[V6,5/8] soundwire: amd: add SoundWire manager interrupt handling

Message ID 20230307133135.545952-6-Vijendar.Mukunda@amd.com
State New
Headers
Series [V6,1/8] soundwire: export sdw_compute_slave_ports() function |

Commit Message

Mukunda,Vijendar March 7, 2023, 1:31 p.m. UTC
  Add support for handling SoundWire manager interrupts.

Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
Signed-off-by: Mastan Katragadda <Mastan.Katragadda@amd.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/lkml/20230227154801.50319-6-Vijendar.Mukunda@amd.com
---
 drivers/soundwire/amd_manager.c   | 130 ++++++++++++++++++++++++++++++
 drivers/soundwire/amd_manager.h   |   1 +
 include/linux/soundwire/sdw_amd.h |   7 ++
 3 files changed, 138 insertions(+)
  

Comments

Vinod Koul March 15, 2023, 10:06 a.m. UTC | #1
On 07-03-23, 19:01, Vijendar Mukunda wrote:
> Add support for handling SoundWire manager interrupts.
> 
> Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
> Signed-off-by: Mastan Katragadda <Mastan.Katragadda@amd.com>
> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
> Link: https://lore.kernel.org/lkml/20230227154801.50319-6-Vijendar.Mukunda@amd.com
> ---
>  drivers/soundwire/amd_manager.c   | 130 ++++++++++++++++++++++++++++++
>  drivers/soundwire/amd_manager.h   |   1 +
>  include/linux/soundwire/sdw_amd.h |   7 ++
>  3 files changed, 138 insertions(+)
> 
> diff --git a/drivers/soundwire/amd_manager.c b/drivers/soundwire/amd_manager.c
> index dd7fd4036d89..165078beca2e 100644
> --- a/drivers/soundwire/amd_manager.c
> +++ b/drivers/soundwire/amd_manager.c
> @@ -357,6 +357,51 @@ static enum sdw_command_response amd_sdw_xfer_msg(struct sdw_bus *bus, struct sd
>  	return SDW_CMD_OK;
>  }
>  
> +static void amd_sdw_fill_slave_status(struct amd_sdw_manager *amd_manager, u16 index, u32 status)
> +{
> +	switch (status) {
> +	case SDW_SLAVE_ATTACHED:
> +		amd_manager->status[index] = SDW_SLAVE_ATTACHED;
> +		break;
> +	case SDW_SLAVE_UNATTACHED:
> +		amd_manager->status[index] = SDW_SLAVE_UNATTACHED;
> +		break;
> +	case SDW_SLAVE_ALERT:
> +		amd_manager->status[index] = SDW_SLAVE_ALERT;
> +		break;

why not:

        case SDW_SLAVE_ATTACHED:
        case SDW_SLAVE_UNATTACHED:
        case SDW_SLAVE_ALERT:
                amd_manager->status[index] = status;
                break;

> +	default:
> +		amd_manager->status[index] = SDW_SLAVE_RESERVED;
> +		break;
> +	}
> +}
> +
> +static void amd_sdw_process_ping_status(u64 response, struct amd_sdw_manager *amd_manager)
> +{
> +	u64 slave_stat;
> +	u32 val;
> +	u16 dev_index;
> +
> +	/* slave status response */
> +	slave_stat = FIELD_GET(AMD_SDW_MCP_SLAVE_STAT_0_3, response);
> +	slave_stat |= FIELD_GET(AMD_SDW_MCP_SLAVE_STAT_4_11, response) << 8;
> +	dev_dbg(amd_manager->dev, "slave_stat:0x%llx\n", slave_stat);
> +	for (dev_index = 0; dev_index <= SDW_MAX_DEVICES; ++dev_index) {
> +		val = (slave_stat >> (dev_index * 2)) & AMD_SDW_MCP_SLAVE_STATUS_MASK;
> +		dev_dbg(amd_manager->dev, "val:0x%x\n", val);
> +		amd_sdw_fill_slave_status(amd_manager, dev_index, val);
> +	}
> +}
> +
> +static void amd_sdw_read_and_process_ping_status(struct amd_sdw_manager *amd_manager)
> +{
> +	u64 response;
> +
> +	mutex_lock(&amd_manager->bus.msg_lock);
> +	response = amd_sdw_send_cmd_get_resp(amd_manager, 0, 0);
> +	mutex_unlock(&amd_manager->bus.msg_lock);
> +	amd_sdw_process_ping_status(response, amd_manager);
> +}
> +
>  static u32 amd_sdw_read_ping_status(struct sdw_bus *bus)
>  {
>  	struct amd_sdw_manager *amd_manager = to_amd_sdw(bus);
> @@ -757,6 +802,89 @@ static int amd_sdw_register_dais(struct amd_sdw_manager *amd_manager)
>  					       dais, num_dais);
>  }
>  
> +static void amd_sdw_update_slave_status_work(struct work_struct *work)
> +{
> +	struct amd_sdw_manager *amd_manager =
> +		container_of(work, struct amd_sdw_manager, amd_sdw_work);
> +	int retry_count = 0;
> +
> +	if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
> +		acp_reg_writel(0, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
> +		acp_reg_writel(0, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
> +	}
> +
> +update_status:
> +	sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);
> +	/*
> +	 * During the peripheral enumeration sequence, the SoundWire manager interrupts
> +	 * are masked. Once the device number programming is done for all peripherals,
> +	 * interrupts will be unmasked. Read the peripheral device status from ping command
> +	 * and process the response. This sequence will ensure all peripheral devices enumerated
> +	 * and initialized properly.
> +	 */
> +	if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
> +		if (retry_count++ < SDW_MAX_DEVICES) {
> +			acp_reg_writel(AMD_SDW_IRQ_MASK_0TO7, amd_manager->mmio +
> +				       ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
> +			acp_reg_writel(AMD_SDW_IRQ_MASK_8TO11,
> +				       amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
> +			amd_sdw_read_and_process_ping_status(amd_manager);
> +			goto update_status;

