Re: [PATCH] fpga: altera-cvp: allow interrupt to continue next time

From: Xu Yilun <yilun.xu@intel.com>
To: tien.sung.ang@intel.com
Cc: mdf@kernel.org, hao.wu@intel.com, trix@redhat.com,
	linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org,
	Dinh Nguyen <dinh.nguyen@intel.com>
Subject: Re: [PATCH] fpga: altera-cvp: allow interrupt to continue next time
Date: Sat, 28 May 2022 20:04:00 +0800	[thread overview]
Message-ID: <20220528120400.GA175058@yilunxu-OptiPlex-7050> (raw)
In-Reply-To: <20220518073844.2713722-1-tien.sung.ang@intel.com>

On Wed, May 18, 2022 at 03:38:44PM +0800, tien.sung.ang@intel.com wrote:
> From: Dinh Nguyen <dinh.nguyen@intel.com>
> 
> CFG_READY signal/bit may time-out due to firmware not responding
> within the given time-out. This time varies due to numerous
> factors like size of bitstream and others.
> This time-out error does not impact the result of the CvP
> previous transactions. The CvP driver shall then, respond with

Do you mean the reprogramming is successful even if you find the time
out in write_complete()? Then return 0 is better?

And could you specify what the time-out mean on write_init() phase?

Thanks,
Yilun

> EAGAIN instead Time out error.
> 
> Signed-off-by: Dinh Nguyen <dinh.nguyen@intel.com>
> Signed-off-by: Ang Tien Sung <tien.sung.ang@intel.com>
> ---
>  drivers/fpga/altera-cvp.c | 14 +++++++++++++-
>  1 file changed, 13 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/fpga/altera-cvp.c b/drivers/fpga/altera-cvp.c
> index 4ffb9da537d8..d74ff63c61e8 100644
> --- a/drivers/fpga/altera-cvp.c
> +++ b/drivers/fpga/altera-cvp.c
> @@ -309,10 +309,22 @@ static int altera_cvp_teardown(struct fpga_manager *mgr,
>  	/* STEP 15 - poll CVP_CONFIG_READY bit for 0 with 10us timeout */
>  	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY, 0,
>  				     conf->priv->poll_time_us);
> -	if (ret)
> +	if (ret) {
>  		dev_err(&mgr->dev, "CFG_RDY == 0 timeout\n");
> +		goto error_path;
> +	}
>  
>  	return ret;
> +
> +error_path:
> +	/* reset CVP_MODE and HIP_CLK_SEL bit */
> +	altera_read_config_dword(conf, VSE_CVP_MODE_CTRL, &val);
> +	val &= ~VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
> +	val &= ~VSE_CVP_MODE_CTRL_CVP_MODE;
> +	altera_write_config_dword(conf, VSE_CVP_MODE_CTRL, val);
> +
> +	return -EAGAIN;
> +
>  }
>  
>  static int altera_cvp_write_init(struct fpga_manager *mgr,
> -- 
> 2.25.1