Re: [PATCH] drm/i915/display: Extend i915_display_info with Type-C port details

[Imre Deak <imre.deak@intel.com>]

On Thu, Sep 25, 2025 at 04:51:53PM -0700, Khaled Almahallawy wrote:
> Expose key Type-C port data in i915_display_info to make it easier to
> understand the port configuration and active mode, especially whether
> the link is in DP-Alt or TBT-Alt, without having to scan kernel logs.
> 
> Tested in DP-Alt, TBT-Alt, SST, and MST.
> 
> Expected output:
> 
> [CONNECTOR:290:DP-2]: status: connected
> 	TC Port: E/TC#2 mode: tbt-alt pin assignment: - max lanes: 4
> 	physical dimensions: 600x340mm
> ...
> [CONNECTOR:263:DP-5]: status: connected
> 	TC Port: G/TC#4 mode: dp-alt pin assignment: C max lanes: 4
> 	physical dimensions: 610x350mm
> 
> Cc: Imre Deak <imre.deak@intel.com>
> Cc: Jani Nikula <jani.nikula@intel.com>
> Signed-off-by: Khaled Almahallawy <khaled.almahallawy@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display_debugfs.c |  4 ++++
>  drivers/gpu/drm/i915/display/intel_tc.c              | 10 ++++++++++
>  drivers/gpu/drm/i915/display/intel_tc.h              |  3 +++
>  3 files changed, 17 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> index 10dddec3796f..6687fc18e1f5 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> @@ -47,6 +47,7 @@
>  #include "intel_psr_regs.h"
>  #include "intel_vdsc.h"
>  #include "intel_wm.h"
> +#include "intel_tc.h"
>  
>  static struct intel_display *node_to_intel_display(struct drm_info_node *node)
>  {
> @@ -254,6 +255,9 @@ static void intel_connector_info(struct seq_file *m,
>  	if (connector->status == connector_status_disconnected)
>  		return;
>  
> +	if (intel_encoder_is_tc(intel_attached_encoder(intel_connector)))
> +		intel_tc_info(m, intel_attached_dig_port(intel_connector));
> +
>  	seq_printf(m, "\tphysical dimensions: %dx%dmm\n",
>  		   connector->display_info.width_mm,
>  		   connector->display_info.height_mm);
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
> index c4a5601c5107..4cd7ccac28b7 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.c
> +++ b/drivers/gpu/drm/i915/display/intel_tc.c
> @@ -1703,6 +1703,16 @@ void intel_tc_port_sanitize_mode(struct intel_digital_port *dig_port,
>  	mutex_unlock(&tc->lock);
>  }
>  
> +void intel_tc_info(struct seq_file *m,  struct intel_digital_port *dig_port)
> +{
> +	struct intel_tc_port *tc = to_tc_port(dig_port);
> +
> +	seq_printf(m, "\tTC Port: %s mode: %s pin assignment: %c max lanes: %d\n", tc->port_name,
> +		   tc_port_mode_name(tc->mode),
> +		   pin_assignment_name(tc->pin_assignment),
> +		   tc->max_lane_count);

This also requires tc->lock, could you lock/unlock it around the printf?

> +}
> +
>  /*
>   * The type-C ports are different because even when they are connected, they may
>   * not be available/usable by the graphics driver: see the comment on
> diff --git a/drivers/gpu/drm/i915/display/intel_tc.h b/drivers/gpu/drm/i915/display/intel_tc.h
> index fff8b96e4972..3e983d1cc0b8 100644
> --- a/drivers/gpu/drm/i915/display/intel_tc.h
> +++ b/drivers/gpu/drm/i915/display/intel_tc.h
> @@ -7,6 +7,7 @@
>  #define __INTEL_TC_H__
>  
>  #include <linux/types.h>
> +#include <linux/seq_file.h>
>  
>  struct intel_crtc_state;
>  struct intel_digital_port;
> @@ -113,4 +114,6 @@ void intel_tc_port_cleanup(struct intel_digital_port *dig_port);
>  
>  bool intel_tc_cold_requires_aux_pw(struct intel_digital_port *dig_port);
>  
> +void intel_tc_info(struct seq_file *m,  struct intel_digital_port *dig_port);
> +
>  #endif /* __INTEL_TC_H__ */
> -- 
> 2.43.0
>