[PATCH 2/2] drm/edid: fix Baseline_ELD_Len field in drm_edid_to_eld()

[Jani Nikula]

The Baseline_ELD_Len field does not include ELD Header Block size.

>From High Definition Audio Specification, Revision 1.0a:

	The header block is a fixed size of 4 bytes. The baseline block
	is variable size in multiple of 4 bytes, and its size is defined
	in the header block Baseline_ELD_Len field (in number of
	DWords).

Do not include the header size in Baseline_ELD_Len field. Fix all known
users of eld[2].

While at it, switch to DIV_ROUND_UP instead of open coding it.

Signed-off-by: Jani Nikula <jani.nikula at intel.com>

---

This is based on an audio rework series which is mid-way being merged to
i915. I don't think this should be cc: stable worthy, as, AFAICT, we
don't use the vendor block, and anyone reading SADs respecting SAD_Count
should stop at the same offset regardless of this patch. So I propose
this gets eventually merged via i915 without a rush.
---
 drivers/gpu/drm/drm_edid.c             |  7 +++++--
 drivers/gpu/drm/i915/intel_audio.c     | 16 ++++++++--------
 drivers/gpu/drm/nouveau/nv50_display.c |  3 ++-
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 3bf999134bcc..45aaa6f5ef36 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3128,9 +3128,12 @@ void drm_edid_to_eld(struct drm_connector *connector, struct edid *edid)
 		}
 	}
 	eld[5] |= sad_count << 4;
-	eld[2] = (20 + mnl + sad_count * 3 + 3) / 4;
 
-	DRM_DEBUG_KMS("ELD size %d, SAD count %d\n", (int)eld[2], sad_count);
+	eld[DRM_ELD_BASELINE_ELD_LEN] =
+		DIV_ROUND_UP(drm_eld_calc_baseline_block_size(eld), 4);
+
+	DRM_DEBUG_KMS("ELD size %d, SAD count %d\n",
+		      drm_eld_size(eld), sad_count);
 }
 EXPORT_SYMBOL(drm_edid_to_eld);
 
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index 20af973d7cba..439fa4afa18b 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -107,7 +107,7 @@ static bool intel_eld_uptodate(struct drm_connector *connector,
 	tmp &= ~bits_elda;
 	I915_WRITE(reg_elda, tmp);
 
-	for (i = 0; i < eld[2]; i++)
+	for (i = 0; i < drm_eld_size(eld) / 4; i++)
 		if (I915_READ(reg_edid) != *((uint32_t *)eld + i))
 			return false;
 
@@ -162,7 +162,7 @@ static void g4x_audio_codec_enable(struct drm_connector *connector,
 	len = (tmp >> 9) & 0x1f;		/* ELD buffer size */
 	I915_WRITE(G4X_AUD_CNTL_ST, tmp);
 
-	len = min_t(int, eld[2], len);
+	len = min(drm_eld_size(eld) / 4, len);
 	DRM_DEBUG_DRIVER("ELD size %d\n", len);
 	for (i = 0; i < len; i++)
 		I915_WRITE(G4X_HDMIW_HDMIEDID, *((uint32_t *)eld + i));
@@ -209,7 +209,7 @@ static void hsw_audio_codec_enable(struct drm_connector *connector,
 	int len, i;
 
 	DRM_DEBUG_KMS("Enable audio codec on pipe %c, %u bytes ELD\n",
-		      pipe_name(pipe), eld[2]);
+		      pipe_name(pipe), drm_eld_size(eld));
 
 	/* Enable audio presence detect, invalidate ELD */
 	tmp = I915_READ(HSW_AUD_PIN_ELD_CP_VLD);
@@ -225,8 +225,8 @@ static void hsw_audio_codec_enable(struct drm_connector *connector,
 	I915_WRITE(HSW_AUD_DIP_ELD_CTRL(pipe), tmp);
 
 	/* Up to 84 bytes of hw ELD buffer */
-	len = min_t(int, eld[2], 21);
-	for (i = 0; i < len; i++)
+	len = min(drm_eld_size(eld), 84);
+	for (i = 0; i < len / 4; i++)
 		I915_WRITE(HSW_AUD_EDID_DATA(pipe), *((uint32_t *)eld + i));
 
 	/* ELD valid */
@@ -315,7 +315,7 @@ static void ilk_audio_codec_enable(struct drm_connector *connector,
 	int aud_cntrl_st2;
 
 	DRM_DEBUG_KMS("Enable audio codec on port %c, pipe %c, %u bytes ELD\n",
-		      port_name(port), pipe_name(pipe), eld[2]);
+		      port_name(port), pipe_name(pipe), drm_eld_size(eld));
 
 	/* XXX: vblank wait here */
 
@@ -354,8 +354,8 @@ static void ilk_audio_codec_enable(struct drm_connector *connector,
 	I915_WRITE(aud_cntl_st, tmp);
 
 	/* Up to 84 bytes of hw ELD buffer */
-	len = min_t(int, eld[2], 21);
-	for (i = 0; i < len; i++)
+	len = min(drm_eld_size(eld), 84);
+	for (i = 0; i < len / 4; i++)
 		I915_WRITE(hdmiw_hdmiedid, *((uint32_t *)eld + i));
 
 	/* ELD valid */
diff --git a/drivers/gpu/drm/nouveau/nv50_display.c b/drivers/gpu/drm/nouveau/nv50_display.c
index ae873d1a8d46..d92c11484bd9 100644
--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -1680,7 +1680,8 @@ nv50_audio_mode_set(struct drm_encoder *encoder, struct drm_display_mode *mode)
 	drm_edid_to_eld(&nv_connector->base, nv_connector->edid);
 	memcpy(args.data, nv_connector->base.eld, sizeof(args.data));
 
-	nvif_mthd(disp->disp, 0, &args, sizeof(args.base) + args.data[2] * 4);
+	nvif_mthd(disp->disp, 0, &args,
+		  sizeof(args.base) + drm_eld_size(args.data);
 }
 
 static void
-- 
2.1.1