Re: [PATCH v1 1/2] bus: mhi: core: Read serial number during pre-powerup phase

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Thu, Jul 15, 2021 at 05:27:55PM -0700, Bhaumik Bhatt wrote:
> In some cases, device may boot straight to the mission mode
> execution environment and skip the PBL transition or firmware
> load procedure. Serial number and OEM PK hash values would remain
> unpopulated in those scenarios. Move the reads for those to the
> power up preparation phase such that controllers always have them
> populated.
> 
> Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Thanks,
Mani

> ---
>  drivers/bus/mhi/core/boot.c | 17 +----------------
>  drivers/bus/mhi/core/init.c | 17 ++++++++++++++++-
>  2 files changed, 17 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c
> index 8100cf5..213307ab 100644
> --- a/drivers/bus/mhi/core/boot.c
> +++ b/drivers/bus/mhi/core/boot.c
> @@ -394,28 +394,13 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
>  	void *buf;
>  	dma_addr_t dma_addr;
>  	size_t size;
> -	int i, ret;
> +	int ret;
>  
>  	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
>  		dev_err(dev, "Device MHI is not in valid state\n");
>  		return;
>  	}
>  
> -	/* save hardware info from BHI */
> -	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_SERIALNU,
> -			   &mhi_cntrl->serial_number);
> -	if (ret)
> -		dev_err(dev, "Could not capture serial number via BHI\n");
> -
> -	for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) {
> -		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i),
> -				   &mhi_cntrl->oem_pk_hash[i]);
> -		if (ret) {
> -			dev_err(dev, "Could not capture OEM PK HASH via BHI\n");
> -			break;
> -		}
> -	}
> -
>  	/* wait for ready on pass through or any other execution environment */
>  	if (mhi_cntrl->ee != MHI_EE_EDL && mhi_cntrl->ee != MHI_EE_PBL)
>  		goto fw_load_ready_state;
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index aeb1e3c..8b4336e 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -1065,7 +1065,7 @@ int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
>  {
>  	struct device *dev = &mhi_cntrl->mhi_dev->dev;
>  	u32 bhi_off, bhie_off;
> -	int ret;
> +	int i, ret;
>  
>  	mutex_lock(&mhi_cntrl->pm_mutex);
>  
> @@ -1124,6 +1124,21 @@ int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
>  
>  	mutex_unlock(&mhi_cntrl->pm_mutex);
>  
> +	/* save hardware info from BHI */
> +	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_SERIALNU,
> +			   &mhi_cntrl->serial_number);
> +	if (ret)
> +		dev_err(dev, "Could not capture serial number via BHI\n");
> +
> +	for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) {
> +		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i),
> +				   &mhi_cntrl->oem_pk_hash[i]);
> +		if (ret) {
> +			dev_err(dev, "Could not capture OEM PK HASH via BHI\n");
> +			break;
> +		}
> +	}
> +
>  	return 0;
>  
>  error_reg_offset:
> -- 
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>