Re: [PATCH v2] fpga: altera-hps2fpga: Fix reset control leak

[Xu Yilun]

On Sat, Nov 07, 2026 at 11:07:47PM +0800, Xiangwu Lai wrote:
> From: laixiangwu <laixiangwu@xxxxxxxxxxxxxxxxxxxx>
> 
> alt_fpga_bridge_probe() acquires the bridge reset control with
> of_reset_control_get_exclusive_by_index(), which is not
> device-managed. None of the probe error paths release it, and
> alt_fpga_bridge_remove() does not call reset_control_put() either,
> so the reset control reference leaks both on a failed probe and on
> every bind/unbind cycle.
> 
> Since the leaked exclusive reset remains acquired, rebinding the
> driver afterwards also fails with -EBUSY.
> 
> Use devm_reset_control_get_exclusive_by_index() so the reset control
> is released automatically when the driver is unbound or the probe
> fails.
> 
> Fixes: e5f8efa5c8bf ("ARM: socfpga: fpga bridge driver support")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Xiangwu Lai <laixiangwu@xxxxxxxxxxxxxxxxxxxx>

Reviewed-by: Xu Yilun <yilun.xu@xxxxxxxxx>

Applied to for-next, thanks

> ---
> Changes in v2:
> - Drop the enumeration of probe error path examples from the commit
>   message, as suggested by Xu Yilun.
> - Add Cc: stable@xxxxxxxxxxxxxxx for backporting.
> 
> Link: https://lore.kernel.org/r/20261103014240.1194-1-laixiangwu@xxxxxxxxxxxxxxxxxxxx
>  drivers/fpga/altera-hps2fpga.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/fpga/altera-hps2fpga.c b/drivers/fpga/altera-hps2fpga.c
> index f2f125068..6d9798bb9 100644
> --- a/drivers/fpga/altera-hps2fpga.c
> +++ b/drivers/fpga/altera-hps2fpga.c
> @@ -134,8 +134,7 @@ static int alt_fpga_bridge_probe(struct platform_device *pdev)
>  
>  	priv = (struct altera_hps2fpga_data *)device_get_match_data(dev);
>  
> -	priv->bridge_reset = of_reset_control_get_exclusive_by_index(dev->of_node,
> -								     0);
> +	priv->bridge_reset = devm_reset_control_get_exclusive_by_index(dev, 0);
>  	if (IS_ERR(priv->bridge_reset)) {
>  		dev_err(dev, "Could not get %s reset control\n", priv->name);
>  		return PTR_ERR(priv->bridge_reset);
> -- 
> 2.50.1.windows.1
> 
> 
> 
>