Re: [PATCH v4 2/3] i3c: master: dw: Map CCC hardware errors to I3C M0/M2

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Undocumented behavioral change and silent bug fix
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commit 5afd5fbee8dc926110284bae98310b5970134131
Author: Adrian Ng Ho Yin <[email protected]>

i3c: master: dw: Map CCC hardware errors to I3C M0/M2

This commit updates the DesignWare I3C master driver to map specific
response queue errors to standard I3C error codes M0 and M2. It also returns
-EIO for address NACKs and introduces dw_i3c_ccc_map_err() to centralize
error mapping.

> diff --git a/drivers/i3c/master/dw-i3c-master.c b/drivers/i3c/master/dw-i3c-master.c
> index e659ede79fc03..27d2025fcf041 100644
> --- a/drivers/i3c/master/dw-i3c-master.c
> +++ b/drivers/i3c/master/dw-i3c-master.c

[ ... ]

> @@ -743,10 +760,7 @@ static int dw_i3c_ccc_set(struct dw_i3c_master *master,
>  
>  	ret = xfer->ret;
>  	cmd = &xfer->cmds[0];
> -	if (!ret)
> -		ccc->dests[0].payload.actual_len = cmd->rx_len;
> -	if (cmd->error == RESPONSE_ERROR_IBA_NACK)
> -		ccc->err = I3C_ERROR_M2;
> +	ccc->err = dw_i3c_ccc_map_err(cmd->error);

[Severity: Medium]
Is this an unrelated bug fix? The commit message mentions mapping hardware
errors to I3C M0/M2, but it does not mention removing the assignment of
actual_len from the transmit operation here.

>  
>  	return ret;
>  }

[ ... ]

> @@ -783,8 +799,10 @@ static int dw_i3c_ccc_get(struct dw_i3c_master *master, struct i3c_ccc_cmd *ccc)
>  		dw_i3c_master_dequeue_xfer(master, xfer);
>  
>  	ret = xfer->ret;
> -	if (xfer->cmds[0].error == RESPONSE_ERROR_IBA_NACK)
> -		ccc->err = I3C_ERROR_M2;
> +	cmd = &xfer->cmds[0];
> +	ccc->err = dw_i3c_ccc_map_err(cmd->error);
> +	if (!ret)
> +		ccc->dests[0].payload.actual_len = cmd->rx_len;

[Severity: Medium]
Does this silently add the actual_len assignment to the receive operation?

Since moving this assignment from dw_i3c_ccc_set() to dw_i3c_ccc_get() is
not documented in the commit message, should it be split into a separate
fix or explicitly explained?

>  
>  	return ret;
>  }

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Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=2

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