goto are mostly used for error handling, i dont thing case here deserves
a goto, can you please change this...

> +		} else {
> +			dev_err_ratelimited(amd_manager->dev,
> +					    "Device0 detected after %d iterations\n",
> +					    retry_count);
> +		}
> +	}
> +}
> +
> +static void amd_sdw_update_slave_status(u32 status_change_0to7, u32 status_change_8to11,
> +					struct amd_sdw_manager *amd_manager)
> +{
> +	u64 slave_stat;
> +	u32 val;
> +	int dev_index;
> +
> +	if (status_change_0to7 == AMD_SDW_SLAVE_0_ATTACHED)
> +		memset(amd_manager->status, 0, sizeof(amd_manager->status));
> +	slave_stat = status_change_0to7;
> +	slave_stat |= FIELD_GET(AMD_SDW_MCP_SLAVE_STATUS_8TO_11, status_change_8to11) << 32;
> +	dev_dbg(amd_manager->dev, "status_change_0to7:0x%x status_change_8to11:0x%x\n",
> +		status_change_0to7, status_change_8to11);
> +	if (slave_stat) {
> +		for (dev_index = 0; dev_index <= SDW_MAX_DEVICES; ++dev_index) {
> +			if (slave_stat & AMD_SDW_MCP_SLAVE_STATUS_VALID_MASK(dev_index)) {
> +				val = (slave_stat >> AMD_SDW_MCP_SLAVE_STAT_SHIFT_MASK(dev_index)) &
> +				      AMD_SDW_MCP_SLAVE_STATUS_MASK;
> +				amd_sdw_fill_slave_status(amd_manager, dev_index, val);
> +			}
> +		}
> +	}
> +}
> +
> +static void amd_sdw_irq_thread(struct work_struct *work)
> +{
> +	struct amd_sdw_manager *amd_manager =
> +			container_of(work, struct amd_sdw_manager, amd_sdw_irq_thread);
> +	u32 status_change_8to11;
> +	u32 status_change_0to7;
> +
> +	status_change_8to11 = acp_reg_readl(amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_8TO11);
> +	status_change_0to7 = acp_reg_readl(amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_0TO7);
> +	dev_dbg(amd_manager->dev, "[SDW%d] SDW INT: 0to7=0x%x, 8to11=0x%x\n",
> +		amd_manager->instance, status_change_0to7, status_change_8to11);
> +	if (status_change_8to11 & AMD_SDW_PREQ_INTR_STAT) {
> +		amd_sdw_read_and_process_ping_status(amd_manager);
> +	} else {
> +		/* Check for the updated status on peripheral device */
> +		amd_sdw_update_slave_status(status_change_0to7, status_change_8to11, amd_manager);
> +	}
> +	if (status_change_8to11 || status_change_0to7)
> +		schedule_work(&amd_manager->amd_sdw_work);
> +	acp_reg_writel(0x00, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_8TO11);
> +	acp_reg_writel(0x00, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_0TO7);
> +}
> +
>  static void amd_sdw_probe_work(struct work_struct *work)
>  {
>  	struct amd_sdw_manager *amd_manager = container_of(work, struct amd_sdw_manager,
> @@ -847,6 +975,8 @@ static int amd_sdw_manager_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  	dev_set_drvdata(dev, amd_manager);
> +	INIT_WORK(&amd_manager->amd_sdw_irq_thread, amd_sdw_irq_thread);
> +	INIT_WORK(&amd_manager->amd_sdw_work, amd_sdw_update_slave_status_work);
>  	INIT_WORK(&amd_manager->probe_work, amd_sdw_probe_work);
>  	/*
>  	 * Instead of having lengthy probe sequence, use deferred probe.
> diff --git a/drivers/soundwire/amd_manager.h b/drivers/soundwire/amd_manager.h
> index cad26034087b..807bc5a314d8 100644
> --- a/drivers/soundwire/amd_manager.h
> +++ b/drivers/soundwire/amd_manager.h
> @@ -185,6 +185,7 @@
>  #define AMD_SDW1_PAD_KEEPER_EN_MASK			0x10
>  #define AMD_SDW0_PAD_KEEPER_DISABLE_MASK		0x1E
>  #define AMD_SDW1_PAD_KEEPER_DISABLE_MASK		0xF
> +#define AMD_SDW_PREQ_INTR_STAT				BIT(19)
>  
>  enum amd_sdw_cmd_type {
>  	AMD_SDW_CMD_PING = 0,
> diff --git a/include/linux/soundwire/sdw_amd.h b/include/linux/soundwire/sdw_amd.h
> index ac537419301d..df60bc0de6fc 100644
> --- a/include/linux/soundwire/sdw_amd.h
> +++ b/include/linux/soundwire/sdw_amd.h
> @@ -45,8 +45,11 @@ struct sdw_amd_dai_runtime {
>   * @mmio: SoundWire registers mmio base
>   * @acp_mmio: acp registers mmio base
>   * @reg_mask: register mask structure per manager instance
> + * @amd_sdw_irq_thread: SoundWire manager irq workqueue
> + * @amd_sdw_work: peripheral status work queue
>   * @probe_work: SoundWire manager probe workqueue
>   * @acp_sdw_lock: mutex to protect acp share register access
> + * @status: peripheral devices status array
>   * @num_din_ports: number of input ports
>   * @num_dout_ports: number of output ports
>   * @cols_index: Column index in frame shape
> @@ -65,10 +68,14 @@ struct amd_sdw_manager {
>  	void __iomem *acp_mmio;
>  
>  	struct sdw_manager_reg_mask *reg_mask;
> +	struct work_struct amd_sdw_irq_thread;
> +	struct work_struct amd_sdw_work;
>  	struct work_struct probe_work;
>  	/* mutex to protect acp common register access */
>  	struct mutex *acp_sdw_lock;
>  
> +	enum sdw_slave_status status[SDW_MAX_DEVICES + 1];
> +
>  	int num_din_ports;
>  	int num_dout_ports;
>  
> -- 
> 2.34.1
  
