This driver requires imported PRIME buffers to appear contiguously in
its IO address space. Make sure this is the case by setting the maximum
DMA segment size to a better value than the default 64K on the DMA
device, and use said DMA device when importing PRIME buffers.
Signed-off-by: Alexandre Courbot <acour...@chromium.org>
---
drivers/gpu/drm/mediatek/mtk_drm_drv.c | 47 ++++++++++++++++++++++++--
drivers/gpu/drm/mediatek/mtk_drm_drv.h | 2 ++
2 files changed, 46 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 95fdbd0fbcac..4ad4770fab13 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -213,6 +213,7 @@ static int mtk_drm_kms_init(struct drm_device *drm)
struct mtk_drm_private *private = drm->dev_private;
struct platform_device *pdev;
struct device_node *np;
+ struct device *dma_dev;
int ret;
if (!iommu_present(&platform_bus_type))
@@ -275,7 +276,27 @@ static int mtk_drm_kms_init(struct drm_device *drm)
goto err_component_unbind;
}
- private->dma_dev = &pdev->dev;
+ dma_dev = &pdev->dev;
+ private->dma_dev = dma_dev;
+
+ /*
+ * Configure the DMA segment size to make sure we get contiguous IOVA
+ * when importing PRIME buffers.
+ */
+ if (!dma_dev->dma_parms) {
+ private->dma_parms_allocated = true;
+ dma_dev->dma_parms =
+ devm_kzalloc(drm->dev, sizeof(*dma_dev->dma_parms),
+ GFP_KERNEL);
+ }
+ if (!dma_dev->dma_parms)
+ goto err_component_unbind;
+
+ ret = dma_set_max_seg_size(dma_dev, (unsigned int)DMA_BIT_MASK(32));
+ if (ret) {
+ dev_err(dma_dev, "Failed to set DMA segment size\n");
+ goto err_unset_dma_parms;
+ }
/*
* We don't use the drm_irq_install() helpers provided by the DRM
@@ -285,13 +306,16 @@ static int mtk_drm_kms_init(struct drm_device *drm)
drm->irq_enabled = true;
ret = drm_vblank_init(drm, MAX_CRTC);
if (ret < 0)
- goto err_component_unbind;
+ goto err_unset_dma_parms;
drm_kms_helper_poll_init(drm);
drm_mode_config_reset(drm);
return 0;
+err_unset_dma_parms:
+ if (private->dma_parms_allocated)
+ dma_dev->dma_parms = NULL;
err_component_unbind:
component_unbind_all(drm->dev, drm);
err_config_cleanup:
@@ -302,9 +326,14 @@ static int mtk_drm_kms_init(struct drm_device *drm)
static void mtk_drm_kms_deinit(struct drm_device *drm)
{
+ struct mtk_drm_private *private = drm->dev_private;
+
drm_kms_helper_poll_fini(drm);
drm_atomic_helper_shutdown(drm);
+ if (private->dma_parms_allocated)
+ private->dma_dev->dma_parms = NULL;
+
component_unbind_all(drm->dev, drm);
drm_mode_config_cleanup(drm);
}
@@ -320,6 +349,18 @@ static const struct file_operations mtk_drm_fops = {
.compat_ioctl = drm_compat_ioctl,
};
+/*
+ * We need to override this because the device used to import the memory is
+ * not dev->dev, as drm_gem_prime_import() expects.
+ */
+struct drm_gem_object *mtk_drm_gem_prime_import(struct drm_device *dev,
+ struct dma_buf *dma_buf)
+{
+ struct mtk_drm_private *private = dev->dev_private;
+
+ return drm_gem_prime_import_dev(dev, dma_buf, private->dma_dev);
+}
+
static struct drm_driver mtk_drm_driver = {
.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME |
DRIVER_ATOMIC,
@@ -331,7 +372,7 @@ static struct drm_driver mtk_drm_driver = {
.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
.gem_prime_export = drm_gem_prime_export,
- .gem_prime_import = drm_gem_prime_import,
+ .gem_prime_import = mtk_drm_gem_prime_import,
.gem_prime_get_sg_table = mtk_gem_prime_get_sg_table,
.gem_prime_import_sg_table = mtk_gem_prime_import_sg_table,
.gem_prime_mmap = mtk_drm_gem_mmap_buf,
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
index 598ff3e70446..e03fea12ff59 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
@@ -51,6 +51,8 @@ struct mtk_drm_private {
} commit;
struct drm_atomic_state *suspend_state;
+
+ bool dma_parms_allocated;
};
extern struct platform_driver mtk_ddp_driver;
--
2.22.0.657.g960e92d24f-goog
