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From:   Douglas Anderson <dianders@chromium.org>
To:     Thierry Reding <thierry.reding@gmail.com>,
        Rob Herring <robh+dt@kernel.org>,
        Sam Ravnborg <sam@ravnborg.org>
Cc:     devicetree@vger.kernel.org, Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Linus W <linus.walleij@linaro.org>,
        Daniel Vetter <daniel@ffwll.ch>, linux-arm-msm@vger.kernel.org,
        Steev Klimaszewski <steev@kali.org>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        David Airlie <airlied@linux.ie>,
        dri-devel@lists.freedesktop.org,
        Douglas Anderson <dianders@chromium.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH v4 04/15] drm/edid: Use new encoded panel id style for quirks matching
Date:   Thu,  9 Sep 2021 14:00:20 -0700
Message-Id: <20210909135838.v4.4.I6103ce2b16e5e5a842b14c7022a034712b434609@changeid>
In-Reply-To: <20210909210032.465570-1-dianders@chromium.org>
References: <20210909210032.465570-1-dianders@chromium.org>
MIME-Version: 1.0
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Precedence: bulk

In the patch ("drm/edid: Allow the querying/working with the panel ID
from the EDID") we introduced a different way of working with the
panel ID stored in the EDID. Let's use this new way for the quirks
code.

Advantages of the new style:
* Smaller data structure size. Saves 4 bytes per panel.
* Iterate through quirks structure with just "==" instead of strncmp()
* In-kernel storage is more similar to what's stored in the EDID
  itself making it easier to grok that they are referring to the same
  value.

The quirk table itself is arguably a bit less readable in the new
style but not a ton less and it feels like the above advantages make
up for it.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
This commit is only compile-tested. I don't have any DP panels that
exercise this code. Transition from the old table to the new one was
done with a regexp.

Changes in v4:
- ("Use new encoded panel id style for quirks matching") new for v4.

 drivers/gpu/drm/drm_edid.c | 157 +++++++++++++++++--------------------
 1 file changed, 71 insertions(+), 86 deletions(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index f84e0dd264f4..9b19eee0e1b4 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -100,122 +100,128 @@ struct detailed_mode_closure {
 #define LEVEL_GTF2	2
 #define LEVEL_CVT	3
 
+#define EDID_QUIRK(vend_chr_0, vend_chr_1, vend_chr_2, product_id, _quirks) \
+{ \
+	.panel_id = drm_edid_encode_panel_id(vend_chr_0, vend_chr_1, vend_chr_2, \
+					     product_id), \
+	.quirks = _quirks \
+}
+
 static const struct edid_quirk {
-	char vendor[4];
-	int product_id;
+	u32 panel_id;
 	u32 quirks;
 } edid_quirk_list[] = {
 	/* Acer AL1706 */
-	{ "ACR", 44358, EDID_QUIRK_PREFER_LARGE_60 },
+	EDID_QUIRK('A', 'C', 'R', 44358, EDID_QUIRK_PREFER_LARGE_60),
 	/* Acer F51 */
-	{ "API", 0x7602, EDID_QUIRK_PREFER_LARGE_60 },
+	EDID_QUIRK('A', 'P', 'I', 0x7602, EDID_QUIRK_PREFER_LARGE_60),
 
 	/* AEO model 0 reports 8 bpc, but is a 6 bpc panel */
-	{ "AEO", 0, EDID_QUIRK_FORCE_6BPC },
+	EDID_QUIRK('A', 'E', 'O', 0, EDID_QUIRK_FORCE_6BPC),
 
 	/* BOE model on HP Pavilion 15-n233sl reports 8 bpc, but is a 6 bpc panel */
-	{ "BOE", 0x78b, EDID_QUIRK_FORCE_6BPC },
+	EDID_QUIRK('B', 'O', 'E', 0x78b, EDID_QUIRK_FORCE_6BPC),
 
 	/* CPT panel of Asus UX303LA reports 8 bpc, but is a 6 bpc panel */
-	{ "CPT", 0x17df, EDID_QUIRK_FORCE_6BPC },
+	EDID_QUIRK('C', 'P', 'T', 0x17df, EDID_QUIRK_FORCE_6BPC),
 
 	/* SDC panel of Lenovo B50-80 reports 8 bpc, but is a 6 bpc panel */
-	{ "SDC", 0x3652, EDID_QUIRK_FORCE_6BPC },
+	EDID_QUIRK('S', 'D', 'C', 0x3652, EDID_QUIRK_FORCE_6BPC),
 
 	/* BOE model 0x0771 reports 8 bpc, but is a 6 bpc panel */
-	{ "BOE", 0x0771, EDID_QUIRK_FORCE_6BPC },
+	EDID_QUIRK('B', 'O', 'E', 0x0771, EDID_QUIRK_FORCE_6BPC),
 
 	/* Belinea 10 15 55 */
-	{ "MAX", 1516, EDID_QUIRK_PREFER_LARGE_60 },
-	{ "MAX", 0x77e, EDID_QUIRK_PREFER_LARGE_60 },
+	EDID_QUIRK('M', 'A', 'X', 1516, EDID_QUIRK_PREFER_LARGE_60),
+	EDID_QUIRK('M', 'A', 'X', 0x77e, EDID_QUIRK_PREFER_LARGE_60),
 
 	/* Envision Peripherals, Inc. EN-7100e */
-	{ "EPI", 59264, EDID_QUIRK_135_CLOCK_TOO_HIGH },
+	EDID_QUIRK('E', 'P', 'I', 59264, EDID_QUIRK_135_CLOCK_TOO_HIGH),
 	/* Envision EN2028 */
-	{ "EPI", 8232, EDID_QUIRK_PREFER_LARGE_60 },
+	EDID_QUIRK('E', 'P', 'I', 8232, EDID_QUIRK_PREFER_LARGE_60),
 
 	/* Funai Electronics PM36B */
-	{ "FCM", 13600, EDID_QUIRK_PREFER_LARGE_75 |
-	  EDID_QUIRK_DETAILED_IN_CM },
+	EDID_QUIRK('F', 'C', 'M', 13600, EDID_QUIRK_PREFER_LARGE_75 |
+				       EDID_QUIRK_DETAILED_IN_CM),
 
 	/* LGD panel of HP zBook 17 G2, eDP 10 bpc, but reports unknown bpc */
-	{ "LGD", 764, EDID_QUIRK_FORCE_10BPC },
+	EDID_QUIRK('L', 'G', 'D', 764, EDID_QUIRK_FORCE_10BPC),
 
 	/* LG Philips LCD LP154W01-A5 */
-	{ "LPL", 0, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE },
-	{ "LPL", 0x2a00, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE },
+	EDID_QUIRK('L', 'P', 'L', 0, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE),
+	EDID_QUIRK('L', 'P', 'L', 0x2a00, EDID_QUIRK_DETAILED_USE_MAXIMUM_SIZE),
 
 	/* Samsung SyncMaster 205BW.  Note: irony */
-	{ "SAM", 541, EDID_QUIRK_DETAILED_SYNC_PP },
+	EDID_QUIRK('S', 'A', 'M', 541, EDID_QUIRK_DETAILED_SYNC_PP),
 	/* Samsung SyncMaster 22[5-6]BW */
-	{ "SAM", 596, EDID_QUIRK_PREFER_LARGE_60 },
-	{ "SAM", 638, EDID_QUIRK_PREFER_LARGE_60 },
+	EDID_QUIRK('S', 'A', 'M', 596, EDID_QUIRK_PREFER_LARGE_60),
+	EDID_QUIRK('S', 'A', 'M', 638, EDID_QUIRK_PREFER_LARGE_60),
 
 	/* Sony PVM-2541A does up to 12 bpc, but only reports max 8 bpc */
-	{ "SNY", 0x2541, EDID_QUIRK_FORCE_12BPC },
+	EDID_QUIRK('S', 'N', 'Y', 0x2541, EDID_QUIRK_FORCE_12BPC),
 
