gpu/drm/tegra/drm.c > @@ -9,6 +9,7 @@ > > #include <linux/host1x.h> > #include <linux/iommu.h> > +#include <linux/of_device.h> > > #include <drm/drm_atomic.h> > #include <drm/drm_atomic_helper.h> > @@ -990,6 +991,7 @@ static int host1x_drm_probe(struct host1x_device *dev) > return -ENOMEM; > > dev_set_drvdata(&dev->dev, drm); > + of_dma_configure(drm->dev, NULL); Looking at the various pieces, I think this really belongs in host1x_device_add() (see drivers/gpu/host1x/bus.c) where it can replace the open-coded setting of DMA and coherent DMA masks. Also why can't we pass the correct device tree node here? The DRM device is a virtual device that hangs off the host1x device, so I think it could use the same device tree node as the host1x device. Something like the below (untested). Thierry --- >8 --- diff --git a/drivers/gpu/host1x/bus.c b/drivers/gpu/host1x/bus.c index c2e7fba370bb..d46d26a574da 100644 --- a/drivers/gpu/host1x/bus.c +++ b/drivers/gpu/host1x/bus.c @@ -17,6 +17,7 @@ #include <linux/host1x.h> #include <linux/of.h> +#include <linux/of_device.h> #include <linux/slab.h> #include "bus.h" @@ -393,9 +394,8 @@ static int host1x_device_add(struct host1x *host1x, INIT_LIST_HEAD(&device->list); device->driver = driver; - device->dev.coherent_dma_mask = host1x->dev->coherent_dma_mask; - device->dev.dma_mask = &device->dev.coherent_dma_mask; dev_set_name(&device->dev, "%s", driver->driver.name); + of_dma_configure(&device->dev, host1x->dev->of_node); device->dev.release = host1x_device_release; device->dev.bus = &host1x_bus_type; device->dev.parent = host1x->dev;
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