Re: [PATCH v2 08/14] ASoC: amd: add ACP PDM DMA driver dai ops

[Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>]

> +static int start_pdm_dma(void __iomem *acp_base)
> +{
> +	u32 pdm_enable;
> +	u32 pdm_dma_enable;
> +	int timeout;
> +
> +	pdm_enable = 0x01;
> +	pdm_dma_enable  = 0x01;
> +
> +	enable_pdm_clock(acp_base);
> +	rn_writel(pdm_enable, acp_base + ACP_WOV_PDM_ENABLE);
> +	rn_writel(pdm_dma_enable, acp_base + ACP_WOV_PDM_DMA_ENABLE);
> +	pdm_dma_enable = 0x00;
> +	timeout = 0;
> +	while (++timeout < ACP_COUNTER) {
> +		pdm_dma_enable = rn_readl(acp_base + ACP_WOV_PDM_DMA_ENABLE);
> +		if ((pdm_dma_enable & 0x02) == ACP_PDM_DMA_EN_STATUS)
> +			return 0;
> +		udelay(DELAY_US);
> +	}
> +	return -ETIMEDOUT;
> +}
> +
> +static int stop_pdm_dma(void __iomem *acp_base)
> +{
> +	u32 pdm_enable, pdm_dma_enable, pdm_fifo_flush;
> +	int timeout;
> +
> +	pdm_enable = 0x00;
> +	pdm_dma_enable  = 0x00;
> +	pdm_fifo_flush = 0x00;
> +
> +	pdm_enable = rn_readl(acp_base + ACP_WOV_PDM_ENABLE);
> +	pdm_dma_enable = rn_readl(acp_base + ACP_WOV_PDM_DMA_ENABLE);
> +	if (pdm_dma_enable & 0x01) {
> +		pdm_dma_enable = 0x02;
> +		rn_writel(pdm_dma_enable, acp_base + ACP_WOV_PDM_DMA_ENABLE);
> +		pdm_dma_enable = 0x00;
> +		timeout = 0;
> +		while (++timeout < ACP_COUNTER) {
> +			pdm_dma_enable = rn_readl(acp_base +
> +						  ACP_WOV_PDM_DMA_ENABLE);
> +			if ((pdm_dma_enable & 0x02) == 0x00)
> +				break;
> +			udelay(DELAY_US);
> +		}
> +		if (timeout == ACP_COUNTER)

if you reach this point, timeout is by construction equal to ACP_COUNTER 
so this test is useless

You could also use a helper where you check if the value is 
ACP_PDM_DMA_EN_STATUS or zero so that you don't copy the same logic twice.