Subject: Re: [PATCH net-next v4 3/7] net: ftgmac100: Add reset toggling for Aspeed SOCs

From: Simon Horman <[email-masked]>
Date: Mon, 9 Dec 2024 16:49:46 +0000

On Thu, Dec 05, 2024 at 03:20:44PM +0800, Jacky Chou wrote:
> Toggle the SCU reset before hardware initialization.
> 
> Signed-off-by: Jacky Chou <[email-masked]>
> ---
>  drivers/net/ethernet/faraday/ftgmac100.c | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
> index 17ec35e75a65..96c1eee547c4 100644
> --- a/drivers/net/ethernet/faraday/ftgmac100.c
> +++ b/drivers/net/ethernet/faraday/ftgmac100.c
> @@ -9,6 +9,7 @@
>  #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
>  
>  #include <linux/clk.h>
> +#include <linux/reset.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/etherdevice.h>
>  #include <linux/ethtool.h>
> @@ -98,6 +99,7 @@ struct ftgmac100 {
>  	struct work_struct reset_task;
>  	struct mii_bus *mii_bus;
>  	struct clk *clk;
> +	struct reset_control *rst;
>  
>  	/* AST2500/AST2600 RMII ref clock gate */
>  	struct clk *rclk;
> @@ -1979,6 +1981,22 @@ static int ftgmac100_probe(struct platform_device *pdev)
>  				  priv->base + FTGMAC100_OFFSET_TM);
>  	}
>  
> +	priv->rst = devm_reset_control_get_optional_exclusive(priv->dev, NULL);
> +	if (IS_ERR(priv->rst))
> +		goto err_register_netdev;

Hi Jacky,

The goto on the line above will result in this function returning err.
However, it seems that err is set to 0 here.
And perhaps it should be set to PTR_ERR(priv->rst).

Flagged by Smatch.

> +
> +	err = reset_control_assert(priv->rst);
> +	if (err) {
> +		dev_err(priv->dev, "Failed to reset mac (%d)\n", err);
> +		goto err_register_netdev;
> +	}
> +	usleep_range(10000, 20000);
> +	err = reset_control_deassert(priv->rst);
> +	if (err) {
> +		dev_err(priv->dev, "Failed to deassert mac reset (%d)\n", err);
> +		goto err_register_netdev;
> +	}
> +
>  	/* Default ring sizes */
>  	priv->rx_q_entries = priv->new_rx_q_entries = DEF_RX_QUEUE_ENTRIES;
>  	priv->tx_q_entries = priv->new_tx_q_entries = DEF_TX_QUEUE_ENTRIES;
> -- 
> 2.25.1
> 
>