Mukunda,Vijendar March 16, 2023, 5:04 p.m. UTC | #2
On 15/03/23 15:36, Vinod Koul wrote:
> On 07-03-23, 19:01, Vijendar Mukunda wrote:
>> Add support for handling SoundWire manager interrupts.
>>
>> Signed-off-by: Vijendar Mukunda <Vijendar.Mukunda@amd.com>
>> Signed-off-by: Mastan Katragadda <Mastan.Katragadda@amd.com>
>> Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
>> Link: https://lore.kernel.org/lkml/20230227154801.50319-6-Vijendar.Mukunda@amd.com
>> ---
>>  drivers/soundwire/amd_manager.c   | 130 ++++++++++++++++++++++++++++++
>>  drivers/soundwire/amd_manager.h   |   1 +
>>  include/linux/soundwire/sdw_amd.h |   7 ++
>>  3 files changed, 138 insertions(+)
>>
>> diff --git a/drivers/soundwire/amd_manager.c b/drivers/soundwire/amd_manager.c
>> index dd7fd4036d89..165078beca2e 100644
>> --- a/drivers/soundwire/amd_manager.c
>> +++ b/drivers/soundwire/amd_manager.c
>> @@ -357,6 +357,51 @@ static enum sdw_command_response amd_sdw_xfer_msg(struct sdw_bus *bus, struct sd
>>  	return SDW_CMD_OK;
>>  }
>>  
>> +static void amd_sdw_fill_slave_status(struct amd_sdw_manager *amd_manager, u16 index, u32 status)
>> +{
>> +	switch (status) {
>> +	case SDW_SLAVE_ATTACHED:
>> +		amd_manager->status[index] = SDW_SLAVE_ATTACHED;
>> +		break;
>> +	case SDW_SLAVE_UNATTACHED:
>> +		amd_manager->status[index] = SDW_SLAVE_UNATTACHED;
>> +		break;
>> +	case SDW_SLAVE_ALERT:
>> +		amd_manager->status[index] = SDW_SLAVE_ALERT;
>> +		break;
> why not:
>
>         case SDW_SLAVE_ATTACHED:
>         case SDW_SLAVE_UNATTACHED:
>         case SDW_SLAVE_ALERT:
>                 amd_manager->status[index] = status;
>                 break;
>
> Will fix it.
>> +	default:
>> +		amd_manager->status[index] = SDW_SLAVE_RESERVED;
>> +		break;
>> +	}
>> +}
>> +
>> +static void amd_sdw_process_ping_status(u64 response, struct amd_sdw_manager *amd_manager)
>> +{
>> +	u64 slave_stat;
>> +	u32 val;
>> +	u16 dev_index;
>> +
>> +	/* slave status response */
>> +	slave_stat = FIELD_GET(AMD_SDW_MCP_SLAVE_STAT_0_3, response);
>> +	slave_stat |= FIELD_GET(AMD_SDW_MCP_SLAVE_STAT_4_11, response) << 8;
>> +	dev_dbg(amd_manager->dev, "slave_stat:0x%llx\n", slave_stat);
>> +	for (dev_index = 0; dev_index <= SDW_MAX_DEVICES; ++dev_index) {
>> +		val = (slave_stat >> (dev_index * 2)) & AMD_SDW_MCP_SLAVE_STATUS_MASK;
>> +		dev_dbg(amd_manager->dev, "val:0x%x\n", val);
>> +		amd_sdw_fill_slave_status(amd_manager, dev_index, val);
>> +	}
>> +}
>> +
>> +static void amd_sdw_read_and_process_ping_status(struct amd_sdw_manager *amd_manager)
>> +{
>> +	u64 response;
>> +
>> +	mutex_lock(&amd_manager->bus.msg_lock);
>> +	response = amd_sdw_send_cmd_get_resp(amd_manager, 0, 0);
>> +	mutex_unlock(&amd_manager->bus.msg_lock);
>> +	amd_sdw_process_ping_status(response, amd_manager);
>> +}
>> +
>>  static u32 amd_sdw_read_ping_status(struct sdw_bus *bus)
>>  {
>>  	struct amd_sdw_manager *amd_manager = to_amd_sdw(bus);
>> @@ -757,6 +802,89 @@ static int amd_sdw_register_dais(struct amd_sdw_manager *amd_manager)
>>  					       dais, num_dais);
>>  }
>>  
>> +static void amd_sdw_update_slave_status_work(struct work_struct *work)
>> +{
>> +	struct amd_sdw_manager *amd_manager =
>> +		container_of(work, struct amd_sdw_manager, amd_sdw_work);
>> +	int retry_count = 0;
>> +
>> +	if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
>> +		acp_reg_writel(0, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
>> +		acp_reg_writel(0, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
>> +	}
>> +
>> +update_status:
>> +	sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);
>> +	/*
>> +	 * During the peripheral enumeration sequence, the SoundWire manager interrupts
>> +	 * are masked. Once the device number programming is done for all peripherals,
>> +	 * interrupts will be unmasked. Read the peripheral device status from ping command
>> +	 * and process the response. This sequence will ensure all peripheral devices enumerated
>> +	 * and initialized properly.
>> +	 */
>> +	if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
>> +		if (retry_count++ < SDW_MAX_DEVICES) {
>> +			acp_reg_writel(AMD_SDW_IRQ_MASK_0TO7, amd_manager->mmio +
>> +				       ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
>> +			acp_reg_writel(AMD_SDW_IRQ_MASK_8TO11,
>> +				       amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
>> +			amd_sdw_read_and_process_ping_status(amd_manager);
>> +			goto update_status;
> goto are mostly used for error handling, i dont thing case here deserves
> a goto, can you please change this...
I agree. goto statements will be used mostly for error handling.
But this is a different scenario. We have used goto statement to call sdw_handle_slave_status()
from if statement to make sure all peripheral devices are enumerated and initialized properly.
Please let us know if you are expecting code to be modified as mentioned below.

sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);

if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
	acp_reg_writel(AMD_SDW_IRQ_MASK_0TO7, amd_manager->mmio +
		       ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
	acp_reg_writel(AMD_SDW_IRQ_MASK_8TO11,
		       amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
	amd_sdw_read_and_process_ping_status(amd_manager);
	sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);
}

We have to check any race conditions occurs or not if we implement code as mentioned
above.
IMHO, it is still good to go with goto statement implementation.
>> +		} else {
>> +			dev_err_ratelimited(amd_manager->dev,
>> +					    "Device0 detected after %d iterations\n",
>> +					    retry_count);
>> +		}
>> +	}
>> +}
>> +
>> +static void amd_sdw_update_slave_status(u32 status_change_0to7, u32 status_change_8to11,
>> +					struct amd_sdw_manager *amd_manager)
>> +{
>> +	u64 slave_stat;
>> +	u32 val;
>> +	int dev_index;
>> +
>> +	if (status_change_0to7 == AMD_SDW_SLAVE_0_ATTACHED)
>> +		memset(amd_manager->status, 0, sizeof(amd_manager->status));
>> +	slave_stat = status_change_0to7;
>> +	slave_stat |= FIELD_GET(AMD_SDW_MCP_SLAVE_STATUS_8TO_11, status_change_8to11) << 32;
>> +	dev_dbg(amd_manager->dev, "status_change_0to7:0x%x status_change_8to11:0x%x\n",
>> +		status_change_0to7, status_change_8to11);
>> +	if (slave_stat) {
>> +		for (dev_index = 0; dev_index <= SDW_MAX_DEVICES; ++dev_index) {
>> +			if (slave_stat & AMD_SDW_MCP_SLAVE_STATUS_VALID_MASK(dev_index)) {
>> +				val = (slave_stat >> AMD_SDW_MCP_SLAVE_STAT_SHIFT_MASK(dev_index)) &
>> +				      AMD_SDW_MCP_SLAVE_STATUS_MASK;
>> +				amd_sdw_fill_slave_status(amd_manager, dev_index, val);
>> +			}
>> +		}
>> +	}
>> +}
>> +
>> +static void amd_sdw_irq_thread(struct work_struct *work)
>> +{
>> +	struct amd_sdw_manager *amd_manager =
>> +			container_of(work, struct amd_sdw_manager, amd_sdw_irq_thread);
>> +	u32 status_change_8to11;
>> +	u32 status_change_0to7;
>> +
>> +	status_change_8to11 = acp_reg_readl(amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_8TO11);
>> +	status_change_0to7 = acp_reg_readl(amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_0TO7);
>> +	dev_dbg(amd_manager->dev, "[SDW%d] SDW INT: 0to7=0x%x, 8to11=0x%x\n",
>> +		amd_manager->instance, status_change_0to7, status_change_8to11);
>> +	if (status_change_8to11 & AMD_SDW_PREQ_INTR_STAT) {
>> +		amd_sdw_read_and_process_ping_status(amd_manager);
>> +	} else {
>> +		/* Check for the updated status on peripheral device */
>> +		amd_sdw_update_slave_status(status_change_0to7, status_change_8to11, amd_manager);
>> +	}
>> +	if (status_change_8to11 || status_change_0to7)
>> +		schedule_work(&amd_manager->amd_sdw_work);
>> +	acp_reg_writel(0x00, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_8TO11);
>> +	acp_reg_writel(0x00, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_0TO7);
>> +}
>> +
>>  static void amd_sdw_probe_work(struct work_struct *work)
>>  {
>>  	struct amd_sdw_manager *amd_manager = container_of(work, struct amd_sdw_manager,
>> @@ -847,6 +975,8 @@ static int amd_sdw_manager_probe(struct platform_device *pdev)
>>  		return ret;
>>  	}
>>  	dev_set_drvdata(dev, amd_manager);
>> +	INIT_WORK(&amd_manager->amd_sdw_irq_thread, amd_sdw_irq_thread);
>> +	INIT_WORK(&amd_manager->amd_sdw_work, amd_sdw_update_slave_status_work);
>>  	INIT_WORK(&amd_manager->probe_work, amd_sdw_probe_work);
>>  	/*
>>  	 * Instead of having lengthy probe sequence, use deferred probe.
>> diff --git a/drivers/soundwire/amd_manager.h b/drivers/soundwire/amd_manager.h
>> index cad26034087b..807bc5a314d8 100644
>> --- a/drivers/soundwire/amd_manager.h
>> +++ b/drivers/soundwire/amd_manager.h
>> @@ -185,6 +185,7 @@
>>  #define AMD_SDW1_PAD_KEEPER_EN_MASK			0x10
>>  #define AMD_SDW0_PAD_KEEPER_DISABLE_MASK		0x1E
>>  #define AMD_SDW1_PAD_KEEPER_DISABLE_MASK		0xF
>> +#define AMD_SDW_PREQ_INTR_STAT				BIT(19)
>>  
>>  enum amd_sdw_cmd_type {
>>  	AMD_SDW_CMD_PING = 0,
>> diff --git a/include/linux/soundwire/sdw_amd.h b/include/linux/soundwire/sdw_amd.h
>> index ac537419301d..df60bc0de6fc 100644
>> --- a/include/linux/soundwire/sdw_amd.h
>> +++ b/include/linux/soundwire/sdw_amd.h
>> @@ -45,8 +45,11 @@ struct sdw_amd_dai_runtime {
>>   * @mmio: SoundWire registers mmio base
>>   * @acp_mmio: acp registers mmio base
>>   * @reg_mask: register mask structure per manager instance
>> + * @amd_sdw_irq_thread: SoundWire manager irq workqueue
>> + * @amd_sdw_work: peripheral status work queue
>>   * @probe_work: SoundWire manager probe workqueue
>>   * @acp_sdw_lock: mutex to protect acp share register access
>> + * @status: peripheral devices status array
>>   * @num_din_ports: number of input ports
>>   * @num_dout_ports: number of output ports
>>   * @cols_index: Column index in frame shape
>> @@ -65,10 +68,14 @@ struct amd_sdw_manager {
>>  	void __iomem *acp_mmio;
>>  
>>  	struct sdw_manager_reg_mask *reg_mask;
>> +	struct work_struct amd_sdw_irq_thread;
>> +	struct work_struct amd_sdw_work;
>>  	struct work_struct probe_work;
>>  	/* mutex to protect acp common register access */
>>  	struct mutex *acp_sdw_lock;
>>  
>> +	enum sdw_slave_status status[SDW_MAX_DEVICES + 1];
>> +
>>  	int num_din_ports;
>>  	int num_dout_ports;
>>  
>> -- 
>> 2.34.1
  
Vinod Koul March 17, 2023, 1:36 p.m. UTC | #3
On 16-03-23, 22:34, Mukunda,Vijendar wrote:
> On 15/03/23 15:36, Vinod Koul wrote:
> > On 07-03-23, 19:01, Vijendar Mukunda wrote:

