Re: [PATCH 5/6] remoteproc: qcom: pas: Add late attach support for subsystems

[Jingyi Wang <jingyi.wang@oss.qualcomm.com>]

On 9/25/2025 11:04 AM, Dmitry Baryshkov wrote:
> On Wed, Sep 24, 2025 at 04:37:26PM -0700, Jingyi Wang wrote:
>> From: Gokul krishna Krishnakumar <Gokul.krishnakumar@oss.qualcomm>
>>
>> Subsystems can be brought out of reset by entities such as
>> bootloaders. Before attaching such subsystems, it is important to
>> check the state of the subsystem. This patch adds support to attach
>> to a subsystem by ensuring that the subsystem is in a sane state by
>> reading SMP2P bits and pinging the subsystem.
>>
>> Signed-off-by: Gokul krishna Krishnakumar <Gokul.krishnakumar@oss.qualcomm>
>> Co-developed-by: Jingyi Wang <jingyi.wang@oss.qualcomm.com>
>> Signed-off-by: Jingyi Wang <jingyi.wang@oss.qualcomm.com>
>> ---
>>  drivers/remoteproc/qcom_q6v5.c      | 89 ++++++++++++++++++++++++++++++++++++-
>>  drivers/remoteproc/qcom_q6v5.h      | 14 +++++-
>>  drivers/remoteproc/qcom_q6v5_adsp.c |  2 +-
>>  drivers/remoteproc/qcom_q6v5_mss.c  |  2 +-
>>  drivers/remoteproc/qcom_q6v5_pas.c  | 61 ++++++++++++++++++++++++-
>>  5 files changed, 163 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/remoteproc/qcom_q6v5.c b/drivers/remoteproc/qcom_q6v5.c
>> index 4ee5e67a9f03..cba05e1d6d52 100644
>> --- a/drivers/remoteproc/qcom_q6v5.c
>> +++ b/drivers/remoteproc/qcom_q6v5.c
>> @@ -94,6 +94,9 @@ static irqreturn_t q6v5_wdog_interrupt(int irq, void *data)
>>  	size_t len;
>>  	char *msg;
>>  
>> +	if (q6v5->early_boot)
>> +		complete(&q6v5->subsys_booted);
> 
> Where do we clean this flag? I think you current code breaks restarting
> of ADSP. Once the ADSP is brought up, the flag should be cleared and
> further handling of the ADSP should follow the normal flow.
> 

q6v5->subsys_booted can not be cleared now, it is only checked in the 
qcom_pas_attach callback, so the bootup process will not be infected, 
we have tested shutdown->bootup process and it runs as expected.

Thanks,
Jingyi


>> +
>>  	/* Sometimes the stop triggers a watchdog rather than a stop-ack */
>>  	if (!q6v5->running) {
>>  		complete(&q6v5->stop_done);
>> @@ -118,6 +121,9 @@ static irqreturn_t q6v5_fatal_interrupt(int irq, void *data)
>>  	size_t len;
>>  	char *msg;
>>  
>> +	if (q6v5->early_boot)
>> +		complete(&q6v5->subsys_booted);
>> +
>>  	if (!q6v5->running)
>>  		return IRQ_HANDLED;
>>  
>> @@ -139,6 +145,9 @@ static irqreturn_t q6v5_ready_interrupt(int irq, void *data)
>>  
>>  	complete(&q6v5->start_done);
>>  
>> +	if (q6v5->early_boot)
>> +		complete(&q6v5->subsys_booted);
>> +
>>  	return IRQ_HANDLED;
>>  }
>>  
>> @@ -170,6 +179,9 @@ static irqreturn_t q6v5_handover_interrupt(int irq, void *data)
>>  	if (q6v5->handover)
>>  		q6v5->handover(q6v5);
>>  
>> +	if (q6v5->early_boot)
>> +		complete(&q6v5->subsys_booted);
>> +
>>  	icc_set_bw(q6v5->path, 0, 0);
>>  
>>  	q6v5->handover_issued = true;
>> @@ -232,6 +244,77 @@ unsigned long qcom_q6v5_panic(struct qcom_q6v5 *q6v5)
>>  }
>>  EXPORT_SYMBOL_GPL(qcom_q6v5_panic);
>>  
>> +static irqreturn_t q6v5_pong_interrupt(int irq, void *data)
>> +{
