drm/dp: Revert "drm/dp: Introduce EDID-based quirks"

This reverts commit 0883ce8146ed6074c76399f4e70dbed788582e12. Originally
these quirks were added because of the issues with using the eDP
backlight interfaces on certain laptop panels, which made it impossible
to properly probe for DPCD backlight support without having a whitelist
for panels that we know have working VESA backlight control interfaces
over DPCD. As well, it should be noted it was impossible to use the
normal sink OUI for recognizing these panels as none of them actually
filled out their OUIs, hence needing to resort to checking EDIDs.

At the time we weren't really sure why certain panels had issues with
DPCD backlight controls, but we eventually figured out that there was a
second interface that these problematic laptop panels actually did work
with and advertise properly: Intel's proprietary backlight interface for
HDR panels. So far the testing we've done hasn't brought any panels to
light that advertise this interface and don't support it properly, which
means we finally have a real solution to this problem.

As a result, we now have no need for the force DPCD backlight quirk, and
furthermore this also removes the need for any kind of EDID quirk
checking in DRM. So, let's just revert it for now since we were the only
driver using this.

v3:
* Rebase
v2:
* Fix indenting error picked up by checkpatch in
  intel_edp_init_connector()

Signed-off-by: Lyude Paul <lyude@redhat.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Cc: thaytan@noraisin.net
Cc: Vasily Khoruzhick <anarsoul@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210114221709.2261452-6-lyude@redhat.com

1 files changed, 1 insertions, 82 deletions

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 3ecde451f523..19dbdeb581cb 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -1236,7 +1236,7 @@ bool drm_dp_read_sink_count_cap(struct drm_connector *connector,
 	return connector->connector_type != DRM_MODE_CONNECTOR_eDP &&
 		dpcd[DP_DPCD_REV] >= DP_DPCD_REV_11 &&
 		dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT &&
-		!drm_dp_has_quirk(desc, 0, DP_DPCD_QUIRK_NO_SINK_COUNT);
+		!drm_dp_has_quirk(desc, DP_DPCD_QUIRK_NO_SINK_COUNT);
 }
 EXPORT_SYMBOL(drm_dp_read_sink_count_cap);
 
@@ -1957,87 +1957,6 @@ drm_dp_get_quirks(const struct drm_dp_dpcd_ident *ident, bool is_branch)
 #undef DEVICE_ID_ANY
 #undef DEVICE_ID
 
-struct edid_quirk {
-	u8 mfg_id[2];
-	u8 prod_id[2];
-	u32 quirks;
-};
-
-#define MFG(first, second) { (first), (second) }
-#define PROD_ID(first, second) { (first), (second) }
-
-/*
- * Some devices have unreliable OUIDs where they don't set the device ID
- * correctly, and as a result we need to use the EDID for finding additional
- * DP quirks in such cases.
- */
-static const struct edid_quirk edid_quirk_list[] = {
-	/* Optional 4K AMOLED panel in the ThinkPad X1 Extreme 2nd Generation
-	 * only supports DPCD backlight controls
-	 */
-	{ MFG(0x4c, 0x83), PROD_ID(0x41, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
-	/*
-	 * Some Dell CML 2020 systems have panels support both AUX and PWM
-	 * backlight control, and some only support AUX backlight control. All
-	 * said panels start up in AUX mode by default, and we don't have any
-	 * support for disabling HDR mode on these panels which would be
-	 * required to switch to PWM backlight control mode (plus, I'm not
-	 * even sure we want PWM backlight controls over DPCD backlight
-	 * controls anyway...). Until we have a better way of detecting these,
-	 * force DPCD backlight mode on all of them.
-	 */
-	{ MFG(0x06, 0xaf), PROD_ID(0x9b, 0x32), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
-	{ MFG(0x06, 0xaf), PROD_ID(0xeb, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
-	{ MFG(0x4d, 0x10), PROD_ID(0xc7, 0x14), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
-	{ MFG(0x4d, 0x10), PROD_ID(0xe6, 0x14), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
-	{ MFG(0x4c, 0x83), PROD_ID(0x47, 0x41), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
-	{ MFG(0x09, 0xe5), PROD_ID(0xde, 0x08), BIT(DP_QUIRK_FORCE_DPCD_BACKLIGHT) },
-};
-
-#undef MFG
-#undef PROD_ID
-
-/**
- * drm_dp_get_edid_quirks() - Check the EDID of a DP device to find additional
- * DP-specific quirks
- * @edid: The EDID to check
- *
- * While OUIDs are meant to be used to recognize a DisplayPort device, a lot
- * of manufacturers don't seem to like following standards and neglect to fill
- * the dev-ID in, making it impossible to only use OUIDs for determining
- * quirks in some cases. This function can be used to check the EDID and look
- * up any additional DP quirks. The bits returned by this function correspond
- * to the quirk bits in &drm_dp_quirk.
- *
- * Returns: a bitmask of quirks, if any. The driver can check this using
- * drm_dp_has_quirk().
- */
-u32 drm_dp_get_edid_quirks(const struct edid *edid)
-{
-	const struct edid_quirk *quirk;
-	u32 quirks = 0;
-	int i;
-
-	if (!edid)
-		return 0;
-
-	for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) {
-		quirk = &edid_quirk_list[i];
-		if (memcmp(quirk->mfg_id, edid->mfg_id,
-			   sizeof(edid->mfg_id)) == 0 &&
-		    memcmp(quirk->prod_id, edid->prod_code,
-			   sizeof(edid->prod_code)) == 0)
-			quirks |= quirk->quirks;
-	}
-
-	DRM_DEBUG_KMS("DP sink: EDID mfg %*phD prod-ID %*phD quirks: 0x%04x\n",
-		      (int)sizeof(edid->mfg_id), edid->mfg_id,
-		      (int)sizeof(edid->prod_code), edid->prod_code, quirks);
-
-	return quirks;
-}
-EXPORT_SYMBOL(drm_dp_get_edid_quirks);
-
 /**
  * drm_dp_read_desc - read sink/branch descriptor from DPCD
  * @aux: DisplayPort AUX channel