Subject: Re: [PATCH v3] ath10k: Don't always treat modem stop events as crashes

From: Youghandhar Chintala <[email-masked]>
Date: Fri, 24 Sep 2021 18:13:48 +0530

I pulled the latest patch changes and tested them on SC7180. Which works 
as expected.
Do not see this error message during reboot and can be seen while doing 
SSR.

Tested-By: Youghandhar Chintala <[email-masked]>

On 2021-09-23 05:03, Stephen Boyd wrote:
> When rebooting on sc7180 Trogdor devices I see the following crash from
> the wifi driver.
> 
>  ath10k_snoc 18800000.wifi: firmware crashed! (guid
> 83493570-29a2-4e98-a83e-70048c47669c)
> 
> This is because a modem stop event looks just like a firmware crash to
> the driver, the qmi connection is closed in both cases. Use the qcom 
> ssr
> notifier block to stop treating the qmi connection close event as a
> firmware crash signal when the modem hasn't actually crashed. See
> ath10k_qmi_event_server_exit() for more details.
> 
> This silences the crash message seen during every reboot.
> 
> Fixes: 3f14b73c3843 ("ath10k: Enable MSA region dump support for 
> WCN3990")
> Cc: Youghandhar Chintala <[email-masked]>
> Cc: Abhishek Kumar <[email-masked]>
> Cc: Steev Klimaszewski <[email-masked]>
> Cc: Matthias Kaehlcke <[email-masked]>
> Cc: Rakesh Pillai <[email-masked]>
> Signed-off-by: Stephen Boyd <[email-masked]>
> ---
> 
> Changes since v2
> (https://lore.kernel.org/r/[email-masked]):
>  * Use a new bit instead of overloading unregistering
> 
> Changes since v1
> (https://lore.kernel.org/r/[email-masked]):
>  * Push error message into function instead of checking at callsite
> 
>  drivers/net/wireless/ath/ath10k/qmi.c  |  3 +-
>  drivers/net/wireless/ath/ath10k/snoc.c | 77 ++++++++++++++++++++++++++
>  drivers/net/wireless/ath/ath10k/snoc.h |  5 ++
>  3 files changed, 84 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/ath/ath10k/qmi.c
> b/drivers/net/wireless/ath/ath10k/qmi.c
> index 07e478f9a808..80fcb917fe4e 100644
> --- a/drivers/net/wireless/ath/ath10k/qmi.c
> +++ b/drivers/net/wireless/ath/ath10k/qmi.c
> @@ -864,7 +864,8 @@ static void ath10k_qmi_event_server_exit(struct
> ath10k_qmi *qmi)
> 
>  	ath10k_qmi_remove_msa_permission(qmi);
>  	ath10k_core_free_board_files(ar);
> -	if (!test_bit(ATH10K_SNOC_FLAG_UNREGISTERING, &ar_snoc->flags))
> +	if (!test_bit(ATH10K_SNOC_FLAG_UNREGISTERING, &ar_snoc->flags) &&
> +	    !test_bit(ATH10K_SNOC_FLAG_MODEM_STOPPED, &ar_snoc->flags))
>  		ath10k_snoc_fw_crashed_dump(ar);
> 
>  	ath10k_snoc_fw_indication(ar, ATH10K_QMI_EVENT_FW_DOWN_IND);
> diff --git a/drivers/net/wireless/ath/ath10k/snoc.c
> b/drivers/net/wireless/ath/ath10k/snoc.c
> index ea00fbb15601..9513ab696fff 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.c
> +++ b/drivers/net/wireless/ath/ath10k/snoc.c
> @@ -12,6 +12,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/property.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/remoteproc/qcom_rproc.h>
>  #include <linux/of_address.h>
>  #include <linux/iommu.h>
> 
> @@ -1477,6 +1478,74 @@ void ath10k_snoc_fw_crashed_dump(struct ath10k 
> *ar)
>  	mutex_unlock(&ar->dump_mutex);
>  }
> 
> +static int ath10k_snoc_modem_notify(struct notifier_block *nb,
> unsigned long action,
> +				    void *data)
> +{
> +	struct ath10k_snoc *ar_snoc = container_of(nb, struct ath10k_snoc, 
> nb);
> +	struct ath10k *ar = ar_snoc->ar;
> +	struct qcom_ssr_notify_data *notify_data = data;
> +
> +	switch (action) {
> +	case QCOM_SSR_BEFORE_POWERUP:
> +		ath10k_dbg(ar, ATH10K_DBG_SNOC, "received modem starting event\n");
> +		clear_bit(ATH10K_SNOC_FLAG_MODEM_STOPPED, &ar_snoc->flags);
> +		break;
> +
> +	case QCOM_SSR_AFTER_POWERUP:
> +		ath10k_dbg(ar, ATH10K_DBG_SNOC, "received modem running event\n");
> +		break;
> +
> +	case QCOM_SSR_BEFORE_SHUTDOWN:
> +		ath10k_dbg(ar, ATH10K_DBG_SNOC, "received modem %s event\n",
> +			   notify_data->crashed ? "crashed" : "stopping");
> +		if (!notify_data->crashed)
> +			set_bit(ATH10K_SNOC_FLAG_MODEM_STOPPED, &ar_snoc->flags);
> +		else
> +			clear_bit(ATH10K_SNOC_FLAG_MODEM_STOPPED, &ar_snoc->flags);
> +		break;
> +
> +	case QCOM_SSR_AFTER_SHUTDOWN:
> +		ath10k_dbg(ar, ATH10K_DBG_SNOC, "received modem offline event\n");
> +		break;
> +
> +	default:
> +		ath10k_err(ar, "received unrecognized event %lu\n", action);
> +		break;
> +	}
> +
> +	return NOTIFY_OK;
> +}
> +
> +static int ath10k_modem_init(struct ath10k *ar)
> +{
> +	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
> +	void *notifier;
> +	int ret;
> +
> +	ar_snoc->nb.notifier_call = ath10k_snoc_modem_notify;
> +
> +	notifier = qcom_register_ssr_notifier("mpss", &ar_snoc->nb);
> +	if (IS_ERR(notifier)) {
> +		ret = PTR_ERR(notifier);
> +		ath10k_err(ar, "failed to initialize modem notifier: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ar_snoc->notifier = notifier;
> +
> +	return 0;
> +}
> +
> +static void ath10k_modem_deinit(struct ath10k *ar)
> +{
> +	int ret;
> +	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
> +
> +	ret = qcom_unregister_ssr_notifier(ar_snoc->notifier, &ar_snoc->nb);
> +	if (ret)
> +		ath10k_err(ar, "error %d unregistering notifier\n", ret);
> +}
> +
>  static int ath10k_setup_msa_resources(struct ath10k *ar, u32 msa_size)
>  {
>  	struct device *dev = ar->dev;
> @@ -1740,10 +1809,17 @@ static int ath10k_snoc_probe(struct
> platform_device *pdev)
>  		goto err_fw_deinit;
>  	}
> 
> +	ret = ath10k_modem_init(ar);
> +	if (ret)
> +		goto err_qmi_deinit;
> +
>  	ath10k_dbg(ar, ATH10K_DBG_SNOC, "snoc probe\n");
> 
>  	return 0;
> 
> +err_qmi_deinit:
> +	ath10k_qmi_deinit(ar);
> +
>  err_fw_deinit:
>  	ath10k_fw_deinit(ar);
> 
> @@ -1771,6 +1847,7 @@ static int ath10k_snoc_free_resources(struct 
> ath10k *ar)
>  	ath10k_fw_deinit(ar);
>  	ath10k_snoc_free_irq(ar);
>  	ath10k_snoc_release_resource(ar);
> +	ath10k_modem_deinit(ar);
>  	ath10k_qmi_deinit(ar);
>  	ath10k_core_destroy(ar);
> 
> diff --git a/drivers/net/wireless/ath/ath10k/snoc.h
> b/drivers/net/wireless/ath/ath10k/snoc.h
> index 5095d1893681..d4bce1707696 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.h
> +++ b/drivers/net/wireless/ath/ath10k/snoc.h
> @@ -6,6 +6,8 @@
>  #ifndef _SNOC_H_
>  #define _SNOC_H_
> 
> +#include <linux/notifier.h>
> +
>  #include "hw.h"
>  #include "ce.h"
>  #include "qmi.h"
> @@ -45,6 +47,7 @@ struct ath10k_snoc_ce_irq {
>  enum ath10k_snoc_flags {
>  	ATH10K_SNOC_FLAG_REGISTERED,
>  	ATH10K_SNOC_FLAG_UNREGISTERING,
> +	ATH10K_SNOC_FLAG_MODEM_STOPPED,
>  	ATH10K_SNOC_FLAG_RECOVERY,
>  	ATH10K_SNOC_FLAG_8BIT_HOST_CAP_QUIRK,
>  };
> @@ -75,6 +78,8 @@ struct ath10k_snoc {
>  	struct clk_bulk_data *clks;
>  	size_t num_clks;
>  	struct ath10k_qmi *qmi;
> +	struct notifier_block nb;
> +	void *notifier;
>  	unsigned long flags;
>  	bool xo_cal_supported;
>  	u32 xo_cal_data;
> 
> base-commit: e4e737bb5c170df6135a127739a9e6148ee3da82

Regards,
Youghandhar
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