> >> +static void amd_sdw_update_slave_status_work(struct work_struct *work)
> >> +{
> >> +	struct amd_sdw_manager *amd_manager =
> >> +		container_of(work, struct amd_sdw_manager, amd_sdw_work);
> >> +	int retry_count = 0;
> >> +
> >> +	if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
> >> +		acp_reg_writel(0, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
> >> +		acp_reg_writel(0, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
> >> +	}
> >> +
> >> +update_status:
> >> +	sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);
> >> +	/*
> >> +	 * During the peripheral enumeration sequence, the SoundWire manager interrupts
> >> +	 * are masked. Once the device number programming is done for all peripherals,
> >> +	 * interrupts will be unmasked. Read the peripheral device status from ping command
> >> +	 * and process the response. This sequence will ensure all peripheral devices enumerated
> >> +	 * and initialized properly.
> >> +	 */
> >> +	if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
> >> +		if (retry_count++ < SDW_MAX_DEVICES) {
> >> +			acp_reg_writel(AMD_SDW_IRQ_MASK_0TO7, amd_manager->mmio +
> >> +				       ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
> >> +			acp_reg_writel(AMD_SDW_IRQ_MASK_8TO11,
> >> +				       amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
> >> +			amd_sdw_read_and_process_ping_status(amd_manager);
> >> +			goto update_status;
> > goto are mostly used for error handling, i dont thing case here deserves
> > a goto, can you please change this...
> I agree. goto statements will be used mostly for error handling.
> But this is a different scenario. We have used goto statement to call sdw_handle_slave_status()
> from if statement to make sure all peripheral devices are enumerated and initialized properly.
> Please let us know if you are expecting code to be modified as mentioned below.
> 
> sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);
> 
> if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
> 	acp_reg_writel(AMD_SDW_IRQ_MASK_0TO7, amd_manager->mmio +
> 		       ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
> 	acp_reg_writel(AMD_SDW_IRQ_MASK_8TO11,
> 		       amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
> 	amd_sdw_read_and_process_ping_status(amd_manager);
> 	sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);
> }
> 
> We have to check any race conditions occurs or not if we implement code as mentioned
> above.

what race are you talking about

> IMHO, it is still good to go with goto statement implementation.

Since you keep checking, essentially this seems to be a loop?
  
Mukunda,Vijendar March 17, 2023, 2:46 p.m. UTC | #4
On 17/03/23 19:06, Vinod Koul wrote:
> On 16-03-23, 22:34, Mukunda,Vijendar wrote:
>> On 15/03/23 15:36, Vinod Koul wrote:
>>> On 07-03-23, 19:01, Vijendar Mukunda wrote:
>>>> +static void amd_sdw_update_slave_status_work(struct work_struct *work)
>>>> +{
>>>> +	struct amd_sdw_manager *amd_manager =
>>>> +		container_of(work, struct amd_sdw_manager, amd_sdw_work);
>>>> +	int retry_count = 0;
>>>> +
>>>> +	if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
>>>> +		acp_reg_writel(0, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
>>>> +		acp_reg_writel(0, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
>>>> +	}
>>>> +
>>>> +update_status:
>>>> +	sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);
>>>> +	/*
>>>> +	 * During the peripheral enumeration sequence, the SoundWire manager interrupts
>>>> +	 * are masked. Once the device number programming is done for all peripherals,
>>>> +	 * interrupts will be unmasked. Read the peripheral device status from ping command
>>>> +	 * and process the response. This sequence will ensure all peripheral devices enumerated
>>>> +	 * and initialized properly.
>>>> +	 */
>>>> +	if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
>>>> +		if (retry_count++ < SDW_MAX_DEVICES) {
>>>> +			acp_reg_writel(AMD_SDW_IRQ_MASK_0TO7, amd_manager->mmio +
>>>> +				       ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
>>>> +			acp_reg_writel(AMD_SDW_IRQ_MASK_8TO11,
>>>> +				       amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
>>>> +			amd_sdw_read_and_process_ping_status(amd_manager);
>>>> +			goto update_status;
>>> goto are mostly used for error handling, i dont thing case here deserves
>>> a goto, can you please change this...
>> I agree. goto statements will be used mostly for error handling.
>> But this is a different scenario. We have used goto statement to call sdw_handle_slave_status()
>> from if statement to make sure all peripheral devices are enumerated and initialized properly.
>> Please let us know if you are expecting code to be modified as mentioned below.
>>
>> sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);
>>
>> if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
>> 	acp_reg_writel(AMD_SDW_IRQ_MASK_0TO7, amd_manager->mmio +
>> 		       ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
>> 	acp_reg_writel(AMD_SDW_IRQ_MASK_8TO11,
>> 		       amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
>> 	amd_sdw_read_and_process_ping_status(amd_manager);
>> 	sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);
>> }
>>
>> We have to check any race conditions occurs or not if we implement code as mentioned
>> above.
> what race are you talking about
Our intention is to convey that we need to verify the above logic and check
for faulty case handling where status[0] is keep on updated as "ATTACHED"
when multiple peripheral devices are connected over the link.


