From fb16a3835107c469433a71341d198c298449ff4d Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 4 Sep 2018 17:58:54 +0200 Subject: [PATCH] staging: bcm2835-audio: Use coherent device buffers The memory access to the pages allocated with SNDRV_DMA_TYPE_CONTINUOUS are basically non-coherent, and it becomes a problem when a process accesses via mmap. For the more consistent access, use the device coherent memory, just by replacing the call pattern in the allocator helpers. The only point we need to be careful for is the device object passed there; since bcm2835-audio driver creates fake devices and each card is created on top of that, we need to pass its parent device as the real device object. Signed-off-by: Takashi Iwai Tested-by: Stefan Wahren Signed-off-by: Greg Kroah-Hartman --- .../vc04_services/bcm2835-audio/bcm2835-pcm.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c index d2373e4a4d53..8b8e286587cb 100644 --- a/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c +++ b/drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c @@ -345,8 +345,8 @@ int snd_bcm2835_new_pcm(struct bcm2835_chip *chip, u32 numchannels) /* pre-allocation of buffers */ /* NOTE: this may fail */ - snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS, - snd_dma_continuous_data(GFP_KERNEL), + snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV, + chip->card->dev->parent, snd_bcm2835_playback_hw.buffer_bytes_max, snd_bcm2835_playback_hw.buffer_bytes_max); @@ -371,8 +371,8 @@ int snd_bcm2835_new_spdif_pcm(struct bcm2835_chip *chip) /* pre-allocation of buffers */ /* NOTE: this may fail */ - snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_CONTINUOUS, - snd_dma_continuous_data(GFP_KERNEL), + snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV, + chip->card->dev->parent, snd_bcm2835_playback_spdif_hw.buffer_bytes_max, snd_bcm2835_playback_spdif_hw.buffer_bytes_max); return 0; @@ -404,8 +404,8 @@ int snd_bcm2835_new_simple_pcm(struct bcm2835_chip *chip, snd_pcm_lib_preallocate_pages_for_all( pcm, - SNDRV_DMA_TYPE_CONTINUOUS, - snd_dma_continuous_data(GFP_KERNEL), + SNDRV_DMA_TYPE_DEV, + chip->card->dev->parent, snd_bcm2835_playback_hw.buffer_bytes_max, snd_bcm2835_playback_hw.buffer_bytes_max); -- 2.30.2