Re: [PATCH v3 2/2] i3c: dw: Simplify xfer cleanup with __free(kfree)

[Frank Li]

On Sat, Apr 04, 2026 at 06:32:31PM +0800, Felix Gu wrote:
> Convert dw-i3c-master to use __free(kfree) guards for struct dw_i3c_xfer
> allocations. This frees xfer objects automatically on scope exit, and
> removes the now-unused dw_i3c_master_free_xfer() helper.
>
> Signed-off-by: Felix Gu <ustc.gu@xxxxxxxxx>

Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> ---
>  drivers/i3c/master/dw-i3c-master.c | 33 +++++++--------------------------
>  1 file changed, 7 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
> index 2e31228b3809..41ef37115f8b 100644
> --- a/drivers/i3c/master/dw-i3c-master.c
> +++ b/drivers/i3c/master/dw-i3c-master.c
> @@ -394,11 +394,6 @@ dw_i3c_master_alloc_xfer(struct dw_i3c_master *master, unsigned int ncmds)
>  	return xfer;
>  }
>
> -static void dw_i3c_master_free_xfer(struct dw_i3c_xfer *xfer)
> -{
> -	kfree(xfer);
> -}
> -
>  static void dw_i3c_master_start_xfer_locked(struct dw_i3c_master *master)
>  {
>  	struct dw_i3c_xfer *xfer = master->xferqueue.cur;
> @@ -716,7 +711,6 @@ static void dw_i3c_master_bus_cleanup(struct i3c_master_controller *m)
>  static int dw_i3c_ccc_set(struct dw_i3c_master *master,
>  			  struct i3c_ccc_cmd *ccc)
>  {
> -	struct dw_i3c_xfer *xfer;
>  	struct dw_i3c_cmd *cmd;
>  	int ret, pos = 0;
>
> @@ -726,7 +720,7 @@ static int dw_i3c_ccc_set(struct dw_i3c_master *master,
>  			return pos;
>  	}
>
> -	xfer = dw_i3c_master_alloc_xfer(master, 1);
> +	struct dw_i3c_xfer *xfer __free(kfree) = dw_i3c_master_alloc_xfer(master, 1);
>  	if (!xfer)
>  		return -ENOMEM;
>
> @@ -751,14 +745,11 @@ static int dw_i3c_ccc_set(struct dw_i3c_master *master,
>  	if (xfer->cmds[0].error == RESPONSE_ERROR_IBA_NACK)
>  		ccc->err = I3C_ERROR_M2;
>
> -	dw_i3c_master_free_xfer(xfer);
> -
>  	return ret;
>  }
>
>  static int dw_i3c_ccc_get(struct dw_i3c_master *master, struct i3c_ccc_cmd *ccc)
>  {
> -	struct dw_i3c_xfer *xfer;
>  	struct dw_i3c_cmd *cmd;
>  	int ret, pos;
>
> @@ -766,7 +757,7 @@ static int dw_i3c_ccc_get(struct dw_i3c_master *master, struct i3c_ccc_cmd *ccc)
>  	if (pos < 0)
>  		return pos;
>
> -	xfer = dw_i3c_master_alloc_xfer(master, 1);
> +	struct dw_i3c_xfer *xfer __free(kfree) = dw_i3c_master_alloc_xfer(master, 1);
>  	if (!xfer)
>  		return -ENOMEM;
>
> @@ -791,7 +782,6 @@ static int dw_i3c_ccc_get(struct dw_i3c_master *master, struct i3c_ccc_cmd *ccc)
>  	ret = xfer->ret;
>  	if (xfer->cmds[0].error == RESPONSE_ERROR_IBA_NACK)
>  		ccc->err = I3C_ERROR_M2;
> -	dw_i3c_master_free_xfer(xfer);
>
>  	return ret;
>  }
> @@ -838,12 +828,15 @@ static int dw_i3c_master_send_ccc_cmd(struct i3c_master_controller *m,
>  static int dw_i3c_master_daa(struct i3c_master_controller *m)
>  {
>  	struct dw_i3c_master *master = to_dw_i3c_master(m);
> -	struct dw_i3c_xfer *xfer;
>  	struct dw_i3c_cmd *cmd;
>  	u32 olddevs, newdevs;
>  	u8 last_addr = 0;
>  	int ret, pos;
>
> +	struct dw_i3c_xfer *xfer __free(kfree) = dw_i3c_master_alloc_xfer(master, 1);
> +	if (!xfer)
> +		return -ENOMEM;
> +
>  	ret = pm_runtime_resume_and_get(master->dev);
>  	if (ret < 0) {
>  		dev_err(master->dev,
> @@ -877,15 +870,8 @@ static int dw_i3c_master_daa(struct i3c_master_controller *m)
>  		ret = 0;
>  	}
>
> -	xfer = dw_i3c_master_alloc_xfer(master, 1);
> -	if (!xfer) {
> -		ret = -ENOMEM;
> -		goto rpm_out;
> -	}
> -
>  	pos = dw_i3c_master_get_free_pos(master);
>  	if (pos < 0) {
> -		dw_i3c_master_free_xfer(xfer);
>  		ret = pos;
>  		goto rpm_out;
>  	}
> @@ -910,8 +896,6 @@ static int dw_i3c_master_daa(struct i3c_master_controller *m)
>  			i3c_master_add_i3c_dev_locked(m, master->devs[pos].addr);
>  	}
>
> -	dw_i3c_master_free_xfer(xfer);
> -
>  rpm_out:
>  	pm_runtime_put_autosuspend(master->dev);
>  	return ret;
> @@ -1083,7 +1067,6 @@ static int dw_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
>  	struct i3c_master_controller *m = i2c_dev_get_master(dev);
>  	struct dw_i3c_master *master = to_dw_i3c_master(m);
>  	unsigned int nrxwords = 0, ntxwords = 0;
> -	struct dw_i3c_xfer *xfer;
>  	int i, ret = 0;
>
>  	if (!i2c_nxfers)
> @@ -1103,7 +1086,7 @@ static int dw_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
>  	    nrxwords > master->caps.datafifodepth)
>  		return -EOPNOTSUPP;
>
> -	xfer = dw_i3c_master_alloc_xfer(master, i2c_nxfers);
> +	struct dw_i3c_xfer *xfer __free(kfree) = dw_i3c_master_alloc_xfer(master, i2c_nxfers);
>  	if (!xfer)
>  		return -ENOMEM;
>
> @@ -1112,7 +1095,6 @@ static int dw_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
>  		dev_err(master->dev,
>  			"<%s> cannot resume i3c bus master, err: %d\n",
>  			__func__, ret);
> -		dw_i3c_master_free_xfer(xfer);
>  		return ret;
>  	}
>
> @@ -1144,7 +1126,6 @@ static int dw_i3c_master_i2c_xfers(struct i2c_dev_desc *dev,
>  		dw_i3c_master_dequeue_xfer(master, xfer);
>
>  	ret = xfer->ret;
> -	dw_i3c_master_free_xfer(xfer);
>
>  	pm_runtime_put_autosuspend(master->dev);
>  	return ret;
>
> --
> 2.43.0
>