Messages in this thread | ![/](/images/icornerl.gif) | | From | Heiko Stuebner <> | Subject | Re: [PATCH v2] arm64: dts: rockchip: enable HDMI sound nodes for rk3328-rock64 | Date | Sun, 30 Aug 2020 21:16:47 +0200 |
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Hi,
Am Sonntag, 2. August 2020, 17:42:31 CEST schrieb Katsuhiro Suzuki: > This patch enables HDMI sound (I2S0) and Analog sound (I2S1) which > are defined in rk3328.dtsi, and replace SPDIF nodes. > > We can use SPDIF pass-through with suitable ALSA settings and on > mpv or other media players. > - Settings: https://github.com/LibreELEC/LibreELEC.tv/blob/master/projects/Rockchip/filesystem/usr/share/alsa/cards/SPDIF.conf > - Ex.: mpv foo.ac3 --audio-spdif=ac3 --audio-device='alsa/SPDIF.pcm.iec958.0:SPDIF' > > [Why use simple-audio-card for SPDIF?] > > For newly adding nodes, ASoC guys recommend to use audio-graph-card. > But all other sound nodes for rk3328 have already been defined by > simple-audio-card. In this time, I chose for consistent sound nodes. > > [DMA allocation problem] > > After this patch is applied, UART2 will fail to allocate DMA resources > but UART driver can work fine without DMA. > > This error is related to the DMAC of rk3328 (pl330 or compatible). > DMAC connected to 16 DMA sources. Each sources have ID number that is > called 'Req number' in rk3328 TRM. After this patch is applied total 7 > of DMA sources will be activated as follows: > > | Req number | Source | Required | > | | | channels | > |------------+--------+-----------| > | 8, 9 | SPI0 | 2ch | > | 11, 12 | I2S0 | 2ch | > | 14, 15 | I2S1 | 2ch | > | 10 | SPDIF | 1ch | > |------------+--------+-----------| > | | Total | 7ch | > |------------+--------+-----------| > | 6, 7 | UART2 | 2ch | -> cannot get DMA channels > > Due to rk3328 DMAC specification we can use max 8 channels at same > time. If SPI0/I2S0/I2S1/SPDIF will be activated by this patch, > required DMAC channels reach to 7. So the last two channels (for > UART2) cannot get DMA resources.
Wouldn't the dma allocation depend on the probe ordering? Or is this predetermined, so that always uart2 looses its dmas?
Heiko
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