From 9ff7a1b0ba823b6cdefc10fc641b8289274d7d81 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Wed, 26 Oct 2016 19:29:19 +0300 Subject: [PATCH] drm: Print some debug/error info during DP dual mode detect MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit There's at least one LSPCON device that occasionally returns an unexpected adaptor ID which leads to a failed detect. Print some debug info to help debugging this and future cases. Also print an error for an unexpected adaptor ID, so users can report it. v2: - s/adapter/adaptor/ and add code comment about incorrect type 1 adaptor IDs. (Ville) Cc: dri-devel@lists.freedesktop.org Cc: Ville Syrjälä Signed-off-by: Imre Deak Reviewed-by: Ville Syrjälä Signed-off-by: Sean Paul Link: http://patchwork.freedesktop.org/patch/msgid/1477499359-12001-1-git-send-email-imre.deak@intel.com --- drivers/gpu/drm/drm_dp_dual_mode_helper.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/gpu/drm/drm_dp_dual_mode_helper.c b/drivers/gpu/drm/drm_dp_dual_mode_helper.c index 488355bdafb9..e02563966271 100644 --- a/drivers/gpu/drm/drm_dp_dual_mode_helper.c +++ b/drivers/gpu/drm/drm_dp_dual_mode_helper.c @@ -142,6 +142,11 @@ static bool is_hdmi_adaptor(const char hdmi_id[DP_DUAL_MODE_HDMI_ID_LEN]) sizeof(dp_dual_mode_hdmi_id)) == 0; } +static bool is_type1_adaptor(uint8_t adaptor_id) +{ + return adaptor_id == 0 || adaptor_id == 0xff; +} + static bool is_type2_adaptor(uint8_t adaptor_id) { return adaptor_id == (DP_DUAL_MODE_TYPE_TYPE2 | @@ -193,6 +198,8 @@ enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter) */ ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_HDMI_ID, hdmi_id, sizeof(hdmi_id)); + DRM_DEBUG_KMS("DP dual mode HDMI ID: %*pE (err %zd)\n", + ret ? 0 : (int)sizeof(hdmi_id), hdmi_id, ret); if (ret) return DRM_DP_DUAL_MODE_UNKNOWN; @@ -210,6 +217,8 @@ enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter) */ ret = drm_dp_dual_mode_read(adapter, DP_DUAL_MODE_ADAPTOR_ID, &adaptor_id, sizeof(adaptor_id)); + DRM_DEBUG_KMS("DP dual mode adaptor ID: %02x (err %zd)\n", + adaptor_id, ret); if (ret == 0) { if (is_lspcon_adaptor(hdmi_id, adaptor_id)) return DRM_DP_DUAL_MODE_LSPCON; @@ -219,6 +228,15 @@ enum drm_dp_dual_mode_type drm_dp_dual_mode_detect(struct i2c_adapter *adapter) else return DRM_DP_DUAL_MODE_TYPE2_DVI; } + /* + * If neither a proper type 1 ID nor a broken type 1 adaptor + * as described above, assume type 1, but let the user know + * that we may have misdetected the type. + */ + if (!is_type1_adaptor(adaptor_id) && adaptor_id != hdmi_id[0]) + DRM_ERROR("Unexpected DP dual mode adaptor ID %02x\n", + adaptor_id); + } if (is_hdmi_adaptor(hdmi_id)) -- 2.20.1