Re: [PATCH v2 3/5] i3c: master: Move bus_init error suppression

[Frank Li]

On Thu, Mar 12, 2026 at 05:38:06PM +0100, Jorge Marques wrote:
> Prepares to fix improper Mx positive error propagation in later commits
> by handling Mx error codes where the i3c_ccc_cmd command is allocated.
> The CCC DISEC to broadcast address is invoked with
> i3c_master_enec_disec_locked() and yields error I3C_ERROR_M2 if there
> are no devices active on the bus. This is expected at the bus
> initialization stage, where it is not known yet that there are no active
> devices on the bus. Add bool suppress_m2 argument to
> i3c_master_enec_disec_locked() and update the call site at
> i3c_master_bus_init() with the exact corner case to not require
> propagating positive Mx error codes. Other call site should not suppress
> the error code, for example, if a driver requests to peripheral to
> disable events and the transfer is not acknowledged, this is an error
> and should not proceed.
>
> Signed-off-by: Jorge Marques <jorge.marques@xxxxxxxxxx>
> ---
Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
>  drivers/i3c/master.c | 23 +++++++++++++++--------
>  1 file changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> index d4f9e7df4adc5..bc1189afaed81 100644
> --- a/drivers/i3c/master.c
> +++ b/drivers/i3c/master.c
> @@ -1059,7 +1059,8 @@ 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)
> +					u8 addr, bool enable, u8 evts,
> +					bool suppress_m2)
>  {
>  	struct i3c_ccc_events *events;
>  	struct i3c_ccc_cmd_dest dest;
> @@ -1079,6 +1080,9 @@ static int i3c_master_enec_disec_locked(struct i3c_master_controller *master,
>  	ret = i3c_master_send_ccc_cmd_locked(master, &cmd);
>  	i3c_ccc_cmd_dest_cleanup(&dest);
>
> +	if (suppress_m2 && ret && cmd.err == I3C_ERROR_M2)
> +		ret = 0;
> +
>  	return ret;
>  }
>
> @@ -1099,7 +1103,7 @@ static int i3c_master_enec_disec_locked(struct i3c_master_controller *master,
>  int i3c_master_disec_locked(struct i3c_master_controller *master, u8 addr,
>  			    u8 evts)
>  {
> -	return i3c_master_enec_disec_locked(master, addr, false, evts);
> +	return i3c_master_enec_disec_locked(master, addr, false, evts, false);
>  }
>  EXPORT_SYMBOL_GPL(i3c_master_disec_locked);
>
> @@ -1120,7 +1124,7 @@ EXPORT_SYMBOL_GPL(i3c_master_disec_locked);
>  int i3c_master_enec_locked(struct i3c_master_controller *master, u8 addr,
>  			   u8 evts)
>  {
> -	return i3c_master_enec_disec_locked(master, addr, true, evts);
> +	return i3c_master_enec_disec_locked(master, addr, true, evts, false);
>  }
>  EXPORT_SYMBOL_GPL(i3c_master_enec_locked);
>
> @@ -2108,11 +2112,14 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
>  			goto err_bus_cleanup;
>  	}
>
> -	/* Disable all slave events before starting DAA. */
> -	ret = i3c_master_disec_locked(master, I3C_BROADCAST_ADDR,
> -				      I3C_CCC_EVENT_SIR | I3C_CCC_EVENT_MR |
> -				      I3C_CCC_EVENT_HJ);
> -	if (ret && ret != I3C_ERROR_M2)
> +	/*
> +	 * Disable all slave events before starting DAA. When no active device
> +	 * is on the bus, returns Mx error code M2, this error is ignored.
> +	 */
> +	ret = i3c_master_enec_disec_locked(master, I3C_BROADCAST_ADDR, false,
> +					   I3C_CCC_EVENT_SIR | I3C_CCC_EVENT_MR |
> +					   I3C_CCC_EVENT_HJ, true);
> +	if (ret)
>  		goto err_bus_cleanup;
>
>  	/*
>
> --
> 2.51.1
>