Re: [PATCH V2 2/9] ASoC: amd: ps: handle SoundWire interrupts in acp pci driver

Pierre-Louis Bossart
2023-05-22T18:32:14Z

On 5/22/23 08:31, Vijendar Mukunda wrote:
> Handle SoundWire manager related interrupts in ACP PCI driver
> interrupt handler and schedule SoundWire manager work queue for
> further processing.
>
> Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
> ---
> sound/soc/amd/ps/acp63.h | 4 ++++
> sound/soc/amd/ps/pci-ps.c | 43 ++++++++++++++++++++++++++++++++++-----
> 2 files changed, 42 insertions(+), 5 deletions(-)
>
> diff --git a/sound/soc/amd/ps/acp63.h b/sound/soc/amd/ps/acp63.h
> index 95bb1cef900a..d296059be4f0 100644
> --- a/sound/soc/amd/ps/acp63.h
> +++ b/sound/soc/amd/ps/acp63.h
> @@ -88,6 +88,10 @@
> /* time in ms for acp timeout */
> #define ACP_TIMEOUT 500
>
> +#define ACP_SDW0_STAT BIT(21)
> +#define ACP_SDW1_STAT BIT(2)
> +#define ACP_ERROR_IRQ BIT(29)
> +
> enum acp_config {
> ACP_CONFIG_0 = 0,
> ACP_CONFIG_1,
> diff --git a/sound/soc/amd/ps/pci-ps.c b/sound/soc/amd/ps/pci-ps.c
> index 02caae6968ad..26514e340a33 100644
> --- a/sound/soc/amd/ps/pci-ps.c
> +++ b/sound/soc/amd/ps/pci-ps.c
> @@ -56,6 +56,7 @@ static int acp63_reset(void __iomem *acp_base)
> static void acp63_enable_interrupts(void __iomem *acp_base)
> {
> writel(1, acp_base + ACP_EXTERNAL_INTR_ENB);
> + writel(ACP_ERROR_IRQ, acp_base + ACP_EXTERNAL_INTR_CNTL);

you may want to comment on why you don't have a read-modify-write
approach for something that looks generic and not limited to a single
error bit?

> }
>
> static void acp63_disable_interrupts(void __iomem *acp_base)
> @@ -102,23 +103,55 @@ static irqreturn_t acp63_irq_handler(int irq, void *dev_id)
> {
> struct acp63_dev_data *adata;
> struct pdm_dev_data *ps_pdm_data;
> - u32 val;
> + struct amd_sdw_manager *amd_manager;
> + u32 ext_intr_stat, ext_intr_stat1;
> + u16 irq_flag = 0;
> u16 pdev_index;
>
> adata = dev_id;
> if (!adata)
> return IRQ_NONE;
> + ext_intr_stat = readl(adata->acp63_base + ACP_EXTERNAL_INTR_STAT);
> + if (ext_intr_stat & ACP_SDW0_STAT) {
> + writel(ACP_SDW0_STAT, adata->acp63_base + ACP_EXTERNAL_INTR_STAT);

[1]

this is confusing, if this is w1c, should this be:

writel(ext_intr_stat, adata->acp63_base + ACP_EXTERNAL_INTR_STAT);

Otherwise you may be clearing fields that have not been set?

> + pdev_index = adata->sdw0_dev_index;
> + amd_manager = dev_get_drvdata(&adata->pdev[pdev_index]->dev);
> + if (amd_manager)
> + schedule_work(&amd_manager->amd_sdw_irq_thread);
> + irq_flag = 1;
> + }
>
> - val = readl(adata->acp63_base + ACP_EXTERNAL_INTR_STAT);
> - if (val & BIT(PDM_DMA_STAT)) {
> + ext_intr_stat1 = readl(adata->acp63_base + ACP_EXTERNAL_INTR_STAT1);
> + if (ext_intr_stat1 & ACP_SDW1_STAT) {
> + writel(ACP_SDW1_STAT, adata->acp63_base + ACP_EXTERNAL_INTR_STAT1);

same comment here.

> + pdev_index = adata->sdw1_dev_index;
> + amd_manager = dev_get_drvdata(&adata->pdev[pdev_index]->dev);
> + if (amd_manager)
> + schedule_work(&amd_manager->amd_sdw_irq_thread);
> + irq_flag = 1;
> + }
> +
> + if (ext_intr_stat & ACP_ERROR_IRQ) {
> + writel(ACP_ERROR_IRQ, adata->acp63_base + ACP_EXTERNAL_INTR_STAT);

[2]

and this is even move confusing because you may end-up writing twice to
the same adata->acp63_base + ACP_EXTERNAL_INTR_STAT with [1] and [2], so
the previous write

writel(ACP_SDW0_STAT, adata->acp63_base + ACP_EXTERNAL_INTR_STAT);

may have cleared the register already.

Something looks wrong here?

> + /* TODO: Report SoundWire Manager instance errors */
> + writel(0, adata->acp63_base + ACP_SW0_I2S_ERROR_REASON);
> + writel(0, adata->acp63_base + ACP_SW1_I2S_ERROR_REASON);
> + writel(0, adata->acp63_base + ACP_ERROR_STATUS);
> + irq_flag = 1;
> + }
> +
> + if (ext_intr_stat & BIT(PDM_DMA_STAT)) {
> pdev_index = adata->pdm_dev_index;
> ps_pdm_data = dev_get_drvdata(&adata->pdev[pdev_index]->dev);
> writel(BIT(PDM_DMA_STAT), adata->acp63_base + ACP_EXTERNAL_INTR_STAT);
> if (ps_pdm_data->capture_stream)
> snd_pcm_period_elapsed(ps_pdm_data->capture_stream);
> - return IRQ_HANDLED;
> + irq_flag = 1;
> }
> - return IRQ_NONE;
> + if (irq_flag)
> + return IRQ_HANDLED;
> + else
> + return IRQ_NONE;
> }
>
> static int sdw_amd_scan_controller(struct device *dev)