Re: [PATCH v3] tpm: Do not remap from ACPI resouces again for Pluton TPM

[Jarkko Sakkinen]

On Mon Jul 10, 2023 at 11:27 PM EEST, Valentin David wrote:
> For Pluton TPM devices, it was assumed that there was no ACPI memory
> regions. This is not true for ASUS ROG Ally. ACPI advertises
> 0xfd500000-0xfd5fffff.
>
> Since remapping is already done in `crb_map_pluton`, remapping again
> in `crb_map_io` causes EBUSY error:
> ```
> [    3.510453] tpm_crb MSFT0101:00: can't request region for resource [mem 0xfd500000-0xfd5fffff]
> [    3.510463] tpm_crb: probe of MSFT0101:00 failed with error -16
> ```
>
> Fixes: 4d2732882703 ("tpm_crb: Add support for CRB devices based on Pluton")
>
> Signed-off-by: Valentin David <valentin.david@xxxxxxxxx>
> ---
> v3: Add fixes tag
> ---
>  drivers/char/tpm/tpm_crb.c | 19 +++++++++++--------
>  1 file changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index d43a0d7b97a8..1a5d09b18513 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -563,15 +563,18 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
>  	u32 rsp_size;
>  	int ret;
>  
> -	INIT_LIST_HEAD(&acpi_resource_list);
> -	ret = acpi_dev_get_resources(device, &acpi_resource_list,
> -				     crb_check_resource, iores_array);
> -	if (ret < 0)
> -		return ret;
> -	acpi_dev_free_resource_list(&acpi_resource_list);
> -
> -	/* Pluton doesn't appear to define ACPI memory regions */
> +	/*
> +	 * Pluton sometimes does not define ACPI memory regions.
> +	 * Mapping is then done in crb_map_pluton
> +	 */
>  	if (priv->sm != ACPI_TPM2_COMMAND_BUFFER_WITH_PLUTON) {
> +		INIT_LIST_HEAD(&acpi_resource_list);
> +		ret = acpi_dev_get_resources(device, &acpi_resource_list,
> +					     crb_check_resource, iores_array);
> +		if (ret < 0)
> +			return ret;
> +		acpi_dev_free_resource_list(&acpi_resource_list);
> +
>  		if (resource_type(iores_array) != IORESOURCE_MEM) {
>  			dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n");
>  			return -EINVAL;
> -- 
> 2.41.0

Reviewed-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx>

BR, Jarkko