>> +	struct qcom_q6v5 *q6v5 = data;
>> +
>> +	complete(&q6v5->ping_done);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +int qcom_q6v5_ping_subsystem(struct qcom_q6v5 *q6v5)
>> +{
>> +	int ret;
>> +	int ping_failed = 0;
>> +
>> +	reinit_completion(&q6v5->ping_done);
>> +
>> +	/* Set master kernel Ping bit */
>> +	ret = qcom_smem_state_update_bits(q6v5->ping_state,
>> +					  BIT(q6v5->ping_bit), BIT(q6v5->ping_bit));
>> +	if (ret) {
>> +		dev_err(q6v5->dev, "Failed to update ping bits\n");
>> +		return ret;
>> +	}
>> +
>> +	ret = wait_for_completion_timeout(&q6v5->ping_done, msecs_to_jiffies(PING_TIMEOUT));
>> +	if (!ret) {
>> +		ping_failed = -ETIMEDOUT;
>> +		dev_err(q6v5->dev, "Failed to get back pong\n");
>> +	}
>> +
>> +	/* Clear ping bit master kernel */
>> +	ret = qcom_smem_state_update_bits(q6v5->ping_state, BIT(q6v5->ping_bit), 0);
>> +	if (ret) {
>> +		pr_err("Failed to clear master kernel bits\n");
>> +		return ret;
>> +	}
>> +
>> +	if (ping_failed)
>> +		return ping_failed;
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(qcom_q6v5_ping_subsystem);
>> +
>> +int qcom_q6v5_ping_subsystem_init(struct qcom_q6v5 *q6v5, struct platform_device *pdev)
>> +{
>> +	int ret = -ENODEV;
>> +
>> +	q6v5->ping_state = devm_qcom_smem_state_get(&pdev->dev, "ping", &q6v5->ping_bit);
>> +	if (IS_ERR(q6v5->ping_state)) {
>> +		dev_err(&pdev->dev, "failed to acquire smem state %ld\n",
>> +			PTR_ERR(q6v5->ping_state));
>> +		return ret;
>> +	}
>> +
>> +	q6v5->pong_irq = platform_get_irq_byname(pdev, "pong");
>> +	if (q6v5->pong_irq < 0)
>> +		return q6v5->pong_irq;
>> +
>> +	ret = devm_request_threaded_irq(&pdev->dev, q6v5->pong_irq, NULL,
>> +					q6v5_pong_interrupt, IRQF_TRIGGER_RISING | IRQF_ONESHOT,
>> +					"q6v5 pong", q6v5);
>> +	if (ret)
>> +		dev_err(&pdev->dev, "failed to acquire pong IRQ\n");
>> +
>> +	init_completion(&q6v5->ping_done);
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(qcom_q6v5_ping_subsystem_init);
>> +
>>  /**
>>   * qcom_q6v5_init() - initializer of the q6v5 common struct
>>   * @q6v5:	handle to be initialized
>> @@ -245,7 +328,7 @@ EXPORT_SYMBOL_GPL(qcom_q6v5_panic);
>>   */
>>  int qcom_q6v5_init(struct qcom_q6v5 *q6v5, struct platform_device *pdev,
>>  		   struct rproc *rproc, int crash_reason, const char *load_state,
>> -		   void (*handover)(struct qcom_q6v5 *q6v5))
>> +		   bool early_boot, void (*handover)(struct qcom_q6v5 *q6v5))
>>  {
>>  	int ret;
>>  
>> @@ -253,10 +336,14 @@ int qcom_q6v5_init(struct qcom_q6v5 *q6v5, struct platform_device *pdev,
>>  	q6v5->dev = &pdev->dev;
>>  	q6v5->crash_reason = crash_reason;
>>  	q6v5->handover = handover;
>> +	q6v5->early_boot = early_boot;
>>  
>>  	init_completion(&q6v5->start_done);
>>  	init_completion(&q6v5->stop_done);
>>  
>> +	if (early_boot)
>> +		init_completion(&q6v5->subsys_booted);
>> +
>>  	q6v5->wdog_irq = platform_get_irq_byname(pdev, "wdog");
>>  	if (q6v5->wdog_irq < 0)
>>  		return q6v5->wdog_irq;
>> diff --git a/drivers/remoteproc/qcom_q6v5.h b/drivers/remoteproc/qcom_q6v5.h
>> index 5a859c41896e..8a227bf70d7e 100644
>> --- a/drivers/remoteproc/qcom_q6v5.h
>> +++ b/drivers/remoteproc/qcom_q6v5.h
