Re: [PATCH 7/8] i3c: master: Export i3c_master_enec_disec_locked()

On Tue, May 12, 2026 at 03:17:31PM +0300, Adrian Hunter wrote:
> The existing i3c_master_enec_locked() wrapper always treats a NACKed
> ENEC CCC as a failure (M2 error).  However, broadcasting ENEC to enable
> Hot-Join is legitimately useful even when no I3C devices are currently
> present on the bus, in which case the broadcast will be NACKed and
> should not be reported as an error.
>
> The underlying helper i3c_master_enec_disec_locked() already accepts a
> suppress_m2 flag that lets callers ignore such NACKs.  Expose it so that
> a subsequent patch enabling Hot-Join events can issue ENEC with M2
> suppression.
>
> Signed-off-by: Adrian Hunter <[email protected]>
> ---

Reviewed-by: Frank Li <[email protected]>

>  drivers/i3c/master.c       | 27 ++++++++++++++++++++++++---
>  include/linux/i3c/master.h |  2 ++
>  2 files changed, 26 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index 1eb157c8091d..db46cc12c7db 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -1121,9 +1121,29 @@ int i3c_master_entdaa_locked(struct i3c_master_controller *master)
>  }
>  EXPORT_SYMBOL_GPL(i3c_master_entdaa_locked);
>
> -static int i3c_master_enec_disec_locked(struct i3c_master_controller *master,
> -					u8 addr, bool enable, u8 evts,
> -					bool suppress_m2)
> +/**
> + * i3c_master_enec_disec_locked() - send an ENEC or DISEC CCC command
> + * @master: master used to send frames on the bus
> + * @addr: a valid I3C slave address or %I3C_BROADCAST_ADDR
> + * @enable: true to send ENEC, false to send DISEC
> + * @evts: events to enable or disable
> + * @suppress_m2: if true, treat an M2 (NACK) error from the CCC as success
> + *
> + * Send an ENEC or DISEC CCC command to enable or disable some or all events
> + * coming from a specific slave, or all devices if @addr is
> + * %I3C_BROADCAST_ADDR.
> + *
> + * When @suppress_m2 is true, a NACK of the broadcast (which can happen when
> + * no devices are present on the bus) is not reported as an error. This is
> + * useful for callers that want to configure event reporting unconditionally,
> + * regardless of whether any devices are currently on the bus.
> + *
> + * This function must be called with the bus lock held in write mode.
> + *
> + * Return: 0 in case of success, or a negative error code otherwise.
> + */
> +int i3c_master_enec_disec_locked(struct i3c_master_controller *master, u8 addr,
> +				 bool enable, u8 evts, bool suppress_m2)
>  {
>  	struct i3c_ccc_events *events;
>  	struct i3c_ccc_cmd_dest dest;
> @@ -1148,6 +1168,7 @@ static int i3c_master_enec_disec_locked(struct i3c_master_controller *master,
>
>  	return ret;
>  }
> +EXPORT_SYMBOL_GPL(i3c_master_enec_disec_locked);
>
>  /**
>   * i3c_master_disec_locked() - send a DISEC CCC command
> diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h
> index 8cdd7be505d3..e2c831fb5354 100644
> --- a/include/linux/i3c/master.h
> +++ b/include/linux/i3c/master.h
> @@ -607,6 +607,8 @@ int i3c_master_disec_locked(struct i3c_master_controller *master, u8 addr,
>  			    u8 evts);
>  int i3c_master_enec_locked(struct i3c_master_controller *master, u8 addr,
>  			   u8 evts);
> +int i3c_master_enec_disec_locked(struct i3c_master_controller *master, u8 addr,
> +				 bool enable, u8 evts, bool suppress_m2);
>  int i3c_master_entdaa_locked(struct i3c_master_controller *master);
>  int i3c_master_defslvs_locked(struct i3c_master_controller *master);
>
> --
> 2.51.0
>

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