Re: [alsa-devel] [PATCH 1/8] drm/amd/amdgpu: Added asic_type as ACP DMA driver platform data

On Fri, Jun 23, 2017 at 12:43 PM, Christian König deathsimple@vodafone.de wrote:

Am 23.06.2017 um 18:34 schrieb Alex Deucher:

...

From: Vijendar Mukunda Vijendar.Mukunda@amd.com

asic_type information is passed to ACP DMA Driver as platform data. We need this to determine whether the asic is Carrizo (CZ) or Stoney (ST) in the acp sound driver.

Reviewed-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Vijendar Mukunda Vijendar.Mukunda@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com

---

drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c | 4 ++++ sound/soc/amd/acp-pcm-dma.c | 8 ++------ sound/soc/amd/acp.h | 7 +++++++ 3 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c index 06879d1..7a2a765 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acp.c @@ -262,6 +262,7 @@ static int acp_hw_init(void *handle) uint64_t acp_base; struct device *dev; struct i2s_platform_data *i2s_pdata;

•   u32 asic_type;
    struct amdgpu_device *adev = (struct amdgpu_device *)handle;
  

  @@ -271,6 +272,7 @@ static int acp_hw_init(void *handle) if (!ip_block) return -EINVAL;

  • asic_type = adev->asic_type;
    r = amd_acp_hw_init(adev->acp.cgs_device,
                        ip_block->version->major,
    

ip_block->version->minor); /* -ENODEV means board uses AZ rather than ACP */ @@ -355,6 +357,8 @@ static int acp_hw_init(void *handle) adev->acp.acp_cell[0].name = "acp_audio_dma"; adev->acp.acp_cell[0].num_resources = 4; adev->acp.acp_cell[0].resources = &adev->acp.acp_res[0];

•   adev->acp.acp_cell[0].platform_data = &asic_type;
  

•   adev->acp.acp_cell[0].pdata_size = sizeof(asic_type);
  

Have the painkillers jellyfied my brain or are you setting a pointer in the amdgpu device structure to some variable on the stack?

If it's just for initialization then that's probably ok, but I would reset the pointer at the end of the function.

Otherwise somebody might have the idea to dereference it later on and that can only lead to trouble.

I think it's ok because the hotplug of the audio device is triggered from this function, so the audio device should be probed by the time this variable goes out of scope. That said, it would probably be better to use the asic_type from the GPU driver instance directly rather than a stack variable.

Alex

Christian.

...

    adev->acp.acp_cell[1].name = "designware-i2s";
    adev->acp.acp_cell[1].num_resources = 1;

diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c index 08b1399..dcbf997 100644 --- a/sound/soc/amd/acp-pcm-dma.c +++ b/sound/soc/amd/acp-pcm-dma.c @@ -73,12 +73,6 @@ static const struct snd_pcm_hardware acp_pcm_hardware_capture = { .periods_max = CAPTURE_MAX_NUM_PERIODS, }; -struct audio_drv_data {

•   struct snd_pcm_substream *play_stream;
  

•   struct snd_pcm_substream *capture_stream;
  

•   void __iomem *acp_mmio;
  

-};

• static u32 acp_reg_read(void __iomem *acp_mmio, u32 reg) { return readl(acp_mmio + (reg * 4));

@@ -916,6 +910,7 @@ static int acp_audio_probe(struct platform_device *pdev) int status; struct audio_drv_data *audio_drv_data; struct resource *res;

•   const u32 *pdata = pdev->dev.platform_data;
    audio_drv_data = devm_kzalloc(&pdev->dev, sizeof(struct
  

audio_drv_data), GFP_KERNEL); @@ -932,6 +927,7 @@ static int acp_audio_probe(struct platform_device *pdev) audio_drv_data->play_stream = NULL; audio_drv_data->capture_stream = NULL;

•   audio_drv_data->asic_type =  *pdata;
    res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
    if (!res) {
  

diff --git a/sound/soc/amd/acp.h b/sound/soc/amd/acp.h index 330832e..28cf914 100644 --- a/sound/soc/amd/acp.h +++ b/sound/soc/amd/acp.h @@ -84,6 +84,13 @@ struct audio_substream_data { void __iomem *acp_mmio; }; +struct audio_drv_data {

•   struct snd_pcm_substream *play_stream;
  

•   struct snd_pcm_substream *capture_stream;
  

•   void __iomem *acp_mmio;
  

•   u32 asic_type;
  

+};

• enum { ACP_TILE_P1 = 0, ACP_TILE_P2,