[PATCH 2/3] firmware: arm_ffa: Fix usage of partition info get count flag

[Jens Wiklander]

On Wed, Apr 19, 2023 at 11:54 AM Sudeep Holla <sudeep.holla at arm.com> wrote:
>
> Commit bb1be7498500 ("firmware: arm_ffa: Add v1.1 get_partition_info support")
> adds support to discovery the UUIDs of the partitions or just fetch the
> partition count using the PARTITION_INFO_GET_RETURN_COUNT_ONLY flag.
>
> However the commit doesn't handle the fact that the older version doesn't
> understand the flag and must be MBZ which results in firmware returning
> invalid parameter error. That results in the failure of the driver probe
> which is in correct.
>
> Limit the usage of the PARTITION_INFO_GET_RETURN_COUNT_ONLY flag for the
> versions above v1.0(i.e v1.1 and onwards) which fixes the issue.
>
> Fixes: bb1be7498500 ("firmware: arm_ffa: Add v1.1 get_partition_info support")
> Reported-by: Jens Wiklander <jens.wiklander at linaro.org>
> Reported-by: Marc Bonnici <marc.bonnici at arm.com>
> Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
> ---
>  drivers/firmware/arm_ffa/driver.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Tested-by: Jens Wiklander <jens.wiklander at linaro.org>
Reviewed-by: Jens Wiklander <jens.wiklander at linaro.org>

Thanks,
Jens

>
> diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c
> index fa85c64d3ded..4aced2e5b772 100644
> --- a/drivers/firmware/arm_ffa/driver.c
> +++ b/drivers/firmware/arm_ffa/driver.c
> @@ -193,7 +193,8 @@ __ffa_partition_info_get(u32 uuid0, u32 uuid1, u32 uuid2, u32 uuid3,
>         int idx, count, flags = 0, sz, buf_sz;
>         ffa_value_t partition_info;
>
> -       if (!buffer || !num_partitions) /* Just get the count for now */
> +       if (drv_info->version > FFA_VERSION_1_0 &&
> +           (!buffer || !num_partitions)) /* Just get the count for now */
>                 flags = PARTITION_INFO_GET_RETURN_COUNT_ONLY;
>
>         mutex_lock(&drv_info->rx_lock);
>
> --
> 2.40.0
>