Commit 9df6861a authored Dec 04, 2018 by Yu Zhao Committed by Greg Kroah-Hartman Jan 26, 2019

ASoC: use dma_ops of parent device for acp_audio_dma



[ Upstream commit 23aa128bb28d9da69bb1bdb2b70e50128857884a ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 597a09e0

sound/soc/amd/acp-pcm-dma.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -1147,18 +1147,21 @@ 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;
		}