From 5a6a7c93318326d150069b587cfa5def69372d41 Mon Sep 17 00:00:00 2001
From: Jani Nikula <jani.nikula@intel.com>
Date: Mon, 11 Apr 2022 17:00:31 +0300
Subject: drm/edid: use EDID block read helper in drm_do_get_edid()
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Git-commit: c12561ce43358ce59fc0f2275fc1853e24980908
Patch-mainline: v5.19-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Convert drm_do_get_edit() from the base block read helper to the generic
block read helper. There's quite a bit going on here, as the corrupt and
null EDID information is moved back to the caller. As we see, they were
not all that clear to begin with, and this change underlines that.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/3bcf98453770757ee93386da0cfbc6552d42a312.1649685475.git.jani.nikula@intel.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/drm_edid.c | 62 ++++++++++++++------------------------
 1 file changed, 23 insertions(+), 39 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 11276d226b37..d3951ac44f8f 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -2076,44 +2076,6 @@ static enum edid_block_status edid_block_read(void *block, unsigned int block_nu
 	return status;
 }
 
-static struct edid *drm_do_get_edid_base_block(struct drm_connector *connector,
-					       read_block_fn read_block,
-					       void *context)
-{
-	int *null_edid_counter = connector ? &connector->null_edid_counter : NULL;
-	bool *edid_corrupt = connector ? &connector->edid_corrupt : NULL;
-	void *edid;
-	int try;
-
-	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
-	if (edid == NULL)
-		return NULL;
-
-	/* base block fetch */
-	for (try = 0; try < 4; try++) {
-		if (read_block(context, edid, 0, EDID_LENGTH))
-			goto out;
-		if (drm_edid_block_valid(edid, 0, false, edid_corrupt))
-			break;
-		if (try == 0 && edid_block_is_zero(edid)) {
-			if (null_edid_counter)
-				(*null_edid_counter)++;
-			goto carp;
-		}
-	}
-	if (try == 4)
-		goto carp;
-
-	return edid;
-
-carp:
-	if (connector)
-		connector_bad_edid(connector, edid, 1);
-out:
-	kfree(edid);
-	return NULL;
-}
-
 /**
  * drm_do_get_edid - get EDID data using a custom EDID block read function
  * @connector: connector we're probing
@@ -2138,6 +2100,7 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
 			     read_block_fn read_block,
 			     void *context)
 {
+	enum edid_block_status status;
 	int j, invalid_blocks = 0;
 	struct edid *edid, *new, *override;
 
@@ -2145,10 +2108,31 @@ struct edid *drm_do_get_edid(struct drm_connector *connector,
 	if (override)
 		return override;
 
-	edid = drm_do_get_edid_base_block(connector, read_block, context);
+	edid = kmalloc(EDID_LENGTH, GFP_KERNEL);
 	if (!edid)
 		return NULL;
 
+	status = edid_block_read(edid, 0, read_block, context);
+
+	edid_block_status_print(status, edid, 0);
+
+	if (status == EDID_BLOCK_READ_FAIL)
+		goto out;
+
+	/* FIXME: Clarify what a corrupt EDID actually means. */
+	if (status == EDID_BLOCK_OK || status == EDID_BLOCK_VERSION)
+		connector->edid_corrupt = false;
+	else
+		connector->edid_corrupt = true;
+
+	if (!edid_block_status_valid(status, edid_block_tag(edid))) {
+		if (status == EDID_BLOCK_ZERO)
+			connector->null_edid_counter++;
+
+		connector_bad_edid(connector, edid, 1);
+		goto out;
+	}
+
 	if (edid->extensions == 0)
 		return edid;
 
-- 
2.38.1