[PATCH v2] drm/amd/pm: Ignore initial value in smu response register

[Lazar, Lijo]

On 7/8/2024 7:01 PM, Danijel Slivka wrote:
> Why:
> If the reg mmMP1_SMN_C2PMSG_90 is being written to during amdgpu driver
> load or driver unload, subsequent amdgpu driver load will fail at
> smu_hw_init. The default of mmMP1_SMN_C2PMSG_90 register at a clean
> environment is 0x1 and if value differs from expected, amdgpu driver
> load will fail.
> 
> How to fix:
> Ignore the initial value in smu response register before the first smu
> message is sent,if smc in SMU_FW_INIT state, just proceed further to
> send the message. If register holds an unexpected value after smu message
> was sent set, smc_state to SMU_FW_HANG state and no further smu messages
> will be sent.
> 
> v2:
> Set SMU_FW_INIT state at the start of smu hw_init/resume.
> Check smc_fw_state before sending smu message if in hang state skip
> sending message.
> Set SMU_FW_HANG only in case unexpected value is detected
> 
> Signed-off-by: Danijel Slivka <danijel.slivka at amd.com>

Patch looks good to me

	Reviewed-by: Lijo Lazar <lijo.lazar at amd.com>

Copying Kenneth/Kevin as well.

Thanks,
Lijo

> ---
>  drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c     |  2 ++
>  drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h |  7 ++++
>  drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c        | 34 ++++++++++++++++---
>  3 files changed, 38 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> index d79bdb1e8cdf..fb8643d25d1b 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> @@ -1755,6 +1755,8 @@ static int smu_start_smc_engine(struct smu_context *smu)
>  	struct amdgpu_device *adev = smu->adev;
>  	int ret = 0;
>  
> +	smu->smc_fw_state = SMU_FW_INIT;
> +
>  	if (adev->firmware.load_type != AMDGPU_FW_LOAD_PSP) {
>  		if (amdgpu_ip_version(adev, MP1_HWIP, 0) < IP_VERSION(11, 0, 0)) {
>  			if (smu->ppt_funcs->load_microcode) {
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> index a34c802f52be..b44a185d07e8 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> +++ b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> @@ -495,6 +495,12 @@ struct stb_context {
>  	spinlock_t lock;
>  };
>  
> +enum smu_fw_status {
> +	SMU_FW_INIT = 0,
> +	SMU_FW_RUNTIME,
> +	SMU_FW_HANG,
> +};
> +
>  #define WORKLOAD_POLICY_MAX 7
>  
>  /*
> @@ -562,6 +568,7 @@ struct smu_context {
>  	uint32_t smc_fw_if_version;
>  	uint32_t smc_fw_version;
>  	uint32_t smc_fw_caps;
> +	uint8_t smc_fw_state;
>  
>  	bool uploading_custom_pp_table;
>  	bool dc_controlled_by_gpio;
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> index 5592fd825aa3..d7c983a1f3f5 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> @@ -315,11 +315,20 @@ int smu_cmn_send_msg_without_waiting(struct smu_context *smu,
>  	if (adev->no_hw_access)
>  		return 0;
>  
> -	reg = __smu_cmn_poll_stat(smu);
> -	res = __smu_cmn_reg2errno(smu, reg);
> -	if (reg == SMU_RESP_NONE ||
> -	    res == -EREMOTEIO)
> +	if (smu->smc_fw_state == SMU_FW_HANG) {
> +		dev_err(adev->dev, "SMU is in hanged state, failed to send smu message!\n");
>  		goto Out;
> +	}
> +
> +	if (smu->smc_fw_state == SMU_FW_INIT) {
> +		smu->smc_fw_state = SMU_FW_RUNTIME;
> +	} else {
> +		reg = __smu_cmn_poll_stat(smu);
> +		res = __smu_cmn_reg2errno(smu, reg);
> +		if (reg == SMU_RESP_NONE || res == -EREMOTEIO)
> +			goto Out;
> +	}
> +
>  	__smu_cmn_send_msg(smu, msg_index, param);
>  	res = 0;
>  Out:
> @@ -350,6 +359,9 @@ int smu_cmn_wait_for_response(struct smu_context *smu)
>  	reg = __smu_cmn_poll_stat(smu);
>  	res = __smu_cmn_reg2errno(smu, reg);
>  
> +	if (res == -EREMOTEIO)
> +		smu->smc_fw_state = SMU_FW_HANG;
> +
>  	if (unlikely(smu->adev->pm.smu_debug_mask & SMU_DEBUG_HALT_ON_ERROR) &&
>  	    res && (res != -ETIME)) {
>  		amdgpu_device_halt(smu->adev);
> @@ -418,6 +430,15 @@ int smu_cmn_send_smc_msg_with_param(struct smu_context *smu,
>  			goto Out;
>  	}
>  
> +	if (smu->smc_fw_state == SMU_FW_HANG) {
> +		dev_err(adev->dev, "SMU is in hanged state, failed to send smu message!\n");
> +		goto Out;
> +	} else if (smu->smc_fw_state == SMU_FW_INIT) {
> +		/* Ignore initial smu response register value */
> +		poll = false;
> +		smu->smc_fw_state = SMU_FW_RUNTIME;
> +	}
> +
>  	if (poll) {
>  		reg = __smu_cmn_poll_stat(smu);
>  		res = __smu_cmn_reg2errno(smu, reg);
> @@ -429,8 +450,11 @@ int smu_cmn_send_smc_msg_with_param(struct smu_context *smu,
>  	__smu_cmn_send_msg(smu, (uint16_t) index, param);
>  	reg = __smu_cmn_poll_stat(smu);
>  	res = __smu_cmn_reg2errno(smu, reg);
> -	if (res != 0)
> +	if (res != 0) {
> +		if (res == -EREMOTEIO)
> +			smu->smc_fw_state = SMU_FW_HANG;
>  		__smu_cmn_reg_print_error(smu, reg, index, param, msg);
> +	}
>  	if (read_arg) {
>  		smu_cmn_read_arg(smu, read_arg);
>  		dev_dbg(adev->dev, "smu send message: %s(%d) param: 0x%08x, resp: 0x%08x,\