• Kuninori Morimoto's avatar
    ASoC: rsnd: Enable IPMMU v2 · 5423d772
    Kuninori Morimoto authored
    commit 4821d914 ("ASoC: rsnd: use dma_sync_single_for_xxx() for
    IOMMU") (= v1) which have been already reverted had supported IPMMU
    support on rsnd driver.
    Because memory allocating timing and DMAEngine access timing were
    different, it used continuous memory and called dma map function by
    itself.
    
    OTOH, it is using DMA descriptor mode (= DMA cyclic mode), thus, there
    was timing conflict between DMA sync/unsync and DMA transfer starting,
    and it maked sound noise.
    
    This patch supports IPMMU with coherent memory, and, it uses Audio DMAC
    dev for allocating memory by snd_pcm_lib_preallocate_pages_for_all() to
    indicate memory area to IPMMU.
    One note is that Playback/Capture need each paired Audio DMAC dev.
    Because of this, we need to keep each paired Audio DMAC dev when probing,
    and use it when allocating each memory for IPMMU.
    Signed-off-by: default avatarKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
    Tested-by: default avatarHiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
    Signed-off-by: default avatarMark Brown <broonie@kernel.org>
    5423d772
dma.c 19.6 KB