From 70a6587dca37a3cf12ab323f7fd73266abfc274f Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Mon, 9 Sep 2024 17:46:50 +0300 Subject: drm/dp_mst: Fix DSC decompression detection in Synaptics branch devices Atm it's assumed that all Synaptics MST branch devices support DSC, which is not exposed via a DP-to-DP peer device, rather a control flag in the branch device's UFP DPCD applying to all the streams going through it. This isn't true for all adapters with this branch device though (for instance the Cakitte USBC->2xHDMI adapter reported in the Closes link below doesn't support DSC). Fix the above by advertising the DSC decompression support only if the capability flag for this in the UFP DPCD is actually set. Cc: Lyude Paul Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12047 Signed-off-by: Imre Deak Reviewed-by: Lyude Paul Link: https://patchwork.freedesktop.org/patch/msgid/20240909144650.2931258-1-imre.deak@intel.com --- drivers/gpu/drm/display/drm_dp_mst_topology.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/display') diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index fc2ceae61db2..ac5f1f34e51a 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -6057,6 +6057,7 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) struct drm_dp_aux *immediate_upstream_aux; struct drm_dp_mst_port *fec_port; struct drm_dp_desc desc = {}; + u8 upstream_dsc; u8 endpoint_fec; u8 endpoint_dsc; @@ -6083,8 +6084,6 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) /* DP-to-DP peer device */ if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) { - u8 upstream_dsc; - if (drm_dp_dpcd_read(&port->aux, DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) return NULL; @@ -6130,6 +6129,13 @@ struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD)) { u8 dpcd_ext[DP_RECEIVER_CAP_SIZE]; + if (drm_dp_dpcd_read(immediate_upstream_aux, + DP_DSC_SUPPORT, &upstream_dsc, 1) != 1) + return NULL; + + if (!(upstream_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED)) + return NULL; + if (drm_dp_read_dpcd_caps(immediate_upstream_aux, dpcd_ext) < 0) return NULL; -- cgit v1.2.3 From f0fa69b5011a45394554fb8061d74fee4d7cd72c Mon Sep 17 00:00:00 2001 From: Derek Foreman Date: Tue, 27 Aug 2024 11:39:04 -0500 Subject: drm/connector: hdmi: Fix writing Dynamic Range Mastering infoframes The largest infoframe we create is the DRM (Dynamic Range Mastering) infoframe which is 26 bytes + a 4 byte header, for a total of 30 bytes. With HDMI_MAX_INFOFRAME_SIZE set to 29 bytes, as it is now, we allocate too little space to pack a DRM infoframe in write_device_infoframe(), leading to an ENOSPC return from hdmi_infoframe_pack(), and never calling the connector's write_infoframe() vfunc. Instead of having HDMI_MAX_INFOFRAME_SIZE defined in two places, replace HDMI_MAX_INFOFRAME_SIZE with HDMI_INFOFRAME_SIZE(MAX) and make MAX 27 bytes - which is defined by the HDMI specification to be the largest infoframe payload. Fixes: f378b77227bc ("drm/connector: hdmi: Add Infoframes generation") Fixes: c602e4959a0c ("drm/connector: hdmi: Create Infoframe DebugFS entries") Signed-off-by: Derek Foreman Acked-by: Maxime Ripard Reviewed-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20240827163918.48160-1-derek.foreman@collabora.com Signed-off-by: Maxime Ripard --- drivers/gpu/drm/display/drm_hdmi_state_helper.c | 4 +--- drivers/gpu/drm/drm_debugfs.c | 4 +--- include/linux/hdmi.h | 9 +++++++++ 3 files changed, 11 insertions(+), 6 deletions(-) (limited to 'drivers/gpu/drm/display') diff --git a/drivers/gpu/drm/display/drm_hdmi_state_helper.c b/drivers/gpu/drm/display/drm_hdmi_state_helper.c index 7854820089ec..feb7a3a75981 100644 --- a/drivers/gpu/drm/display/drm_hdmi_state_helper.c +++ b/drivers/gpu/drm/display/drm_hdmi_state_helper.c @@ -521,8 +521,6 @@ int drm_atomic_helper_connector_hdmi_check(struct drm_connector *connector, } EXPORT_SYMBOL(drm_atomic_helper_connector_hdmi_check); -#define HDMI_MAX_INFOFRAME_SIZE 29 - static int clear_device_infoframe(struct drm_connector *connector, enum hdmi_infoframe_type type) { @@ -563,7 +561,7 @@ static int write_device_infoframe(struct drm_connector *connector, { const struct drm_connector_hdmi_funcs *funcs = connector->hdmi.funcs; struct drm_device *dev = connector->dev; - u8 buffer[HDMI_MAX_INFOFRAME_SIZE]; + u8 buffer[HDMI_INFOFRAME_SIZE(MAX)]; int ret; int len; diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c index 6b239a24f1df..9d3e6dd68810 100644 --- a/drivers/gpu/drm/drm_debugfs.c +++ b/drivers/gpu/drm/drm_debugfs.c @@ -520,8 +520,6 @@ static const struct file_operations drm_connector_fops = { .write = connector_write }; -#define HDMI_MAX_INFOFRAME_SIZE 29 - static ssize_t audio_infoframe_read(struct file *filp, char __user *ubuf, size_t count, loff_t *ppos) { @@ -579,7 +577,7 @@ static ssize_t _f##_read_infoframe(struct file *filp, \ struct drm_connector *connector; \ union hdmi_infoframe *frame; \ struct drm_device *dev; \ - u8 buf[HDMI_MAX_INFOFRAME_SIZE]; \ + u8 buf[HDMI_INFOFRAME_SIZE(MAX)]; \ ssize_t len = 0; \ \ connector = filp->private_data; \ diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h index 3bb87bf6bc65..455f855bc084 100644 --- a/include/linux/hdmi.h +++ b/include/linux/hdmi.h @@ -59,6 +59,15 @@ enum hdmi_infoframe_type { #define HDMI_DRM_INFOFRAME_SIZE 26 #define HDMI_VENDOR_INFOFRAME_SIZE 4 +/* + * HDMI 1.3a table 5-14 states that the largest InfoFrame_length is 27, + * not including the packet header or checksum byte. We include the + * checksum byte in HDMI_INFOFRAME_HEADER_SIZE, so this should allow + * HDMI_INFOFRAME_SIZE(MAX) to be the largest buffer we could ever need + * for any HDMI infoframe. + */ +#define HDMI_MAX_INFOFRAME_SIZE 27 + #define HDMI_INFOFRAME_SIZE(type) \ (HDMI_INFOFRAME_HEADER_SIZE + HDMI_ ## type ## _INFOFRAME_SIZE) -- cgit v1.2.3