>
>> IMHO, it is still good to go with goto statement implementation.
> Since you keep checking, essentially this seems to be a loop?
In normal scenario , if condition gets executed once and exits the function.
In faulty case, if status[0] is still reported as ATTACHED, it runs in loop till retry_count
reaches SDW_MAX_DEVICES.
We want to keep checking the status until ping command reports
correct status on all other devices other than "ATTACHED" on device0 in a loop using goto
statement with max retry count.
>
  

Patch

diff --git a/drivers/soundwire/amd_manager.c b/drivers/soundwire/amd_manager.c
index dd7fd4036d89..165078beca2e 100644
--- a/drivers/soundwire/amd_manager.c
+++ b/drivers/soundwire/amd_manager.c
@@ -357,6 +357,51 @@  static enum sdw_command_response amd_sdw_xfer_msg(struct sdw_bus *bus, struct sd
 	return SDW_CMD_OK;
 }
 
+static void amd_sdw_fill_slave_status(struct amd_sdw_manager *amd_manager, u16 index, u32 status)
+{
+	switch (status) {
+	case SDW_SLAVE_ATTACHED:
+		amd_manager->status[index] = SDW_SLAVE_ATTACHED;
+		break;
+	case SDW_SLAVE_UNATTACHED:
+		amd_manager->status[index] = SDW_SLAVE_UNATTACHED;
+		break;
+	case SDW_SLAVE_ALERT:
+		amd_manager->status[index] = SDW_SLAVE_ALERT;
+		break;
+	default:
+		amd_manager->status[index] = SDW_SLAVE_RESERVED;
+		break;
+	}
+}
+
+static void amd_sdw_process_ping_status(u64 response, struct amd_sdw_manager *amd_manager)
+{
+	u64 slave_stat;
+	u32 val;
+	u16 dev_index;
+
+	/* slave status response */
+	slave_stat = FIELD_GET(AMD_SDW_MCP_SLAVE_STAT_0_3, response);
+	slave_stat |= FIELD_GET(AMD_SDW_MCP_SLAVE_STAT_4_11, response) << 8;
+	dev_dbg(amd_manager->dev, "slave_stat:0x%llx\n", slave_stat);
+	for (dev_index = 0; dev_index <= SDW_MAX_DEVICES; ++dev_index) {
+		val = (slave_stat >> (dev_index * 2)) & AMD_SDW_MCP_SLAVE_STATUS_MASK;
+		dev_dbg(amd_manager->dev, "val:0x%x\n", val);
+		amd_sdw_fill_slave_status(amd_manager, dev_index, val);
+	}
+}
+
+static void amd_sdw_read_and_process_ping_status(struct amd_sdw_manager *amd_manager)
+{
+	u64 response;
+
+	mutex_lock(&amd_manager->bus.msg_lock);
+	response = amd_sdw_send_cmd_get_resp(amd_manager, 0, 0);
+	mutex_unlock(&amd_manager->bus.msg_lock);
+	amd_sdw_process_ping_status(response, amd_manager);
+}
+
 static u32 amd_sdw_read_ping_status(struct sdw_bus *bus)
 {
 	struct amd_sdw_manager *amd_manager = to_amd_sdw(bus);
@@ -757,6 +802,89 @@  static int amd_sdw_register_dais(struct amd_sdw_manager *amd_manager)
 					       dais, num_dais);
 }
 