>> @@ -12,27 +12,35 @@ struct rproc;
>>  struct qcom_smem_state;
>>  struct qcom_sysmon;
>>  
>> +#define PING_TIMEOUT 500 /* in milliseconds */
>> +#define PING_TEST_WAIT 500 /* in milliseconds */
>> +
>>  struct qcom_q6v5 {
>>  	struct device *dev;
>>  	struct rproc *rproc;
>>  
>>  	struct qcom_smem_state *state;
>> +	struct qcom_smem_state *ping_state;
>>  	struct qmp *qmp;
>>  
>>  	struct icc_path *path;
>>  
>>  	unsigned stop_bit;
>> +	unsigned int ping_bit;
>>  
>>  	int wdog_irq;
>>  	int fatal_irq;
>>  	int ready_irq;
>>  	int handover_irq;
>>  	int stop_irq;
>> +	int pong_irq;
>>  
>>  	bool handover_issued;
>>  
>>  	struct completion start_done;
>>  	struct completion stop_done;
>> +	struct completion subsys_booted;
>> +	struct completion ping_done;
>>  
>>  	int crash_reason;
>>  
>> @@ -40,11 +48,13 @@ struct qcom_q6v5 {
>>  
>>  	const char *load_state;
>>  	void (*handover)(struct qcom_q6v5 *q6v5);
>> +
>> +	bool early_boot;
>>  };
>>  
>>  int qcom_q6v5_init(struct qcom_q6v5 *q6v5, struct platform_device *pdev,
>>  		   struct rproc *rproc, int crash_reason, const char *load_state,
>> -		   void (*handover)(struct qcom_q6v5 *q6v5));
>> +		   bool early_boot, void (*handover)(struct qcom_q6v5 *q6v5));
>>  void qcom_q6v5_deinit(struct qcom_q6v5 *q6v5);
>>  
>>  int qcom_q6v5_prepare(struct qcom_q6v5 *q6v5);
>> @@ -52,5 +62,7 @@ int qcom_q6v5_unprepare(struct qcom_q6v5 *q6v5);
>>  int qcom_q6v5_request_stop(struct qcom_q6v5 *q6v5, struct qcom_sysmon *sysmon);
>>  int qcom_q6v5_wait_for_start(struct qcom_q6v5 *q6v5, int timeout);
>>  unsigned long qcom_q6v5_panic(struct qcom_q6v5 *q6v5);
>> +int qcom_q6v5_ping_subsystem(struct qcom_q6v5 *q6v5);
>> +int qcom_q6v5_ping_subsystem_init(struct qcom_q6v5 *q6v5, struct platform_device *pdev);
>>  
>>  #endif
>> diff --git a/drivers/remoteproc/qcom_q6v5_adsp.c b/drivers/remoteproc/qcom_q6v5_adsp.c
>> index e98b7e03162c..1576b435b921 100644
>> --- a/drivers/remoteproc/qcom_q6v5_adsp.c
>> +++ b/drivers/remoteproc/qcom_q6v5_adsp.c
>> @@ -717,7 +717,7 @@ static int adsp_probe(struct platform_device *pdev)
>>  		goto disable_pm;
>>  
>>  	ret = qcom_q6v5_init(&adsp->q6v5, pdev, rproc, desc->crash_reason_smem,
>> -			     desc->load_state, qcom_adsp_pil_handover);
>> +			     desc->load_state, false, qcom_adsp_pil_handover);
>>  	if (ret)
>>  		goto disable_pm;
>>  
>> diff --git a/drivers/remoteproc/qcom_q6v5_mss.c b/drivers/remoteproc/qcom_q6v5_mss.c
>> index 0c0199fb0e68..04e577541c8f 100644
>> --- a/drivers/remoteproc/qcom_q6v5_mss.c
>> +++ b/drivers/remoteproc/qcom_q6v5_mss.c
>> @@ -2156,7 +2156,7 @@ static int q6v5_probe(struct platform_device *pdev)
>>  	qproc->has_mba_logs = desc->has_mba_logs;
>>  
>>  	ret = qcom_q6v5_init(&qproc->q6v5, pdev, rproc, MPSS_CRASH_REASON_SMEM, "modem",
>> -			     qcom_msa_handover);
>> +			     false, qcom_msa_handover);
>>  	if (ret)
>>  		goto detach_proxy_pds;
>>  
>> diff --git a/drivers/remoteproc/qcom_q6v5_pas.c b/drivers/remoteproc/qcom_q6v5_pas.c
>> index 55a7da801183..99163e48a76a 100644
>> --- a/drivers/remoteproc/qcom_q6v5_pas.c
>> +++ b/drivers/remoteproc/qcom_q6v5_pas.c
