[Intel-gfx] [PATCH 5/5] drm/dp/mst: Provide better debugs for NAK replies

[Dhinakaran Pandiyan]

On Fri, 2018-09-28 at 21:04 +0300, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Decode the NAK reply fields to make it easier to parse the logs.
A lot better than seeing the error codes. 


0-day's found a conflicting definition that's missing an undef. With
that addressed, 
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> 
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/drm_dp_mst_topology.c | 65
> ++++++++++++++++++++++++++++++++++-
>  include/drm/drm_dp_helper.h           |  1 +
>  2 files changed, 65 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> b/drivers/gpu/drm/drm_dp_mst_topology.c
> index c0f754364cc7..1178c1655f9a 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -66,6 +66,64 @@ static bool drm_dp_validate_guid(struct
> drm_dp_mst_topology_mgr *mgr,
>  static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
>  static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
>  static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
> +
> +#define STR(x) [DP_ ## x] = #x
> +
> +static const char *drm_dp_mst_req_type_str(u8 req_type)
> +{
> +	static const char * const req_type_str[] = {
> +		STR(GET_MSG_TRANSACTION_VERSION),
> +		STR(LINK_ADDRESS),
> +		STR(CONNECTION_STATUS_NOTIFY),
> +		STR(ENUM_PATH_RESOURCES),
> +		STR(ALLOCATE_PAYLOAD),
> +		STR(QUERY_PAYLOAD),
> +		STR(RESOURCE_STATUS_NOTIFY),
> +		STR(CLEAR_PAYLOAD_ID_TABLE),
> +		STR(REMOTE_DPCD_READ),
> +		STR(REMOTE_DPCD_WRITE),
> +		STR(REMOTE_I2C_READ),
> +		STR(REMOTE_I2C_WRITE),
> +		STR(POWER_UP_PHY),
> +		STR(POWER_DOWN_PHY),
> +		STR(SINK_EVENT_NOTIFY),
> +		STR(QUERY_STREAM_ENC_STATUS),
> +	};
> +
> +	if (req_type >= ARRAY_SIZE(req_type_str) ||
> +	    !req_type_str[req_type])
> +		return "unknown";
> +
> +	return req_type_str[req_type];
> +}
> +
> +#undef STR
> +#define STR(x) [DP_NAK_ ## x] = #x
> +
> +static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
> +{
> +	static const char * const nak_reason_str[] = {
> +		STR(WRITE_FAILURE),
> +		STR(INVALID_READ),
> +		STR(CRC_FAILURE),
> +		STR(BAD_PARAM),
> +		STR(DEFER),
> +		STR(LINK_FAILURE),
> +		STR(NO_RESOURCES),
> +		STR(DPCD_FAIL),
> +		STR(I2C_NAK),
> +		STR(ALLOCATE_FAIL),
> +	};
> +
> +	if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
> +	    !nak_reason_str[nak_reason])
> +		return "unknown";
> +
> +	return nak_reason_str[nak_reason];
> +}
> +
> +#undef STR
> +
>  /* sideband msg handling */
>  static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t
> num_nibbles)
>  {
> @@ -2349,7 +2407,12 @@ static int drm_dp_mst_handle_down_rep(struct
> drm_dp_mst_topology_mgr *mgr)
>  
>  		drm_dp_sideband_parse_reply(&mgr->down_rep_recv,
> &txmsg->reply);
>  		if (txmsg->reply.reply_type == DP_REPLY_NAK) {
> -			DRM_DEBUG_KMS("Got NAK reply: req 0x%02x,
> reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg-
> >reply.u.nak.reason, txmsg->reply.u.nak.nak_data);
> +			DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s),
> reason 0x%02x (%s), nak data 0x%02x\n",
> +				      txmsg->reply.req_type,
> +				      drm_dp_mst_req_type_str(txmsg-
> >reply.req_type),
> +				      txmsg->reply.u.nak.reason,
> +				      drm_dp_mst_nak_reason_str(txmsg-
> >reply.u.nak.reason),
> +				      txmsg->reply.u.nak.nak_data);
>  		}
>  
>  		memset(&mgr->down_rep_recv, 0, sizeof(struct
> drm_dp_sideband_msg_rx));
> diff --git a/include/drm/drm_dp_helper.h
> b/include/drm/drm_dp_helper.h
> index 2a0fd9d7066e..2453767246fb 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -918,6 +918,7 @@
>  #define DP_PEER_DEVICE_DP_LEGACY_CONV	0x4
>  
>  /* DP 1.2 MST sideband request names DP 1.2a Table 2-80 */
> +#define DP_GET_MSG_TRANSACTION_VERSION	0x00 /* DP 1.3 */
>  #define DP_LINK_ADDRESS			0x01
>  #define DP_CONNECTION_STATUS_NOTIFY	0x02
>  #define DP_ENUM_PATH_RESOURCES		0x10