+static void amd_sdw_update_slave_status_work(struct work_struct *work)
+{
+	struct amd_sdw_manager *amd_manager =
+		container_of(work, struct amd_sdw_manager, amd_sdw_work);
+	int retry_count = 0;
+
+	if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
+		acp_reg_writel(0, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
+		acp_reg_writel(0, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
+	}
+
+update_status:
+	sdw_handle_slave_status(&amd_manager->bus, amd_manager->status);
+	/*
+	 * During the peripheral enumeration sequence, the SoundWire manager interrupts
+	 * are masked. Once the device number programming is done for all peripherals,
+	 * interrupts will be unmasked. Read the peripheral device status from ping command
+	 * and process the response. This sequence will ensure all peripheral devices enumerated
+	 * and initialized properly.
+	 */
+	if (amd_manager->status[0] == SDW_SLAVE_ATTACHED) {
+		if (retry_count++ < SDW_MAX_DEVICES) {
+			acp_reg_writel(AMD_SDW_IRQ_MASK_0TO7, amd_manager->mmio +
+				       ACP_SW_STATE_CHANGE_STATUS_MASK_0TO7);
+			acp_reg_writel(AMD_SDW_IRQ_MASK_8TO11,
+				       amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_MASK_8TO11);
+			amd_sdw_read_and_process_ping_status(amd_manager);
+			goto update_status;
+		} else {
+			dev_err_ratelimited(amd_manager->dev,
+					    "Device0 detected after %d iterations\n",
+					    retry_count);
+		}
+	}
+}
+
+static void amd_sdw_update_slave_status(u32 status_change_0to7, u32 status_change_8to11,
+					struct amd_sdw_manager *amd_manager)
+{
+	u64 slave_stat;
+	u32 val;
+	int dev_index;
+
+	if (status_change_0to7 == AMD_SDW_SLAVE_0_ATTACHED)
+		memset(amd_manager->status, 0, sizeof(amd_manager->status));
+	slave_stat = status_change_0to7;
+	slave_stat |= FIELD_GET(AMD_SDW_MCP_SLAVE_STATUS_8TO_11, status_change_8to11) << 32;
+	dev_dbg(amd_manager->dev, "status_change_0to7:0x%x status_change_8to11:0x%x\n",
+		status_change_0to7, status_change_8to11);
+	if (slave_stat) {
+		for (dev_index = 0; dev_index <= SDW_MAX_DEVICES; ++dev_index) {
+			if (slave_stat & AMD_SDW_MCP_SLAVE_STATUS_VALID_MASK(dev_index)) {
+				val = (slave_stat >> AMD_SDW_MCP_SLAVE_STAT_SHIFT_MASK(dev_index)) &
+				      AMD_SDW_MCP_SLAVE_STATUS_MASK;
+				amd_sdw_fill_slave_status(amd_manager, dev_index, val);
+			}
+		}
+	}
+}
+
+static void amd_sdw_irq_thread(struct work_struct *work)
+{
+	struct amd_sdw_manager *amd_manager =
+			container_of(work, struct amd_sdw_manager, amd_sdw_irq_thread);
+	u32 status_change_8to11;
+	u32 status_change_0to7;
+
+	status_change_8to11 = acp_reg_readl(amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_8TO11);
+	status_change_0to7 = acp_reg_readl(amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_0TO7);
+	dev_dbg(amd_manager->dev, "[SDW%d] SDW INT: 0to7=0x%x, 8to11=0x%x\n",