>> @@ -35,6 +35,8 @@
>>  
>>  #define MAX_ASSIGN_COUNT 3
>>  
>> +#define EARLY_BOOT_RETRY_INTERVAL_MS 5000
>> +
>>  struct qcom_pas_data {
>>  	int crash_reason_smem;
>>  	const char *firmware_name;
>> @@ -58,6 +60,7 @@ struct qcom_pas_data {
>>  	int region_assign_count;
>>  	bool region_assign_shared;
>>  	int region_assign_vmid;
>> +	bool early_boot;
>>  };
>>  
>>  struct qcom_pas {
>> @@ -430,6 +433,51 @@ static unsigned long qcom_pas_panic(struct rproc *rproc)
>>  	return qcom_q6v5_panic(&pas->q6v5);
>>  }
>>  
>> +static int qcom_pas_attach(struct rproc *rproc)
>> +{
>> +	int ret;
>> +	struct qcom_pas *adsp = rproc->priv;
>> +	bool ready_state;
>> +	bool crash_state;
>> +
>> +	if (!adsp->q6v5.early_boot)
>> +		return -EINVAL;
>> +
>> +	ret = irq_get_irqchip_state(adsp->q6v5.fatal_irq,
>> +				    IRQCHIP_STATE_LINE_LEVEL, &crash_state);
>> +
>> +	if (crash_state) {
>> +		dev_err(adsp->dev, "Sub system has crashed before driver probe\n");
>> +		adsp->rproc->state = RPROC_CRASHED;
>> +		return -EINVAL;
>> +	}
>> +
>> +	ret = irq_get_irqchip_state(adsp->q6v5.ready_irq,
>> +				    IRQCHIP_STATE_LINE_LEVEL, &ready_state);
>> +
>> +	if (ready_state) {
>> +		dev_info(adsp->dev, "Sub system has boot-up before driver probe\n");
>> +		adsp->rproc->state = RPROC_DETACHED;
>> +	} else {
>> +		ret = wait_for_completion_timeout(&adsp->q6v5.subsys_booted,
>> +						  msecs_to_jiffies(EARLY_BOOT_RETRY_INTERVAL_MS));
>> +		if (!ret) {
>> +			dev_err(adsp->dev, "Timeout on waiting for subsystem interrupt\n");
>> +			return -ETIMEDOUT;
>> +		}
>> +	}
>> +
>> +	ret = qcom_q6v5_ping_subsystem(&adsp->q6v5);
>> +	if (ret) {
>> +		dev_err(adsp->dev, "Failed to ping subsystem, assuming device crashed\n");
>> +		rproc->state = RPROC_CRASHED;
>> +		return ret;
>> +	}
>> +
>> +	adsp->q6v5.running = true;
>> +	return ret;
>> +}
>> +
>>  static const struct rproc_ops qcom_pas_ops = {
>>  	.unprepare = qcom_pas_unprepare,
>>  	.start = qcom_pas_start,
>> @@ -438,6 +486,7 @@ static const struct rproc_ops qcom_pas_ops = {
>>  	.parse_fw = qcom_register_dump_segments,
>>  	.load = qcom_pas_load,
>>  	.panic = qcom_pas_panic,
>> +	.attach = qcom_pas_attach,
>>  };
>>  
>>  static const struct rproc_ops qcom_pas_minidump_ops = {
>> @@ -760,7 +809,7 @@ static int qcom_pas_probe(struct platform_device *pdev)
>>  	pas->proxy_pd_count = ret;
>>  
>>  	ret = qcom_q6v5_init(&pas->q6v5, pdev, rproc, desc->crash_reason_smem,
>> -			     desc->load_state, qcom_pas_handover);
>> +			     desc->load_state, desc->early_boot, qcom_pas_handover);
>>  	if (ret)
>>  		goto detach_proxy_pds;
>>  
>> @@ -774,6 +823,16 @@ static int qcom_pas_probe(struct platform_device *pdev)
>>  	}
>>  
>>  	qcom_add_ssr_subdev(rproc, &pas->ssr_subdev, desc->ssr_name);
>> +
>> +	if (pas->q6v5.early_boot) {
>> +		ret = qcom_q6v5_ping_subsystem_init(&pas->q6v5, pdev);
>> +		if (ret)
>> +			dev_err(&pdev->dev,
>> +				"Unable to find ping/pong bits, falling back to firmware load\n");
>> +		else
>> +			pas->rproc->state = RPROC_DETACHED;
>> +	}
>> +
>>  	ret = rproc_add(rproc);
>>  	if (ret)
>>  		goto remove_ssr_sysmon;
>>
>> -- 
>> 2.25.1
>>
>