linux-kernel - Re: [PATCH v1 6/6] bus: mhi: core: Skip RDDM download for unknown execution environment

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Date:   Fri, 6 Nov 2020 11:08:19 +0530
From:   Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
To:     Bhaumik Bhatt <bbhatt@...eaurora.org>
Cc:     linux-arm-msm@...r.kernel.org, hemantk@...eaurora.org,
        jhugo@...eaurora.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 6/6] bus: mhi: core: Skip RDDM download for unknown
 execution environment

On Thu, Nov 05, 2020 at 04:34:29PM -0800, Bhaumik Bhatt wrote:
> If MHI is unable to determine the execution environment during
> the panic path, host must skip the RDDM download. This can happen
> if the BHI offset read or the BHI_EXECENV register read fails
> indicating that the underlying transport is unresponsive. Hence,
> there is no need to trigger an RDDM using SYSERR or request an
> SOC reset.
> 
> Suggested-by: Hemant Kumar <hemantk@...eaurora.org>
> Signed-off-by: Bhaumik Bhatt <bbhatt@...eaurora.org>
> ---
>  drivers/bus/mhi/core/boot.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c
> index 16244cc..40606e5 100644
> --- a/drivers/bus/mhi/core/boot.c
> +++ b/drivers/bus/mhi/core/boot.c
> @@ -92,6 +92,9 @@ static int __mhi_download_rddm_in_panic(struct mhi_controller *mhi_cntrl)
>  	 * image download completion.
>  	 */
>  	ee = mhi_get_exec_env(mhi_cntrl);
> +	if (ee == MHI_EE_MAX)
> +		goto error_exit_rddm;
> +
>  	if (ee != MHI_EE_RDDM) {
>  		dev_dbg(dev, "Trigger device into RDDM mode using SYS ERR\n");
>  		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_SYS_ERR);
> @@ -140,9 +143,11 @@ static int __mhi_download_rddm_in_panic(struct mhi_controller *mhi_cntrl)
>  	ret = mhi_read_reg(mhi_cntrl, base, BHIE_RXVECSTATUS_OFFS, &rx_status);
>  
>  	dev_err(dev, "Did not complete RDDM transfer\n");
> -	dev_err(dev, "Current EE: %s\n", TO_MHI_EXEC_STR(ee));
>  	dev_err(dev, "RXVEC_STATUS: 0x%x\n", rx_status);
>  
> +error_exit_rddm:
> +	dev_err(dev, "Current EE: %s\n", TO_MHI_EXEC_STR(ee));

Can this error message improved? It doesn't make much sense if error
path is taken.

Thanks,
Mani

> +
>  	return -EIO;
>  }
>  
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>