 	/* ViewSonic VA2026w */
-	{ "VSC", 5020, EDID_QUIRK_FORCE_REDUCED_BLANKING },
+	EDID_QUIRK('V', 'S', 'C', 5020, EDID_QUIRK_FORCE_REDUCED_BLANKING),
 
 	/* Medion MD 30217 PG */
-	{ "MED", 0x7b8, EDID_QUIRK_PREFER_LARGE_75 },
+	EDID_QUIRK('M', 'E', 'D', 0x7b8, EDID_QUIRK_PREFER_LARGE_75),
 
 	/* Lenovo G50 */
-	{ "SDC", 18514, EDID_QUIRK_FORCE_6BPC },
+	EDID_QUIRK('S', 'D', 'C', 18514, EDID_QUIRK_FORCE_6BPC),
 
 	/* Panel in Samsung NP700G7A-S01PL notebook reports 6bpc */
-	{ "SEC", 0xd033, EDID_QUIRK_FORCE_8BPC },
+	EDID_QUIRK('S', 'E', 'C', 0xd033, EDID_QUIRK_FORCE_8BPC),
 
 	/* Rotel RSX-1058 forwards sink's EDID but only does HDMI 1.1*/
-	{ "ETR", 13896, EDID_QUIRK_FORCE_8BPC },
+	EDID_QUIRK('E', 'T', 'R', 13896, EDID_QUIRK_FORCE_8BPC),
 
 	/* Valve Index Headset */
-	{ "VLV", 0x91a8, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91b0, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91b1, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91b2, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91b3, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91b4, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91b5, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91b6, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91b7, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91b8, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91b9, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91ba, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91bb, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91bc, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91bd, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91be, EDID_QUIRK_NON_DESKTOP },
-	{ "VLV", 0x91bf, EDID_QUIRK_NON_DESKTOP },
+	EDID_QUIRK('V', 'L', 'V', 0x91a8, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91b0, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91b1, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91b2, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91b3, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91b4, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91b5, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91b6, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91b7, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91b8, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91b9, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91ba, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91bb, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91bc, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91bd, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91be, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('V', 'L', 'V', 0x91bf, EDID_QUIRK_NON_DESKTOP),
 
 	/* HTC Vive and Vive Pro VR Headsets */
-	{ "HVR", 0xaa01, EDID_QUIRK_NON_DESKTOP },
-	{ "HVR", 0xaa02, EDID_QUIRK_NON_DESKTOP },
+	EDID_QUIRK('H', 'V', 'R', 0xaa01, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('H', 'V', 'R', 0xaa02, EDID_QUIRK_NON_DESKTOP),
 
 	/* Oculus Rift DK1, DK2, CV1 and Rift S VR Headsets */
-	{ "OVR", 0x0001, EDID_QUIRK_NON_DESKTOP },
-	{ "OVR", 0x0003, EDID_QUIRK_NON_DESKTOP },
-	{ "OVR", 0x0004, EDID_QUIRK_NON_DESKTOP },
-	{ "OVR", 0x0012, EDID_QUIRK_NON_DESKTOP },
+	EDID_QUIRK('O', 'V', 'R', 0x0001, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('O', 'V', 'R', 0x0003, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('O', 'V', 'R', 0x0004, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('O', 'V', 'R', 0x0012, EDID_QUIRK_NON_DESKTOP),
 
