Re: [PATCH] ath10k: Add support for WCN3990 firmware crash recovery

[Rakesh Pillai <pillair@codeaurora.org>]

Hi All,

I have raised the v2 for this, after rebasing this change qmi 
implementation patchset.

Thanks,
Rakesh Pillai.


On 2018-10-04 18:38, Rakesh Pillai wrote:
> From: Surabhi Vishnoi <svishnoi@codeaurora.org>
> 
> Whenever the WCN3990 firmware becomes unavailable,
> the host driver receives a FW down indication, post
> which all the direct hardware register access should
> be avoided, in order to prevent improper behavior in
> the host driver.
> 
> Set the crash_flush flag when the host driver receives
> a FW_DOWN_IND via qmi, in order to stop the untimely
> hardware register access. Also handle the case, where
> we need to do core register only for the first FW_READY
> indication, which is when we initialize the host driver.
> All the subsequent FW_READY indication will be received
> in subsystem recovery case and we only need to do the
> restart work. The state of driver is maintained using
> flags to distinguish between first and subsequent FW_READY
> indication received.
> 
> Tested HW: WCN3990
> Tested FW: WLAN.HL.2.0-01188-QCAHLSWMTPLZ-1
> 
> Signed-off-by: Surabhi Vishnoi <svishnoi@codeaurora.org>
> Signed-off-by: Rakesh Pillai <pillair@codeaurora.org>
> ---
>  drivers/net/wireless/ath/ath10k/core.c |  3 +++
>  drivers/net/wireless/ath/ath10k/core.h |  1 +
>  drivers/net/wireless/ath/ath10k/snoc.c | 39 
> +++++++++++++++++++++++++++++++---
>  drivers/net/wireless/ath/ath10k/snoc.h |  7 ++++++
>  4 files changed, 47 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath10k/core.c
> b/drivers/net/wireless/ath/ath10k/core.c
> index 9aa72da..9d0b351 100644
> --- a/drivers/net/wireless/ath/ath10k/core.c
> +++ b/drivers/net/wireless/ath/ath10k/core.c
> @@ -2184,6 +2184,8 @@ static void ath10k_core_restart(struct 
> work_struct *work)
>  	if (ret)
>  		ath10k_warn(ar, "failed to send firmware crash dump via devcoredump: 
> %d",
>  			    ret);
> +
> +	complete(&ar->driver_recovery);
>  }
> 
>  static void ath10k_core_set_coverage_class_work(struct work_struct 
> *work)
> @@ -3047,6 +3049,7 @@ struct ath10k *ath10k_core_create(size_t
> priv_size, struct device *dev,
>  	init_completion(&ar->scan.completed);
>  	init_completion(&ar->scan.on_channel);
>  	init_completion(&ar->target_suspend);
> +	init_completion(&ar->driver_recovery);
>  	init_completion(&ar->wow.wakeup_completed);
> 
>  	init_completion(&ar->install_key_done);
> diff --git a/drivers/net/wireless/ath/ath10k/core.h
> b/drivers/net/wireless/ath/ath10k/core.h
> index f66b46b..1376fc5 100644
> --- a/drivers/net/wireless/ath/ath10k/core.h
> +++ b/drivers/net/wireless/ath/ath10k/core.h
> @@ -962,6 +962,7 @@ struct ath10k {
>  	} hif;
> 
>  	struct completion target_suspend;
> +	struct completion driver_recovery;
> 
>  	const struct ath10k_hw_regs *regs;
>  	const struct ath10k_hw_ce_regs *hw_ce_regs;
> diff --git a/drivers/net/wireless/ath/ath10k/snoc.c
> b/drivers/net/wireless/ath/ath10k/snoc.c
> index bdffc4e..178840a 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.c
> +++ b/drivers/net/wireless/ath/ath10k/snoc.c
> @@ -918,7 +918,9 @@ static void ath10k_snoc_buffer_cleanup(struct 
> ath10k *ar)
> 
>  static void ath10k_snoc_hif_stop(struct ath10k *ar)
>  {
> -	ath10k_snoc_irq_disable(ar);
> +	if (!test_bit(ATH10K_FLAG_CRASH_FLUSH, &ar->dev_flags))
> +		ath10k_snoc_irq_disable(ar);
> +
>  	napi_synchronize(&ar->napi);
>  	napi_disable(&ar->napi);
>  	ath10k_snoc_buffer_cleanup(ar);
> @@ -927,10 +929,14 @@ static void ath10k_snoc_hif_stop(struct ath10k 
