Re: [PATCH v3 09/12] fpga: dfl: afu: add STP (SignalTap) support

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Jul 23, 2019 at 12:51:32PM +0800, Wu Hao wrote:
> STP (SignalTap) is one of the private features under the port for
> debugging. This patch adds private feature driver support for it
> to allow userspace applications to mmap related mmio region and
> provide STP service.
> 
> Signed-off-by: Xu Yilun <yilun.xu@intel.com>
> Signed-off-by: Wu Hao <hao.wu@intel.com>
> Acked-by: Moritz Fischer <mdf@kernel.org>
> Acked-by: Alan Tull <atull@kernel.org>
> Signed-off-by: Moritz Fischer <mdf@kernel.org>
> ---
>  drivers/fpga/dfl-afu-main.c | 34 ++++++++++++++++++++++++++++++++++
>  1 file changed, 34 insertions(+)
> 
> diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
> index 15dd4cb..395f96e 100644
> --- a/drivers/fpga/dfl-afu-main.c
> +++ b/drivers/fpga/dfl-afu-main.c
> @@ -514,6 +514,36 @@ static void port_afu_uinit(struct platform_device *pdev,
>  	.uinit = port_afu_uinit,
>  };
>  
> +static int port_stp_init(struct platform_device *pdev,
> +			 struct dfl_feature *feature)
> +{
> +	struct resource *res = &pdev->resource[feature->resource_index];
> +
> +	dev_dbg(&pdev->dev, "PORT STP Init.\n");

ftrace is your friend, no need to do a lot of "look I am here!"
messages.

> +
> +	return afu_mmio_region_add(dev_get_platdata(&pdev->dev),
> +				   DFL_PORT_REGION_INDEX_STP,
> +				   resource_size(res), res->start,
> +				   DFL_PORT_REGION_MMAP | DFL_PORT_REGION_READ |
> +				   DFL_PORT_REGION_WRITE);
> +}
> +
> +static void port_stp_uinit(struct platform_device *pdev,
> +			   struct dfl_feature *feature)
> +{
> +	dev_dbg(&pdev->dev, "PORT STP UInit.\n");

Same here.

Why have this function at all if it does not do anything?


thanks,

greg k-h