+		amd_manager->instance, status_change_0to7, status_change_8to11);
+	if (status_change_8to11 & AMD_SDW_PREQ_INTR_STAT) {
+		amd_sdw_read_and_process_ping_status(amd_manager);
+	} else {
+		/* Check for the updated status on peripheral device */
+		amd_sdw_update_slave_status(status_change_0to7, status_change_8to11, amd_manager);
+	}
+	if (status_change_8to11 || status_change_0to7)
+		schedule_work(&amd_manager->amd_sdw_work);
+	acp_reg_writel(0x00, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_8TO11);
+	acp_reg_writel(0x00, amd_manager->mmio + ACP_SW_STATE_CHANGE_STATUS_0TO7);
+}
+
 static void amd_sdw_probe_work(struct work_struct *work)
 {
 	struct amd_sdw_manager *amd_manager = container_of(work, struct amd_sdw_manager,
@@ -847,6 +975,8 @@  static int amd_sdw_manager_probe(struct platform_device *pdev)
 		return ret;
 	}
 	dev_set_drvdata(dev, amd_manager);
+	INIT_WORK(&amd_manager->amd_sdw_irq_thread, amd_sdw_irq_thread);
+	INIT_WORK(&amd_manager->amd_sdw_work, amd_sdw_update_slave_status_work);
 	INIT_WORK(&amd_manager->probe_work, amd_sdw_probe_work);
 	/*
 	 * Instead of having lengthy probe sequence, use deferred probe.
diff --git a/drivers/soundwire/amd_manager.h b/drivers/soundwire/amd_manager.h
index cad26034087b..807bc5a314d8 100644
--- a/drivers/soundwire/amd_manager.h
+++ b/drivers/soundwire/amd_manager.h
@@ -185,6 +185,7 @@ 
 #define AMD_SDW1_PAD_KEEPER_EN_MASK			0x10
 #define AMD_SDW0_PAD_KEEPER_DISABLE_MASK		0x1E
 #define AMD_SDW1_PAD_KEEPER_DISABLE_MASK		0xF
+#define AMD_SDW_PREQ_INTR_STAT				BIT(19)
 
 enum amd_sdw_cmd_type {
 	AMD_SDW_CMD_PING = 0,
diff --git a/include/linux/soundwire/sdw_amd.h b/include/linux/soundwire/sdw_amd.h
index ac537419301d..df60bc0de6fc 100644
--- a/include/linux/soundwire/sdw_amd.h
+++ b/include/linux/soundwire/sdw_amd.h
@@ -45,8 +45,11 @@  struct sdw_amd_dai_runtime {
  * @mmio: SoundWire registers mmio base
  * @acp_mmio: acp registers mmio base
  * @reg_mask: register mask structure per manager instance
+ * @amd_sdw_irq_thread: SoundWire manager irq workqueue
+ * @amd_sdw_work: peripheral status work queue
  * @probe_work: SoundWire manager probe workqueue
  * @acp_sdw_lock: mutex to protect acp share register access
+ * @status: peripheral devices status array
  * @num_din_ports: number of input ports
  * @num_dout_ports: number of output ports
  * @cols_index: Column index in frame shape
@@ -65,10 +68,14 @@  struct amd_sdw_manager {
 	void __iomem *acp_mmio;
 
 	struct sdw_manager_reg_mask *reg_mask;
+	struct work_struct amd_sdw_irq_thread;
+	struct work_struct amd_sdw_work;
 	struct work_struct probe_work;
 	/* mutex to protect acp common register access */
 	struct mutex *acp_sdw_lock;
 
+	enum sdw_slave_status status[SDW_MAX_DEVICES + 1];
+
 	int num_din_ports;
 	int num_dout_ports;