Re: [PATCH v3 1/2] i3c: dw-i3c-master: convert spinlock usage to scoped guards

[Frank Li <Frank.li@nxp.com>]

On Mon, Jan 26, 2026 at 01:42:22PM +0800, adrianhoyin.ng@altera.com wrote:
> From: Adrian Ng Ho Yin <adrianhoyin.ng@altera.com>
>
> Convert dw-i3c-master to use scoped spinlock guards in place of
> open-coded spin_lock_irqsave()/spin_unlock_irqrestore() pairs to ensure
> locks are always safely released on scope exit.
>
> Signed-off-by: Adrian Ng Ho Yin <adrianhoyin.ng@altera.com>
> ---
Reviewed-by: Frank Li <Frank.Li@nxp.com>
>  drivers/i3c/master/dw-i3c-master.c | 34 +++++++-----------------------
>  1 file changed, 8 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
> index 48af00659e19..ef8a38620e0e 100644
> --- a/drivers/i3c/master/dw-i3c-master.c
> +++ b/drivers/i3c/master/dw-i3c-master.c
> @@ -416,17 +416,14 @@ static void dw_i3c_master_start_xfer_locked(struct dw_i3c_master *master)
>  static void dw_i3c_master_enqueue_xfer(struct dw_i3c_master *master,
>  				       struct dw_i3c_xfer *xfer)
>  {
> -	unsigned long flags;
> -
>  	init_completion(&xfer->comp);
> -	spin_lock_irqsave(&master->xferqueue.lock, flags);
> +	guard(spinlock_irqsave)(&master->xferqueue.lock);
>  	if (master->xferqueue.cur) {
>  		list_add_tail(&xfer->node, &master->xferqueue.list);
>  	} else {
>  		master->xferqueue.cur = xfer;
>  		dw_i3c_master_start_xfer_locked(master);
>  	}
> -	spin_unlock_irqrestore(&master->xferqueue.lock, flags);
>  }
>
>  static void dw_i3c_master_dequeue_xfer_locked(struct dw_i3c_master *master,
> @@ -451,11 +448,8 @@ static void dw_i3c_master_dequeue_xfer_locked(struct dw_i3c_master *master,
>  static void dw_i3c_master_dequeue_xfer(struct dw_i3c_master *master,
>  				       struct dw_i3c_xfer *xfer)
>  {
> -	unsigned long flags;
> -
> -	spin_lock_irqsave(&master->xferqueue.lock, flags);
> +	guard(spinlock_irqsave)(&master->xferqueue.lock);
>  	dw_i3c_master_dequeue_xfer_locked(master, xfer);
> -	spin_unlock_irqrestore(&master->xferqueue.lock, flags);
>  }
>
>  static void dw_i3c_master_end_xfer_locked(struct dw_i3c_master *master, u32 isr)
> @@ -1194,15 +1188,13 @@ static int dw_i3c_master_request_ibi(struct i3c_dev_desc *dev,
>  	struct dw_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
>  	struct i3c_master_controller *m = i3c_dev_get_master(dev);
>  	struct dw_i3c_master *master = to_dw_i3c_master(m);
> -	unsigned long flags;
>
>  	data->ibi_pool = i3c_generic_ibi_alloc_pool(dev, req);
>  	if (IS_ERR(data->ibi_pool))
>  		return PTR_ERR(data->ibi_pool);
>
> -	spin_lock_irqsave(&master->devs_lock, flags);
> +	guard(spinlock_irqsave)(&master->devs_lock);
>  	master->devs[data->index].ibi_dev = dev;
> -	spin_unlock_irqrestore(&master->devs_lock, flags);
>
>  	return 0;
>  }
> @@ -1212,11 +1204,10 @@ static void dw_i3c_master_free_ibi(struct i3c_dev_desc *dev)
>  	struct dw_i3c_i2c_dev_data *data = i3c_dev_get_master_data(dev);
>  	struct i3c_master_controller *m = i3c_dev_get_master(dev);
>  	struct dw_i3c_master *master = to_dw_i3c_master(m);
> -	unsigned long flags;
>
> -	spin_lock_irqsave(&master->devs_lock, flags);
> -	master->devs[data->index].ibi_dev = NULL;
> -	spin_unlock_irqrestore(&master->devs_lock, flags);
> +	scoped_guard(spinlock_irqsave, &master->devs_lock) {
> +		master->devs[data->index].ibi_dev = NULL;
> +	}
>
>  	i3c_generic_ibi_free_pool(data->ibi_pool);
>  	data->ibi_pool = NULL;
> @@ -1243,13 +1234,12 @@ static void dw_i3c_master_set_sir_enabled(struct dw_i3c_master *master,
>  					  struct i3c_dev_desc *dev,
>  					  u8 idx, bool enable)
>  {
> -	unsigned long flags;
>  	u32 dat_entry, reg;
>  	bool global;
>
>  	dat_entry = DEV_ADDR_TABLE_LOC(master->datstartaddr, idx);
>
> -	spin_lock_irqsave(&master->devs_lock, flags);
> +	guard(spinlock_irqsave)(&master->devs_lock);
>  	reg = readl(master->regs + dat_entry);
>  	if (enable) {
>  		reg &= ~DEV_ADDR_TABLE_SIR_REJECT;
> @@ -1274,9 +1264,6 @@ static void dw_i3c_master_set_sir_enabled(struct dw_i3c_master *master,
>
>  	if (global)
>  		dw_i3c_master_enable_sir_signal(master, enable);
> -
> -
> -	spin_unlock_irqrestore(&master->devs_lock, flags);
>  }
>
>  static int dw_i3c_master_enable_hotjoin(struct i3c_master_controller *m)
> @@ -1377,7 +1364,6 @@ static void dw_i3c_master_handle_ibi_sir(struct dw_i3c_master *master,
>  	struct dw_i3c_i2c_dev_data *data;
>  	struct i3c_ibi_slot *slot;
>  	struct i3c_dev_desc *dev;
> -	unsigned long flags;
>  	u8 addr, len;
>  	int idx;
>
> @@ -1395,7 +1381,7 @@ static void dw_i3c_master_handle_ibi_sir(struct dw_i3c_master *master,
>  	 * a new platform op to validate it.
>  	 */
>
> -	spin_lock_irqsave(&master->devs_lock, flags);
> +	guard(spinlock_irqsave)(&master->devs_lock);
>  	idx = dw_i3c_master_get_addr_pos(master, addr);
>  	if (idx < 0) {
>  		dev_dbg_ratelimited(&master->base.dev,
> @@ -1431,14 +1417,10 @@ static void dw_i3c_master_handle_ibi_sir(struct dw_i3c_master *master,
>  	}
>  	i3c_master_queue_ibi(dev, slot);
>
> -	spin_unlock_irqrestore(&master->devs_lock, flags);
> -
>  	return;
>
>  err_drain:
>  	dw_i3c_master_drain_ibi_queue(master, len);
> -
> -	spin_unlock_irqrestore(&master->devs_lock, flags);
>  }
>
>  /* "ibis": referring to In-Band Interrupts, and not
> --
> 2.49.GIT
>