Re: [PATCH] drm/i915: Add debugfs entry for DRRS

[Daniel Vetter <daniel@ffwll.ch>]

On Thu, Jan 22, 2015 at 10:15:21PM +0530, Ramalingam C wrote:
> From: Vandana Kannan <vandana.kannan@intel.com>
> 
> Adding a debugfs entry to determine if DRRS is supported or not
> 
> V2: [By Ram]: Following details about the active crtc will be filled
> 	in seq-file of the debugfs
> 	1. Encoder output type
> 	2. DRRS Support on this CRTC
> 	3. DRRS current state
> 	4. Current Vrefresh
> Format is as follows:
> 
> CRTC 1:  Output: eDP, DRRS Supported: Yes (Seamless), DRRS_State: DRRS_HIGH_RR, Vrefresh: 60
> CRTC 2:  Output: HDMI, DRRS Supported : No, VBT DRRS_type: Seamless
> CRTC 1:  Output: eDP, DRRS Supported: Yes (Seamless), DRRS_State: DRRS_LOW_RR, Vrefresh: 40
> CRTC 2:  Output: HDMI, DRRS Supported : No, VBT DRRS_type: Seamless
> 
> Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c |   93 +++++++++++++++++++++++++++++++++++
>  1 file changed, 93 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 2ad4c48..47f1f65 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2819,6 +2819,98 @@ static int i915_ddb_info(struct seq_file *m, void *unused)
>  	return 0;
>  }
>  
> +static int i915_drrs_status(struct seq_file *m, void *unused)
> +{
> +	struct drm_info_node *node = m->private;
> +	struct drm_device *dev = node->minor->dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	struct i915_drrs *drrs = &dev_priv->drrs;
> +	struct intel_crtc *intel_crtc;
> +	struct intel_encoder *intel_encoder;
> +	int active_crtc_cnt = 0, vrefresh = 0;
> +
> +	for_each_intel_crtc(dev, intel_crtc) {
> +		if (intel_crtc->active) {
> +			active_crtc_cnt++;
> +			seq_puts(m, "CRTC");
> +			seq_put_decimal_ull(m, ' ', active_crtc_cnt);
> +			seq_puts(m, ":  ");
> +			for_each_encoder_on_crtc(dev, &intel_crtc->base,
> +								intel_encoder) {
> +				/* Encoder connected on this CRTC */
> +				switch (intel_encoder->type) {
> +				case INTEL_OUTPUT_EDP:
> +					seq_puts(m, "Output: eDP, ");
> +					break;
> +				case INTEL_OUTPUT_DSI:
> +					seq_puts(m, "Output: DSI, ");
> +					break;
> +				case INTEL_OUTPUT_HDMI:
> +					seq_puts(m, "Output: HDMI, ");
> +					break;
> +				case INTEL_OUTPUT_DISPLAYPORT:
> +					seq_puts(m, "Output: DP, ");
> +					break;
> +				default:
> +					seq_puts(m, "Output: Others (id");
> +					seq_put_decimal_ull(m, '=',
> +							intel_encoder->type);
> +					seq_puts(m, "), ");
> +				}
> +			}
> +
> +			if (intel_crtc->config->has_drrs) {
> +				struct intel_panel *panel;
> +
> +				panel = &drrs->dp->attached_connector->panel;
> +				/* DRRS Supported */
> +				seq_puts(m,
> +					"DRRS Supported: Yes (Seamless), ");
> +				if (drrs->refresh_rate_type == DRRS_HIGH_RR) {
> +					seq_puts(m,
> +						"DRRS_State: DRRS_HIGH_RR, ");
> +					vrefresh = panel->fixed_mode->vrefresh;
> +				} else if (drrs->refresh_rate_type ==
> +								DRRS_LOW_RR) {
> +					seq_puts(m,
> +						"DRRS_State: DRRS_LOW_RR, ");
> +					vrefresh =
> +						panel->downclock_mode->vrefresh;
> +				} else {
> +					seq_puts(m, "DRRS_State: Unknown");
> +					seq_put_decimal_ull(m, '(',
> +						drrs->refresh_rate_type);
> +					seq_puts(m, "), ");
> +				}
> +				seq_puts(m, "Vrefresh:");
> +				seq_put_decimal_ull(m, ' ', vrefresh);
> +
> +			} else {
> +				/* DRRS not supported. Print the VBT parameter*/
> +				seq_puts(m, "DRRS Supported : No, ");
> +				if (dev_priv->vbt.drrs_type ==
> +							STATIC_DRRS_SUPPORT) {
> +					seq_puts(m,
> +						"VBT DRRS_type: Static");
> +				} else if (dev_priv->vbt.drrs_type ==
> +							SEAMLESS_DRRS_SUPPORT) {
> +					seq_puts(m,
> +						"VBT DRRS_type: Seamless");
> +				} else if (dev_priv->vbt.drrs_type ==
> +							DRRS_NOT_SUPPORTED) {
> +					seq_puts(m, "VBT DRRS_type: None");
> +				}
> +			}

This is an example of were strictly following checkpatch warnings and
pedantically breaking lines results in rather hard to read code:
The function is really long, and has about 6 indent levels. Imo it would
greatly benefit from extracting some helper functions to do the
inner-level printing. There's piles of examples in i915_debugfs where we
loop over a bunch of objects and punt all the real output to a small
helper function.
-Daniel

> +			seq_puts(m, "\n");
> +		}
> +	}
> +
> +	if (!active_crtc_cnt)
> +		seq_puts(m, "No active crtc found\n");
> +
> +	return 0;
> +}
> +
>  struct pipe_crc_info {
>  	const char *name;
>  	struct drm_device *dev;
> @@ -4433,6 +4525,7 @@ static const struct drm_info_list i915_debugfs_list[] = {
>  	{"i915_dp_mst_info", i915_dp_mst_info, 0},
>  	{"i915_wa_registers", i915_wa_registers, 0},
>  	{"i915_ddb_info", i915_ddb_info, 0},
> +	{"i915_drrs_status", i915_drrs_status, 0},
>  };
>  #define I915_DEBUGFS_ENTRIES ARRAY_SIZE(i915_debugfs_list)
>  
> -- 
> 1.7.9.5
> 
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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