 	/* Windows Mixed Reality Headsets */
-	{ "ACR", 0x7fce, EDID_QUIRK_NON_DESKTOP },
-	{ "HPN", 0x3515, EDID_QUIRK_NON_DESKTOP },
-	{ "LEN", 0x0408, EDID_QUIRK_NON_DESKTOP },
-	{ "LEN", 0xb800, EDID_QUIRK_NON_DESKTOP },
-	{ "FUJ", 0x1970, EDID_QUIRK_NON_DESKTOP },
-	{ "DEL", 0x7fce, EDID_QUIRK_NON_DESKTOP },
-	{ "SEC", 0x144a, EDID_QUIRK_NON_DESKTOP },
-	{ "AUS", 0xc102, EDID_QUIRK_NON_DESKTOP },
+	EDID_QUIRK('A', 'C', 'R', 0x7fce, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('H', 'P', 'N', 0x3515, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('L', 'E', 'N', 0x0408, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('L', 'E', 'N', 0xb800, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('F', 'U', 'J', 0x1970, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('D', 'E', 'L', 0x7fce, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('S', 'E', 'C', 0x144a, EDID_QUIRK_NON_DESKTOP),
+	EDID_QUIRK('A', 'U', 'S', 0xc102, EDID_QUIRK_NON_DESKTOP),
 
 	/* Sony PlayStation VR Headset */
-	{ "SNY", 0x0704, EDID_QUIRK_NON_DESKTOP },
+	EDID_QUIRK('S', 'N', 'Y', 0x0704, EDID_QUIRK_NON_DESKTOP),
 
 	/* Sensics VR Headsets */
-	{ "SEN", 0x1019, EDID_QUIRK_NON_DESKTOP },
+	EDID_QUIRK('S', 'E', 'N', 0x1019, EDID_QUIRK_NON_DESKTOP),
 
 	/* OSVR HDK and HDK2 VR Headsets */
-	{ "SVR", 0x1019, EDID_QUIRK_NON_DESKTOP },
+	EDID_QUIRK('S', 'V', 'R', 0x1019, EDID_QUIRK_NON_DESKTOP),
 };
 
 /*
@@ -2090,9 +2096,8 @@ EXPORT_SYMBOL(drm_get_edid);
 static u32 edid_extract_panel_id(const struct edid *edid)
 {
 	/*
-	 * In theory we could try to de-obfuscate this like edid_get_quirks()
-	 * does, but it's easier to just deal with a 32-bit number since then
-	 * it can be compared with "==".
+	 * We represent the ID as a 32-bit number so it can easily be compared
+	 * with "==".
 	 *
 	 * NOTE that we deal with endianness differently for the top half
 	 * of this ID than for the bottom half. The bottom half (the product
@@ -2197,25 +2202,6 @@ EXPORT_SYMBOL(drm_edid_duplicate);
 
 /*** EDID parsing ***/
 
-/**
- * edid_vendor - match a string against EDID's obfuscated vendor field
- * @edid: EDID to match
- * @vendor: vendor string
- *
- * Returns true if @vendor is in @edid, false otherwise
- */
-static bool edid_vendor(const struct edid *edid, const char *vendor)
-{
-	char edid_vendor[3];
-
-	edid_vendor[0] = ((edid->mfg_id[0] & 0x7c) >> 2) + '@';
-	edid_vendor[1] = (((edid->mfg_id[0] & 0x3) << 3) |
-			  ((edid->mfg_id[1] & 0xe0) >> 5)) + '@';
-	edid_vendor[2] = (edid->mfg_id[1] & 0x1f) + '@';
-
-	return !strncmp(edid_vendor, vendor, 3);
-}
-
 /**
  * edid_get_quirks - return quirk flags for a given EDID
  * @edid: EDID to process
@@ -2224,14 +2210,13 @@ static bool edid_vendor(const struct edid *edid, const char *vendor)
  */
 static u32 edid_get_quirks(const struct edid *edid)
 {
+	u32 panel_id = edid_extract_panel_id(edid);
 	const struct edid_quirk *quirk;
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(edid_quirk_list); i++) {
 		quirk = &edid_quirk_list[i];
-
-		if (edid_vendor(edid, quirk->vendor) &&
-		    (EDID_PRODUCT_ID(edid) == quirk->product_id))
+		if (quirk->panel_id == panel_id)
 			return quirk->quirks;
 	}
 
-- 
2.33.0.309.g3052b89438-goog