From 213f658d2c23fe2b1b257f04f8176085cd5680ee Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Thu, 27 Oct 2016 21:59:05 +0300 Subject: [PATCH] drm/i915: Assuming non-DP++ port if dvo_port is HDMI and there's no AUX ch specified in the VBT MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit My heuristic for detecting type 1 DVI DP++ adaptors based on the VBT port information apparently didn't susrvive the reality of buggy VBTs. In this particular case we have a machine with a natice HDMI port, but the VBT telsl us it's a DP++ port based on its capabilities. The dvo_port information in VBT does claim that we're dealing with a HDMI port though, but we have other machines which do the same even when they actually have DP++ ports. So that piece of information alone isn't sufficient to tell the two apart. After staring at a bunch of VBTs from various machines, I have to conclude that the only other semi-reliable clue we can use is the presence of the AUX channel in the VBT. On this particular machine AUX channel is specified as zero, whereas on some of the other machines which listed the DP++ port as HDMI have a non-zero AUX channel. I've also seen VBTs which have dvo_port a DP but have a zero AUX channel. I believe those we need to treat as DP ports, so we'll limit the AUX channel check to just the cases where dvo_port is HDMI. If we encounter any more serious failures with this heuristic I think we'll have to have to throw it out entirely. But that could mean that there is a risk of type 1 DVI dongle users getting greeted by a black screen, so I'd rather not go there unless absolutely necessary. Cc: Daniel Otero Cc: stable@vger.kernel.org Fixes: d61992565bd3 ("drm/i915: Determine DP++ type 1 DVI adaptor presence based on VBT") Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97994 Signed-off-by: Ville Syrjälä --- drivers/gpu/drm/i915/intel_bios.c | 32 ++++++++++++++++++++++++-------- drivers/gpu/drm/i915/intel_vbt_defs.h | 3 ++- 2 files changed, 26 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c index 5ab646ef8c9f..33ed05186810 100644 --- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -1147,7 +1147,7 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port, if (!child) return; - aux_channel = child->raw[25]; + aux_channel = child->common.aux_channel; ddc_pin = child->common.ddc_pin; is_dvi = child->common.device_type & DEVICE_TYPE_TMDS_DVI_SIGNALING; @@ -1677,7 +1677,8 @@ bool intel_bios_is_port_edp(struct drm_i915_private *dev_priv, enum port port) return false; } -bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv, enum port port) +static bool child_dev_is_dp_dual_mode(const union child_device_config *p_child, + enum port port) { static const struct { u16 dp, hdmi; @@ -1691,22 +1692,37 @@ bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv, enum por [PORT_D] = { DVO_PORT_DPD, DVO_PORT_HDMID, }, [PORT_E] = { DVO_PORT_DPE, DVO_PORT_HDMIE, }, }; - int i; if (port == PORT_A || port >= ARRAY_SIZE(port_mapping)) return false; - if (!dev_priv->vbt.child_dev_num) + if ((p_child->common.device_type & DEVICE_TYPE_DP_DUAL_MODE_BITS) != + (DEVICE_TYPE_DP_DUAL_MODE & DEVICE_TYPE_DP_DUAL_MODE_BITS)) + return false; + + if (p_child->common.dvo_port == port_mapping[port].dp) + return true; + + /* Only accept a HDMI dvo_port as DP++ if it has an AUX channel */ + if (p_child->common.dvo_port == port_mapping[port].hdmi && + p_child->common.aux_channel != 0) + return true; + + return false; +} + +bool intel_bios_is_port_dp_dual_mode(struct drm_i915_private *dev_priv, enum port port) +{ + int i; + + if (port == PORT_A) return false; for (i = 0; i < dev_priv->vbt.child_dev_num; i++) { const union child_device_config *p_child = &dev_priv->vbt.child_dev[i]; - if ((p_child->common.dvo_port == port_mapping[port].dp || - p_child->common.dvo_port == port_mapping[port].hdmi) && - (p_child->common.device_type & DEVICE_TYPE_DP_DUAL_MODE_BITS) == - (DEVICE_TYPE_DP_DUAL_MODE & DEVICE_TYPE_DP_DUAL_MODE_BITS)) + if (child_dev_is_dp_dual_mode(p_child, port)) return true; } diff --git a/drivers/gpu/drm/i915/intel_vbt_defs.h b/drivers/gpu/drm/i915/intel_vbt_defs.h index 68db9621f1f0..8886cab19f98 100644 --- a/drivers/gpu/drm/i915/intel_vbt_defs.h +++ b/drivers/gpu/drm/i915/intel_vbt_defs.h @@ -280,7 +280,8 @@ struct common_child_dev_config { u8 dp_support:1; u8 tmds_support:1; u8 support_reserved:5; - u8 not_common3[12]; + u8 aux_channel; + u8 not_common3[11]; u8 iboost_level; } __packed; -- 2.7.4