[alsa-devel] [PATCH 2/4] ALSA: x86: Explicit specify 32bit DMA

[Takashi Iwai]

LPE audio is capable only up to 32bit address, as it seems.
Then we should limit the DMA addresses accordingly via dma-mapping
API.

Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 sound/x86/intel_hdmi_audio.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sound/x86/intel_hdmi_audio.c b/sound/x86/intel_hdmi_audio.c
index 32a21422e6f5..9e08132fd332 100644
--- a/sound/x86/intel_hdmi_audio.c
+++ b/sound/x86/intel_hdmi_audio.c
@@ -28,6 +28,7 @@
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/pm_runtime.h>
+#include <linux/dma-mapping.h>
 #include <asm/cacheflush.h>
 #include <sound/core.h>
 #include <sound/asoundef.h>
@@ -1823,8 +1824,6 @@ static int hdmi_lpe_audio_probe(struct platform_device *pdev)
 	struct resource *res_mmio;
 	int i, ret;
 
-	dev_dbg(&pdev->dev, "dma_mask: %p\n", pdev->dev.dma_mask);
-
 	pdata = pdev->dev.platform_data;
 	if (!pdata) {
 		dev_err(&pdev->dev, "%s: quit: pdata not allocated by i915!!\n", __func__);
@@ -1905,6 +1904,11 @@ static int hdmi_lpe_audio_probe(struct platform_device *pdev)
 	/* setup the ops for playabck */
 	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK,
 			    &snd_intelhad_playback_ops);
+
+	/* only 32bit addressable */
+	dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
+	dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
+
 	/* allocate dma pages for ALSA stream operations
 	 * memory allocated is based on size, not max value
 	 * thus using same argument for max & size
-- 
2.11.0