Re: [PATCH] bus: mhi: host: Add session ID to MHI controller

[Manivannan Sadhasivam]

On Mon, Oct 10, 2022 at 12:41:10PM +0800, Qiang Yu wrote:
> Session ID to be used during BHI transfers to recognize a
> particular session are currently not being stored in the MHI
> controller structure. Store them to allow for tracking and other
> future usage.
> 
> Signed-off-by: Qiang Yu <quic_qianyu@xxxxxxxxxxx>

Who/what is going to use this session id?

Thanks,
Mani

> ---
>  drivers/bus/mhi/host/boot.c | 8 ++++----
>  include/linux/mhi.h         | 1 +
>  2 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
> index 26d0edd..5bed8b51 100644
> --- a/drivers/bus/mhi/host/boot.c
> +++ b/drivers/bus/mhi/host/boot.c
> @@ -231,7 +231,7 @@ static int mhi_fw_load_bhi(struct mhi_controller *mhi_cntrl,
>  			   dma_addr_t dma_addr,
>  			   size_t size)
>  {
> -	u32 tx_status, val, session_id;
> +	u32 tx_status, val;
>  	int i, ret;
>  	void __iomem *base = mhi_cntrl->bhi;
>  	rwlock_t *pm_lock = &mhi_cntrl->pm_lock;
> @@ -253,16 +253,16 @@ static int mhi_fw_load_bhi(struct mhi_controller *mhi_cntrl,
>  		goto invalid_pm_state;
>  	}
>  
> -	session_id = MHI_RANDOM_U32_NONZERO(BHI_TXDB_SEQNUM_BMSK);
> +	mhi_cntrl->session_id = MHI_RANDOM_U32_NONZERO(BHI_TXDB_SEQNUM_BMSK);
>  	dev_dbg(dev, "Starting image download via BHI. Session ID: %u\n",
> -		session_id);
> +		mhi_cntrl->session_id);
>  	mhi_write_reg(mhi_cntrl, base, BHI_STATUS, 0);
>  	mhi_write_reg(mhi_cntrl, base, BHI_IMGADDR_HIGH,
>  		      upper_32_bits(dma_addr));
>  	mhi_write_reg(mhi_cntrl, base, BHI_IMGADDR_LOW,
>  		      lower_32_bits(dma_addr));
>  	mhi_write_reg(mhi_cntrl, base, BHI_IMGSIZE, size);
> -	mhi_write_reg(mhi_cntrl, base, BHI_IMGTXDB, session_id);
> +	mhi_write_reg(mhi_cntrl, base, BHI_IMGTXDB, mhi_cntrl->session_id);
>  	read_unlock_bh(pm_lock);
>  
>  	/* Wait for the image download to complete */
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
> index a5441ad..8b3c934 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -405,6 +405,7 @@ struct mhi_controller {
>  	u32 minor_version;
>  	u32 serial_number;
>  	u32 oem_pk_hash[MHI_MAX_OEM_PK_HASH_SEGMENTS];
> +	u32 session_id;
>  
>  	struct mhi_event *mhi_event;
>  	struct mhi_cmd *mhi_cmd;
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 
> 

-- 
மணிவண்ணன் சதாசிவம்