Re: [PATCH V2] ptp: clockmatrix: Add Defer probe if firmware load fails

[Vincent Cheng <vscheng@gmail.com>]

On Sun, Jun 18, 2023 at 12:51:08AM +0000, Vincent Cheng wrote:
> 
> 
> -----Original Message-----
> From: Sarath Babu Naidu Gaddam <sarath.babu.naidu.gaddam@amd.com> 
> Sent: Wednesday, June 14, 2023 1:12 AM
> To: richardcochran@gmail.com; netdev@vger.kernel.org
> Cc: simon.horman@corigine.com; andrew@lunn.ch; linux-kernel@vger.kernel.org; Vincent Cheng <vincent.cheng.xh@renesas.com>; harini.katakam@amd.com; git@amd.com; sarath.babu.naidu.gaddam@amd.com
> Subject: [PATCH V2] ptp: clockmatrix: Add Defer probe if firmware load fails
> 
> Clock matrix driver can be probed before the rootfs containing firmware/initialization .bin is available. The current driver throws a warning and proceeds to execute probe even when firmware is not ready. Instead, defer probe and wait for the .bin file to be available.
> 
> Signed-off-by: Sarath Babu Naidu Gaddam <sarath.babu.naidu.gaddam@amd.com>

Reviewed-by: Vincent Cheng <vincent.cheng.xh@renesas.com>

> ---
> Changes in V2:
> 1) Added mutex_unlock(idtcm->lock); before returning EPROBE_DEFER.
> 2) Moved failure log after defer probe.
> ---
>  drivers/ptp/ptp_clockmatrix.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c index c9d451bf89e2..b3cb136257e3 100644
> --- a/drivers/ptp/ptp_clockmatrix.c
> +++ b/drivers/ptp/ptp_clockmatrix.c
> @@ -2424,8 +2424,13 @@ static int idtcm_probe(struct platform_device *pdev)
>  
>  	err = idtcm_load_firmware(idtcm, &pdev->dev);
>  
> -	if (err)
> +	if (err) {
> +		if (err == -ENOENT) {
> +			mutex_unlock(idtcm->lock);
> +			return -EPROBE_DEFER;
> +		}
>  		dev_warn(idtcm->dev, "loading firmware failed with %d", err);
> +	}
>  
>  	wait_for_chip_ready(idtcm);
>  
> --
> 2.25.1
>