[PATCH] fsi: aspeed: Reset master errors after CFAM reset

[Joel Stanley]

On Mon, 6 Mar 2023 at 22:53, Eddie James <eajames at linux.ibm.com> wrote:
>
> It has been observed that sometimes the FSI master will return all 0xffs
> after a CFAM has been taken out of reset, without presenting any error.
> Resetting the FSI master errors resolves the issue.

Eddie, you mentioned that Joachim was going to provide input on this
change. Did you hear from him?

Cheers,

Joel

>
> Signed-off-by: Eddie James <eajames at linux.ibm.com>
> ---
>  drivers/fsi/fsi-master-aspeed.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/fsi/fsi-master-aspeed.c b/drivers/fsi/fsi-master-aspeed.c
> index 7cec1772820d..5eccab175e86 100644
> --- a/drivers/fsi/fsi-master-aspeed.c
> +++ b/drivers/fsi/fsi-master-aspeed.c
> @@ -454,6 +454,8 @@ static ssize_t cfam_reset_store(struct device *dev, struct device_attribute *att
>         gpiod_set_value(aspeed->cfam_reset_gpio, 1);
>         usleep_range(900, 1000);
>         gpiod_set_value(aspeed->cfam_reset_gpio, 0);
> +       usleep_range(900, 1000);

Is the delay required? How did you arrive at this time?

> +       opb_writel(aspeed, ctrl_base + FSI_MRESP0, cpu_to_be32(FSI_MRESP_RST_ALL_MASTER));
>         mutex_unlock(&aspeed->lock);
>         trace_fsi_master_aspeed_cfam_reset(false);
>
> --
> 2.31.1
>