linux-kernel - [PATCH 2/5] drm: Use new mode_valid() helpers in connector probe helper

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Message-Id: <bad497adb69277aa65d6727acd74328a30d986ef.1493906290.git.joabreu@synopsys.com>
Date:   Thu,  4 May 2017 15:11:39 +0100
From:   Jose Abreu <Jose.Abreu@...opsys.com>
To:     dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Cc:     Jose Abreu <Jose.Abreu@...opsys.com>,
        Carlos Palminha <CARLOS.PALMINHA@...opsys.com>,
        Alexey Brodkin <Alexey.Brodkin@...opsys.com>,
        Ville Syrjälä 
        <ville.syrjala@...ux.intel.com>,
        Daniel Vetter <daniel.vetter@...ll.ch>,
        Dave Airlie <airlied@...ux.ie>,
        Andrzej Hajda <a.hajda@...sung.com>,
        Archit Taneja <architt@...eaurora.org>
Subject: [PATCH 2/5] drm: Use new mode_valid() helpers in connector probe helper

This changes the connector probe helper function to use the new
encoder->mode_valid() and crtc->mode_valid() helper callbacks to
validate the modes.

The new callbacks are optional so the behaviour remains the same
if they are not implemented. If they are, then the code loops
through all the connector's encodersXcrtcs and calls the
callback.

If at least a valid encoderXcrtc combination is found which
accepts the mode then the function returns MODE_OK.

Signed-off-by: Jose Abreu <joabreu@...opsys.com>
Cc: Carlos Palminha <palminha@...opsys.com>
Cc: Alexey Brodkin <abrodkin@...opsys.com>
Cc: Ville Syrjälä <ville.syrjala@...ux.intel.com>
Cc: Daniel Vetter <daniel.vetter@...ll.ch>
Cc: Dave Airlie <airlied@...ux.ie>
Cc: Andrzej Hajda <a.hajda@...sung.com>
Cc: Archit Taneja <architt@...eaurora.org>
---
 drivers/gpu/drm/drm_probe_helper.c | 71 +++++++++++++++++++++++++++++++++++---
 1 file changed, 67 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
index 1b0c14a..bf19f82 100644
--- a/drivers/gpu/drm/drm_probe_helper.c
+++ b/drivers/gpu/drm/drm_probe_helper.c
@@ -80,6 +80,67 @@
 	return MODE_OK;
 }
 
+static enum drm_mode_status
+drm_mode_validate_connector(struct drm_connector *connector,
+			    struct drm_display_mode *mode)
+{
+	const struct drm_connector_helper_funcs *connector_funcs =
+		connector->helper_private;
+	struct drm_device *dev = connector->dev;
+	uint32_t *ids = connector->encoder_ids;
+	enum drm_mode_status ret = MODE_OK;
+	unsigned int i;
+
+	/* Step 1: Validate against connector */
+	if (connector_funcs && connector_funcs->mode_valid)
+		ret = connector_funcs->mode_valid(connector, mode);
+
+	if (ret != MODE_OK)
+		return ret;
+
+	/* Step 2: Validate against encoders and crtcs */
+	for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) {
+		struct drm_encoder *encoder = drm_encoder_find(dev, ids[i]);
+		const struct drm_encoder_helper_funcs *encoder_funcs;
+		struct drm_crtc *crtc;
+
+		if (!encoder)
+			continue;
+
+		encoder_funcs = encoder->helper_private;
+		if (encoder_funcs && encoder_funcs->mode_valid)
+			ret = encoder_funcs->mode_valid(encoder, mode);
+		else
+			ret = MODE_OK; /* encoder accepts everything */
+
+		/* No point in continuing for crtc check as this encoder will
+		 * not accept the mode anyway. If all encoders reject the mode
+		 * then, at exit, ret will not be MODE_OK. */
+		if (ret != MODE_OK)
+			continue;
+
+		drm_for_each_crtc(crtc, dev) {
+			const struct drm_crtc_helper_funcs *crtc_funcs;
+
+			if (!drm_encoder_crtc_ok(encoder, crtc))
+				continue;
+
+			crtc_funcs = crtc->helper_private;
+			if (!crtc_funcs || !crtc_funcs->mode_valid)
+				return MODE_OK; /* crtc accepts everything */
+
+			ret = crtc_funcs->mode_valid(crtc, mode);
+			if (ret == MODE_OK)
+				/* If we get to this point there is at least
+				 * one combination of encoder+crtc that works
+				 * for this mode. Lets return now. */
+				return ret;
+		}
+	}
+
+	return ret;
+}
+
 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
 {
 	struct drm_cmdline_mode *cmdline_mode;
@@ -283,8 +344,10 @@ void drm_kms_helper_poll_enable(struct drm_device *dev)
  *      (if specified)
  *    - drm_mode_validate_flag() checks the modes against basic connector
  *      capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
- *    - the optional &drm_connector_helper_funcs.mode_valid helper can perform
- *      driver and/or hardware specific checks
+ *    - the optional &drm_connector_helper_funcs.mode_valid,
+ *    	&drm_crtc_helper_funcs.mode_valid and
+ *    	&drm_encoder_helper_funcs.mode_valid helpers can perform driver and/or
+ *    	hardware specific checks
  *
  * 5. Any mode whose status is not OK is pruned from the connector's modes list,
  *    accompanied by a debug message indicating the reason for the mode's
@@ -428,8 +491,8 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
 		if (mode->status == MODE_OK)
 			mode->status = drm_mode_validate_flag(mode, mode_flags);
 
-		if (mode->status == MODE_OK && connector_funcs->mode_valid)
-			mode->status = connector_funcs->mode_valid(connector,
+		if (mode->status == MODE_OK)
+			mode->status = drm_mode_validate_connector(connector,
 								   mode);
 	}
 
-- 
1.9.1