> *ar)
> 
>  static int ath10k_snoc_hif_start(struct ath10k *ar)
>  {
> +	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
> +
>  	napi_enable(&ar->napi);
>  	ath10k_snoc_irq_enable(ar);
>  	ath10k_snoc_rx_post(ar);
> 
> +	clear_bit(ATH10K_SNOC_FLAG_RECOVERY, &ar_snoc->flags);
> +
>  	ath10k_dbg(ar, ATH10K_DBG_BOOT, "boot hif start\n");
> 
>  	return 0;
> @@ -994,7 +1000,8 @@ static int ath10k_snoc_wlan_enable(struct ath10k 
> *ar)
> 
>  static void ath10k_snoc_wlan_disable(struct ath10k *ar)
>  {
> -	ath10k_qmi_wlan_disable(ar);
> +	if (!test_bit(ATH10K_FLAG_CRASH_FLUSH, &ar->dev_flags))
> +		ath10k_qmi_wlan_disable(ar);
>  }
> 
>  static void ath10k_snoc_hif_power_down(struct ath10k *ar)
> @@ -1091,6 +1098,11 @@ static int ath10k_snoc_napi_poll(struct
> napi_struct *ctx, int budget)
>  	struct ath10k *ar = container_of(ctx, struct ath10k, napi);
>  	int done = 0;
> 
> +	if (test_bit(ATH10K_FLAG_CRASH_FLUSH, &ar->dev_flags)) {
> +		napi_complete(ctx);
> +		return done;
> +	}
> +
>  	ath10k_ce_per_engine_service_any(ar);
>  	done = ath10k_htt_txrx_compl_task(ar, budget);
> 
> @@ -1187,17 +1199,29 @@ int ath10k_snoc_fw_indication(struct ath10k
> *ar, u64 type)
>  	struct ath10k_bus_params bus_params;
>  	int ret;
> 
> +	if (test_bit(ATH10K_SNOC_FLAG_UNREGISTERING, &ar_snoc->flags))
> +		return 0;
> +
>  	bus_params.chip_id = ar_snoc->target_info.soc_version;
> 
>  	switch (type) {
>  	case ATH10K_QMI_EVENT_FW_READY_IND:
> +		if (test_bit(ATH10K_SNOC_FLAG_REGISTERED, &ar_snoc->flags)) {
> +			queue_work(ar->workqueue, &ar->restart_work);
> +			break;
> +		}
> +
>  		ret = ath10k_core_register(ar, &bus_params);
>  		if (ret) {
> -			ath10k_err(ar, "failed to register driver core: %d\n",
> +			ath10k_err(ar, "Failed to register driver core: %d\n",
>  				   ret);
> +			return ret;
>  		}
> +		set_bit(ATH10K_SNOC_FLAG_REGISTERED, &ar_snoc->flags);
>  		break;
>  	case ATH10K_QMI_EVENT_FW_DOWN_IND:
> +		set_bit(ATH10K_SNOC_FLAG_RECOVERY, &ar_snoc->flags);
> +		set_bit(ATH10K_FLAG_CRASH_FLUSH, &ar->dev_flags);
>  		break;
>  	default:
>  		ath10k_err(ar, "invalid fw indication: %llx\n", type);
> @@ -1631,8 +1655,17 @@ static int ath10k_snoc_probe(struct
> platform_device *pdev)
>  static int ath10k_snoc_remove(struct platform_device *pdev)
>  {
>  	struct ath10k *ar = platform_get_drvdata(pdev);
> +	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
> 
>  	ath10k_dbg(ar, ATH10K_DBG_SNOC, "snoc remove\n");
> +
> +	reinit_completion(&ar->driver_recovery);
> +
> +	if (test_bit(ATH10K_SNOC_FLAG_RECOVERY, &ar_snoc->flags))
> +		wait_for_completion_timeout(&ar->driver_recovery, 3 * HZ);
> +
> +	set_bit(ATH10K_SNOC_FLAG_UNREGISTERING, &ar_snoc->flags);
> +
>  	ath10k_core_unregister(ar);
>  	ath10k_hw_power_off(ar);
>  	ath10k_snoc_free_irq(ar);
> diff --git a/drivers/net/wireless/ath/ath10k/snoc.h
> b/drivers/net/wireless/ath/ath10k/snoc.h
> index e1d2d66..3a44e30 100644
> --- a/drivers/net/wireless/ath/ath10k/snoc.h
> +++ b/drivers/net/wireless/ath/ath10k/snoc.h
> @@ -70,6 +70,12 @@ struct ath10k_wcn3990_clk_info {
>  	bool required;
>  };
> 
> +enum ath10k_snoc_flags {
> +	ATH10K_SNOC_FLAG_REGISTERED,
> +	ATH10K_SNOC_FLAG_UNREGISTERING,
> +	ATH10K_SNOC_FLAG_RECOVERY,
> +};
> +
>  struct ath10k_snoc {
>  	struct platform_device *dev;
>  	struct ath10k *ar;
> @@ -84,6 +90,7 @@ struct ath10k_snoc {
>  	struct ath10k_wcn3990_vreg_info *vreg;
>  	struct ath10k_wcn3990_clk_info *clk;
>  	struct ath10k_qmi *qmi;
> +	unsigned long int flags;
>  };
> 
>  static inline struct ath10k_snoc *ath10k_snoc_priv(struct ath10k *ar)