[PATCH 01/12] drm/i915/display: Modify debugfs for joiner to force n pipes

[Kandpal, Suraj]

> -----Original Message-----
> From: Intel-gfx <intel-gfx-bounces at lists.freedesktop.org> On Behalf Of Ankit
> Nautiyal
> Sent: Thursday, July 18, 2024 1:48 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: Lisovskiy, Stanislav <stanislav.lisovskiy at intel.com>; Saarinen, Jani
> <jani.saarinen at intel.com>; ville.syrjala at linux.intel.com
> Subject: [PATCH 01/12] drm/i915/display: Modify debugfs for joiner to force n
> pipes
> 
> At the moment, the debugfs for joiner allows only to force enable/disable pipe
> joiner for 2 pipes. Modify it to force join 'n' number of pipes.
> This will help in case of ultra joiner where 4 pipes are joined.
> 

I think saying join n number of pipes gives the right idea of what the functionality and Patch is doing.
We can only join 2 or 4 pipes I think the commit message should make that clear

> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> ---
>  .../drm/i915/display/intel_display_debugfs.c  | 71 ++++++++++++++++++-
>  .../drm/i915/display/intel_display_types.h    |  8 ++-
>  drivers/gpu/drm/i915/display/intel_dp.c       |  2 +-
>  3 files changed, 77 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> index 5cf9b4af9adf..18f3d83265ce 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> @@ -1497,6 +1497,73 @@ static int intel_crtc_pipe_show(struct seq_file *m,
> void *unused)  }  DEFINE_SHOW_ATTRIBUTE(intel_crtc_pipe);
> 
> +static int i915_joiner_show(struct seq_file *m, void *data) {
> +	struct intel_connector *connector = m->private;
> +	struct drm_i915_private *i915 = to_i915(connector->base.dev);
> +	int ret;
> +
> +	ret = drm_modeset_lock_single_interruptible(&i915-
> >drm.mode_config.connection_mutex);
> +	if (ret)
> +		return ret;
> +
> +	seq_printf(m, "Force_joined_pipes: %d\n",
> +connector->force_joined_pipes);
> +
> +	drm_modeset_unlock(&i915->drm.mode_config.connection_mutex);
> +
> +	return ret;
> +}
> +
> +static ssize_t i915_joiner_write(struct file *file,
> +				 const char __user *ubuf,
> +				 size_t len, loff_t *offp)
> +{
> +	struct seq_file *m = file->private_data;
> +	struct intel_connector *connector = m->private;
> +	struct drm_i915_private *i915 = to_i915(connector->base.dev);
> +	int force_join_pipes = 0;
> +	int ret;
> +
> +	if (len == 0)
> +		return 0;
> +
> +	drm_dbg(&i915->drm,
> +		"Copied %zu bytes from user to force joiner\n", len);
> +
> +	ret = kstrtoint_from_user(ubuf, len, 0, &force_join_pipes);
> +	if (ret < 0)
> +		return ret;
> +
> +	drm_dbg(&i915->drm, "Got %d for force joining pipes\n",
> +force_join_pipes);
> +
> +	if (force_join_pipes < INTEL_PIPE_JOINER_NONE ||
> +	    force_join_pipes >= INTEL_PIPE_JOINER_INVALID) {
> +		drm_dbg(&i915->drm, "Ignoring Invalid num of pipes %d for
> force joining\n",
> +			force_join_pipes);
> +		connector->force_joined_pipes = INTEL_PIPE_JOINER_NONE;
> +	} else {
> +		connector->force_joined_pipes = force_join_pipes;
> +	}
> +
> +	*offp += len;
> +
> +	return len;
> +}
> +
> +static int i915_joiner_open(struct inode *inode, struct file *file) {
> +	return single_open(file, i915_joiner_show, inode->i_private); }
> +
> +static const struct file_operations i915_joiner_fops = {
> +	.owner = THIS_MODULE,
> +	.open = i915_joiner_open,
> +	.read = seq_read,
> +	.llseek = seq_lseek,
> +	.release = single_release,
> +	.write = i915_joiner_write
> +};
> +
>  /**
>   * intel_connector_debugfs_add - add i915 specific connector debugfs files
>   * @connector: pointer to a registered intel_connector @@ -1546,8 +1613,8
> @@ void intel_connector_debugfs_add(struct intel_connector *connector)
>  	if (DISPLAY_VER(i915) >= 11 &&
>  	    (connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
>  	     connector_type == DRM_MODE_CONNECTOR_eDP)) {
> -		debugfs_create_bool("i915_bigjoiner_force_enable", 0644,
> root,
> -				    &connector->force_bigjoiner_enable);
> +		debugfs_create_file("i915_joiner_force_enable", 0644, root,
> +				    connector, &i915_joiner_fops);
>  	}
> 
>  	if (connector_type == DRM_MODE_CONNECTOR_DSI || diff --git
> a/drivers/gpu/drm/i915/display/intel_display_types.h
> b/drivers/gpu/drm/i915/display/intel_display_types.h
> index a9d2acdc51a4..14c78b18ffa1 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -613,6 +613,12 @@ struct intel_hdcp {
>  	enum transcoder stream_transcoder;
>  };
> 
> +enum intel_joiner_pipe_count {
> +	INTEL_PIPE_JOINER_NONE = 0,
> +	INTEL_PIPE_JOINER_BIG = 2,
> +	INTEL_PIPE_JOINER_INVALID,
> +};

Also the naming here should be intel_pipe_joiner_count since the difference in enum variable and enum defines Does not seem right.
Also I think the ULTRA enum should be defined sooner rather than later it will help reduce a lot of magic numbers being used in ultrajoiner
and big joiner checks later on.
> +
>  struct intel_connector {
>  	struct drm_connector base;
>  	/*
> @@ -651,7 +657,7 @@ struct intel_connector {
> 
>  	struct intel_dp *mst_port;
> 
> -	bool force_bigjoiner_enable;
> +	enum intel_joiner_pipe_count force_joined_pipes;
> 

Naming here should be force_pipes_joined.
I think this whole patch series has a trend of naming it as joined pipe I think that should be changed to pipe joined

Regards,
Suraj Kandpal
>  	struct {
>  		struct drm_dp_aux *dsc_decompression_aux; diff --git
> a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index d4b1b18453dc..30442c9da06b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -1164,7 +1164,7 @@ bool intel_dp_need_joiner(struct intel_dp *intel_dp,
>  		return false;
> 
>  	return clock > i915->display.cdclk.max_dotclk_freq || hdisplay > 5120
> ||
> -	       connector->force_bigjoiner_enable;
> +	       connector->force_joined_pipes == INTEL_PIPE_JOINER_BIG;
>  }
> 
>  bool intel_dp_has_dsc(const struct intel_connector *connector)
> --
> 2.45.2