Re: [PATCH V2] firmware: imx: Skip return value check for some special SCU firmware APIs

From: Marco Felsch
Date: Wed Oct 09 2019 - 05:00:50 EST


Hi Anson,

On 19-10-07 09:15, Anson Huang wrote:
> The SCU firmware does NOT always have return value stored in message
> header's function element even the API has response data, those special
> APIs are defined as void function in SCU firmware, so they should be
> treated as return success always.
>
> Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> ---
> Changes since V1:
> - Use direct API check instead of calling another function to check.
> - This patch is based on https://patchwork.kernel.org/patch/11129553/
> ---
> drivers/firmware/imx/imx-scu.c | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/firmware/imx/imx-scu.c b/drivers/firmware/imx/imx-scu.c
> index 869be7a..03b43b7 100644
> --- a/drivers/firmware/imx/imx-scu.c
> +++ b/drivers/firmware/imx/imx-scu.c
> @@ -162,6 +162,7 @@ static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg)
> */
> int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
> {
> + uint8_t saved_svc, saved_func;
> struct imx_sc_rpc_msg *hdr;
> int ret;
>
> @@ -171,8 +172,11 @@ int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
> mutex_lock(&sc_ipc->lock);
> reinit_completion(&sc_ipc->done);
>
> - if (have_resp)
> + if (have_resp) {
> sc_ipc->msg = msg;
> + saved_svc = ((struct imx_sc_rpc_msg *)msg)->svc;

Why do we need to check the svc too?

> + saved_func = ((struct imx_sc_rpc_msg *)msg)->func;

Nitpick, should we call it requested_func/req_func?

Regards,
Marco

> + }
> sc_ipc->count = 0;
> ret = imx_scu_ipc_write(sc_ipc, msg);
> if (ret < 0) {
> @@ -191,6 +195,16 @@ int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
> /* response status is stored in hdr->func field */
> hdr = msg;
> ret = hdr->func;
> + /*
> + * Some special SCU firmware APIs do NOT have return value
> + * in hdr->func, but they do have response data, those special
> + * APIs are defined as void function in SCU firmware, so they
> + * should be treated as return success always.
> + */
> + if ((saved_svc == IMX_SC_RPC_SVC_MISC) &&
> + (saved_func == IMX_SC_MISC_FUNC_UNIQUE_ID ||
> + saved_func == IMX_SC_MISC_FUNC_GET_BUTTON_STATUS))
> + ret = 0;
> }
>
> out:
> --
> 2.7.4
>
>
>

--
Pengutronix e.K. | |
Industrial Linux Solutions | http://www.pengutronix.de/ |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |