diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 46d88ef4f59a..9ca88e6c7882 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -433,6 +433,83 @@ static u8 drm_dp_downstream_port_count(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) return port_count; } +static int drm_dp_read_extended_dpcd_caps(struct drm_dp_aux *aux, + u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + u8 dpcd_ext[6]; + int ret; + + /* + * Prior to DP1.3 the bit represented by + * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved. + * If it is set DP_DPCD_REV at 0000h could be at a value less than + * the true capability of the panel. The only way to check is to + * then compare 0000h and 2200h. + */ + if (!(dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT)) + return 0; + + ret = drm_dp_dpcd_read(aux, DP_DP13_DPCD_REV, &dpcd_ext, + sizeof(dpcd_ext)); + if (ret < 0) + return ret; + if (ret != sizeof(dpcd_ext)) + return -EIO; + + if (dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) { + DRM_DEBUG_KMS("%s: Extended DPCD rev less than base DPCD rev (%d > %d)\n", + aux->name, dpcd[DP_DPCD_REV], + dpcd_ext[DP_DPCD_REV]); + return 0; + } + + if (!memcmp(dpcd, dpcd_ext, sizeof(dpcd_ext))) + return 0; + + DRM_DEBUG_KMS("%s: Base DPCD: %*ph\n", + aux->name, DP_RECEIVER_CAP_SIZE, dpcd); + + memcpy(dpcd, dpcd_ext, sizeof(dpcd_ext)); + + return 0; +} + +/** + * drm_dp_read_dpcd_caps() - read DPCD caps and extended DPCD caps if + * available + * @aux: DisplayPort AUX channel + * @dpcd: Buffer to store the resulting DPCD in + * + * Attempts to read the base DPCD caps for @aux. Additionally, this function + * checks for and reads the extended DPRX caps (%DP_DP13_DPCD_REV) if + * present. + * + * Returns: %0 if the DPCD was read successfully, negative error code + * otherwise. + */ +int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux, + u8 dpcd[DP_RECEIVER_CAP_SIZE]) +{ + int ret; + + ret = drm_dp_dpcd_read(aux, DP_DPCD_REV, dpcd, DP_RECEIVER_CAP_SIZE); + if (ret < 0) + return ret; + if (ret != DP_RECEIVER_CAP_SIZE || dpcd[DP_DPCD_REV] == 0) + return -EIO; + + ret = drm_dp_read_extended_dpcd_caps(aux, dpcd); + if (ret < 0) + return ret; + + DRM_DEBUG_KMS("%s: DPCD: %*ph\n", + aux->name, DP_RECEIVER_CAP_SIZE, dpcd); + + return ret; +} +EXPORT_SYMBOL(drm_dp_read_dpcd_caps); + /** * drm_dp_read_downstream_info() - read DPCD downstream port info if available * @aux: DisplayPort AUX channel diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 0de94fc6289b..284b15f84592 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -4449,62 +4449,6 @@ intel_dp_link_down(struct intel_encoder *encoder, } } -static void -intel_dp_extended_receiver_capabilities(struct intel_dp *intel_dp) -{ - struct drm_i915_private *i915 = dp_to_i915(intel_dp); - u8 dpcd_ext[6]; - - /* - * Prior to DP1.3 the bit represented by - * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved. - * if it is set DP_DPCD_REV at 0000h could be at a value less than - * the true capability of the panel. The only way to check is to - * then compare 0000h and 2200h. - */ - if (!(intel_dp->dpcd[DP_TRAINING_AUX_RD_INTERVAL] & - DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT)) - return; - - if (drm_dp_dpcd_read(&intel_dp->aux, DP_DP13_DPCD_REV, - &dpcd_ext, sizeof(dpcd_ext)) != sizeof(dpcd_ext)) { - drm_err(&i915->drm, - "DPCD failed read at extended capabilities\n"); - return; - } - - if (intel_dp->dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) { - drm_dbg_kms(&i915->drm, - "DPCD extended DPCD rev less than base DPCD rev\n"); - return; - } - - if (!memcmp(intel_dp->dpcd, dpcd_ext, sizeof(dpcd_ext))) - return; - - drm_dbg_kms(&i915->drm, "Base DPCD: %*ph\n", - (int)sizeof(intel_dp->dpcd), intel_dp->dpcd); - - memcpy(intel_dp->dpcd, dpcd_ext, sizeof(dpcd_ext)); -} - -bool -intel_dp_read_dpcd(struct intel_dp *intel_dp) -{ - struct drm_i915_private *i915 = dp_to_i915(intel_dp); - - if (drm_dp_dpcd_read(&intel_dp->aux, 0x000, intel_dp->dpcd, - sizeof(intel_dp->dpcd)) < 0) - return false; /* aux transfer failed */ - - intel_dp_extended_receiver_capabilities(intel_dp); - - drm_dbg_kms(&i915->drm, "DPCD: %*ph\n", (int)sizeof(intel_dp->dpcd), - intel_dp->dpcd); - - return intel_dp->dpcd[DP_DPCD_REV] != 0; -} - bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp) { u8 dprx = 0; @@ -4563,7 +4507,7 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp) /* this function is meant to be called only once */ drm_WARN_ON(&dev_priv->drm, intel_dp->dpcd[DP_DPCD_REV] != 0); - if (!intel_dp_read_dpcd(intel_dp)) + if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd) != 0) return false; drm_dp_read_desc(&intel_dp->aux, &intel_dp->desc, @@ -4650,7 +4594,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) { int ret; - if (!intel_dp_read_dpcd(intel_dp)) + if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd)) return false; /* diff --git a/drivers/gpu/drm/i915/display/intel_dp.h b/drivers/gpu/drm/i915/display/intel_dp.h index b901ab850cbd..0a3af3410d52 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.h +++ b/drivers/gpu/drm/i915/display/intel_dp.h @@ -99,7 +99,6 @@ bool intel_dp_source_supports_hbr3(struct intel_dp *intel_dp); bool intel_dp_get_link_status(struct intel_dp *intel_dp, u8 *link_status); -bool intel_dp_read_dpcd(struct intel_dp *intel_dp); bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp); int intel_dp_link_required(int pixel_clock, int bpp); int intel_dp_max_data_rate(int max_link_clock, int max_lanes); diff --git a/drivers/gpu/drm/i915/display/intel_lspcon.c b/drivers/gpu/drm/i915/display/intel_lspcon.c index b781bf469644..dc1b35559afd 100644 --- a/drivers/gpu/drm/i915/display/intel_lspcon.c +++ b/drivers/gpu/drm/i915/display/intel_lspcon.c @@ -571,7 +571,7 @@ bool lspcon_init(struct intel_digital_port *dig_port) return false; } - if (!intel_dp_read_dpcd(dp)) { + if (drm_dp_read_dpcd_caps(&dp->aux, dp->dpcd) != 0) { DRM_ERROR("LSPCON DPCD read failed\n"); return false; } diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index bc5cb8c503fb..85513eeb2196 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1607,6 +1607,9 @@ static inline ssize_t drm_dp_dpcd_writeb(struct drm_dp_aux *aux, return drm_dp_dpcd_write(aux, offset, &value, 1); } +int drm_dp_read_dpcd_caps(struct drm_dp_aux *aux, + u8 dpcd[DP_RECEIVER_CAP_SIZE]); + int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, u8 status[DP_LINK_STATUS_SIZE]);