ASoC: use dma_ops of parent device for acp_audio_dma

AMD platform device acp_audio_dma can only be created by parent PCI
device driver (drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c). Pass struct
device of the parent to snd_pcm_lib_preallocate_pages() so
dma_alloc_coherent() can use correct dma_ops. Otherwise, it will
use default dma_ops which is nommu_dma_ops on x86_64 even when
IOMMU is enabled and set to non passthrough mode.

Though platform device inherits some dma related fields during its
creation in mfd_add_device(), we can't simply pass its struct device
to snd_pcm_lib_preallocate_pages() because dma_ops is not among the
inherited fields. Even it were, drivers/iommu/amd_iommu.c would
ignore it because get_device_id() doesn't handle platform device.

This change shouldn't give us any trouble even struct device of the
parent becomes null or represents some non PCI device in the future,
because get_dma_ops() correctly handles null struct device or uses
the default dma_ops if struct device doesn't have it set.

Signed-off-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c
index fd3db4c3788299cfab9ff3616cd6c77e98c4f734..f4011bebc7ec0fec945464ad62f9986b76256e87 100644 (file)
--- a/sound/soc/amd/acp-pcm-dma.c
+++ b/sound/soc/amd/acp-pcm-dma.c
@@ -1146,18 +1146,21 @@ static int acp_dma_new(struct snd_soc_pcm_runtime *rtd)
        struct snd_soc_component *component = snd_soc_rtdcom_lookup(rtd,
                                                                    DRV_NAME);
        struct audio_drv_data *adata = dev_get_drvdata(component->dev);
+       struct device *parent = component->dev->parent;
 
        switch (adata->asic_type) {
        case CHIP_STONEY:
                ret = snd_pcm_lib_preallocate_pages_for_all(rtd->pcm,
                                                            SNDRV_DMA_TYPE_DEV,
-                                                           NULL, ST_MIN_BUFFER,
+                                                           parent,
+                                                           ST_MIN_BUFFER,
                                                            ST_MAX_BUFFER);
                break;
        default:
                ret = snd_pcm_lib_preallocate_pages_for_all(rtd->pcm,
                                                            SNDRV_DMA_TYPE_DEV,
-                                                           NULL, MIN_BUFFER,
+                                                           parent,
+                                                           MIN_BUFFER,
                                                            MAX_BUFFER);
                break;
        }