Re: [PATCH] dmaengine: axi-dmac: simple device_config operation implemented

From: Vinod Koul <vkoul@kernel.org>
To: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
	lars@metafoo.de, Rodrigo Alencar <alencar.fmce@imbel.gov.br>
Subject: Re: [PATCH] dmaengine: axi-dmac: simple device_config operation implemented
Date: Mon, 14 Oct 2019 12:31:42 +0530	[thread overview]
Message-ID: <20191014070142.GB2654@vkoul-mobl> (raw)
In-Reply-To: <20190913145404.28715-1-alexandru.ardelean@analog.com>

On 13-09-19, 17:54, Alexandru Ardelean wrote:
> From: Rodrigo Alencar <alencar.fmce@imbel.gov.br>
> 
> dmaengine_slave_config is called by dmaengine_pcm_hw_params when using
> axi-i2s with axi-dmac. If device_config is NULL, -ENOSYS  is returned,
> which breaks the snd_pcm_hw_params function.
> This is a fix for the error:

and what is that?

> 
> $ aplay -D plughw:ADAU1761 /usr/share/sounds/alsa/Front_Center.wav
> Playing WAVE '/usr/share/sounds/alsa/Front_Center.wav' : Signed 16 bit
> Little Endian, Rate 48000 Hz, Mono
> axi-i2s 43c20000.axi-i2s: ASoC: 43c20000.axi-i2s hw params failed: -38
> aplay: set_params:1403: Unable to install hw params:
> ACCESS:  RW_INTERLEAVED
> FORMAT:  S16_LE
> SUBFORMAT:  STD
> SAMPLE_BITS: 16
> FRAME_BITS: 16
> CHANNELS: 1
> RATE: 48000
> PERIOD_TIME: 125000
> PERIOD_SIZE: 6000
> PERIOD_BYTES: 12000
> PERIODS: 4
> BUFFER_TIME: 500000
> BUFFER_SIZE: 24000
> BUFFER_BYTES: 48000
> TICK_TIME: 0
> 
> Signed-off-by: Rodrigo Alencar <alencar.fmce@imbel.gov.br>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> ---
> 
> Note: Fixes tag not added intentionally.
> 
>  drivers/dma/dma-axi-dmac.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/dma/dma-axi-dmac.c b/drivers/dma/dma-axi-dmac.c
> index a0ee404b736e..ab2677343202 100644
> --- a/drivers/dma/dma-axi-dmac.c
> +++ b/drivers/dma/dma-axi-dmac.c
> @@ -564,6 +564,21 @@ static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg(
>  	return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
>  }
>  
> +static int axi_dmac_device_config(struct dma_chan *c,
> +			struct dma_slave_config *slave_config)
> +{
> +	struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
> +	struct axi_dmac *dmac = chan_to_axi_dmac(chan);
> +
> +	/* no configuration required, a sanity check is done instead */
> +	if (slave_config->direction != chan->direction) {

 slave_config->direction is a deprecated field, pls dont use that

> +		dev_err(dmac->dma_dev.dev, "Direction not supported by this DMA Channel");
> +		return -EINVAL;

So you intent to support slave dma but do not use dma_slave_config.. how
are you getting the slave address and other details?

Thanks
-- 
~Vinod