Re: [PATCH] spi: atcspi200: validate data buswidth to fix FIELD_PREP build error

[Pei Xiao <xiaopei01@kylinos.cn>]

在 2026/2/23 14:36, CL Wang 写道:
> Hi Pei,
>
> Thanks for the patch to address the GCC compiler warning.
>
> While I understand that the SPI framework theoretically guarantees
> op->data.buswidth won't produce an out-of-bounds value here, I have
> some concerns regarding the proposed error handling.
>
> Using a direct return; inside atcspi_set_trans_ctl() creates a silent failure.
> Since the function returns void, the callers (atcspi_prepare_trans and
> atcspi_exec_mem_op) remain completely unaware of the error. They will blindly
> proceed with the transfer, leaving the hardware in an unconfigured or unknown
> state. Additionally, using a forced bitwise truncation could also lead to
> uncontrollable hardware behavior.
>
> A safer approach would be to either modify the function signatures to propagate
> the error (e.g., returning -EINVAL), or at least fall back to a safe default
> (like forcing width_code = 0 for standard 1-bit mode) along with
> a WARN_ON_ONCE().
>
> Since this requires a bit more structural adjustment in the driver, would you
> mind if I take this over and submit a proper fix? I will make sure to add a
> Suggested-by tag to acknowledge your effort in bringing this up.

please go ahead with the modifications, thank you!

Pei .

Thanks!

> Thanks again for catching this!
>
> Best regards,
> CL