[PATCH v2 1/3] Subject: [PATCH] drm/mediatek/dp: Add tee client application for HDCP feature

[kernel test robot]

Hi mac.shen,

kernel test robot noticed the following build warnings:

[auto build test WARNING on drm-misc/drm-misc-next]
[also build test WARNING on pza/reset/next linus/master v6.8-rc3 next-20240205]
[cannot apply to pza/imx-drm/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/mac-shen/Subject-PATCH-drm-mediatek-dp-Add-tee-client-application-for-HDCP-feature/20240205-163727
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20240205055055.25340-2-mac.shen%40mediatek.com
patch subject: [PATCH v2 1/3] Subject: [PATCH] drm/mediatek/dp: Add tee client application for HDCP feature
config: arm64-defconfig (https://download.01.org/0day-ci/archive/20240205/202402052342.Y5awT1T2-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240205/202402052342.Y5awT1T2-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp at intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202402052342.Y5awT1T2-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/mediatek/tlc_dp_hdcp.c:34: warning: Function parameter or struct member 'dp_tee_priv' not described in 'dp_tee_op_send'
>> drivers/gpu/drm/mediatek/tlc_dp_hdcp.c:34: warning: Function parameter or struct member 'cmd_id' not described in 'dp_tee_op_send'


vim +34 drivers/gpu/drm/mediatek/tlc_dp_hdcp.c

    13	
    14	/*
    15	 * TA_FTPM_UUID: 99975014-3c7c-54ea-8487-a80d215ea92c
    16	 *
    17	 * Randomly generated, and must correspond to the GUID on the TA side.
    18	 * Defined here in the reference implementation:
    19	 * https://github.com/microsoft/ms-tpm-20-ref/blob/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/include/fTPM.h#L42
    20	 */
    21	static const uuid_t dp_ta_uuid =
    22		UUID_INIT(0x99975014, 0x3c7c, 0x54ea,
    23			  0x84, 0x87, 0xa8, 0x0d, 0x21, 0x5e, 0xa9, 0x2c);
    24	
    25	/**
    26	 * dp_tee_op_send() - send dp commands through the TEE shared memory.
    27	 * @len:	the number of bytes to send.
    28	 *
    29	 * Return:
    30	 *	In case of success, returns 0.
    31	 *	On failure, -errno
    32	 */
    33	static int dp_tee_op_send(struct dp_tee_private *dp_tee_priv, size_t len, u32 cmd_id)
  > 34	{
    35		int rc;
    36		u8 *temp_buf;
    37		struct tee_ioctl_invoke_arg transceive_args;
    38		struct tee_param command_params[4];
    39		struct tee_shm *shm = dp_tee_priv->shm;
    40	
    41		if (len > MAX_COMMAND_SIZE) {
    42			TLCERR("%s: len=%zd exceeds MAX_COMMAND_SIZE supported by dp TA\n", __func__, len);
    43			return -EIO;
    44		}
    45	
    46		memset(&transceive_args, 0, sizeof(transceive_args));
    47		memset(command_params, 0, sizeof(command_params));
    48		dp_tee_priv->resp_len = 0;
    49	
    50		/* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of dp TA */
    51		transceive_args = (struct tee_ioctl_invoke_arg) {
    52			.func = cmd_id,
    53			.session = dp_tee_priv->session,
    54			.num_params = 4,
    55		};
    56	
    57		/* Fill FTPM_OPTEE_TA_SUBMIT_COMMAND parameters */
    58		command_params[0] = (struct tee_param) {
    59			.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT,
    60			.u.memref = {
    61				.shm = shm,
    62				.size = len,
    63				.shm_offs = 0,
    64			},
    65		};
    66	
    67		command_params[1] = (struct tee_param) {
    68			.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT,
    69			.u.memref = {
    70				.shm = shm,
    71				.size = MAX_RESPONSE_SIZE,
    72				.shm_offs = MAX_COMMAND_SIZE,
    73			},
    74		};
    75	
    76		rc = tee_client_invoke_func(dp_tee_priv->ctx, &transceive_args, command_params);
    77		if (rc < 0 || transceive_args.ret != 0) {
    78			TLCERR("%s: invoke error: 0x%x\n", __func__, transceive_args.ret);
    79			return (rc < 0) ? rc : transceive_args.ret;
    80		}
    81	
    82		temp_buf = tee_shm_get_va(shm, command_params[1].u.memref.shm_offs);
    83		if (IS_ERR(temp_buf)) {
    84			TLCERR("%s: tee_shm_get_va failed for receive\n", __func__);
    85			return PTR_ERR(temp_buf);
    86		}
    87	
    88		/* Sanity checks look good, cache the response */
    89		memcpy(dp_tee_priv->resp_buf, temp_buf, MAX_RESPONSE_SIZE / 2);
    90		dp_tee_priv->resp_len = MAX_RESPONSE_SIZE / 2;
    91	
    92		return 0;
    93	}
    94	

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