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From:   Maciej Purski <m.purski@samsung.com>
To:     dri-devel@lists.freedesktop.org
Cc:     Archit Taneja <architt@codeaurora.org>,
        Andrzej Hajda <a.hajda@samsung.com>,
        Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
        David Airlie <airlied@linux.ie>,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        linux-kernel@vger.kernel.org, Maciej Purski <m.purski@samsung.com>
Subject: [PATCH v2] drm/bridge/sii8620: fix HDMI cable connection to dongle
Date:   Tue, 23 Jan 2018 12:13:16 +0100
Message-id: <1516705996-8928-1-git-send-email-m.purski@samsung.com>
CMS-TYPE: 201P
References: <CGME20180123111328eucas1p2f9b9aa506e5edda012ab8f40230f6d28@eucas1p2.samsung.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

MHL bridge is usually connected to TV via MHL dongle. Currently plugging
HDMI cable to dongle is handled improperly.

Fix it by splitting connecting of a dongle and a HDMI cable. The driver
should now handle unplugging a sink from a dongle and plugging a
different sink with new edid.

Tested on MHL1, MHL2 and MHL3 using various vendors' dongles both in
DVI and HDMI mode.

Signed-off-by: Maciej Purski <m.purski@samsung.com>

---
Changes in v2:
- handle MHL1 and MHL2 initialization sequence
- rename hpd_plugged() function to identify_sink(), as it is now used
  in different contexts
- fix commit message
---
 drivers/gpu/drm/bridge/sil-sii8620.c | 64 +++++++++++++++++++++++-------------
 1 file changed, 41 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/bridge/sil-sii8620.c b/drivers/gpu/drm/bridge/sil-sii8620.c
index 46ccceb..5168783 100644
--- a/drivers/gpu/drm/bridge/sil-sii8620.c
+++ b/drivers/gpu/drm/bridge/sil-sii8620.c
@@ -78,6 +78,9 @@ struct sii8620 {
 	u8 devcap[MHL_DCAP_SIZE];
 	u8 xdevcap[MHL_XDC_SIZE];
 	u8 avif[HDMI_INFOFRAME_SIZE(AVI)];
+	bool feature_complete;
+	bool devcap_read;
+	bool sink_detected;
 	struct edid *edid;
 	unsigned int gen2_write_burst:1;
 	enum sii8620_mt_state mt_state;
@@ -470,7 +473,7 @@ static void sii8620_update_array(u8 *dst, u8 *src, int count)
 	}
 }
 
-static void sii8620_sink_detected(struct sii8620 *ctx, int ret)
+static void sii8620_identify_sink(struct sii8620 *ctx)
 {
 	static const char * const sink_str[] = {
 		[SINK_NONE] = "NONE",
@@ -481,7 +484,7 @@ static void sii8620_sink_detected(struct sii8620 *ctx, int ret)
 	char sink_name[20];
 	struct device *dev = ctx->dev;
 
-	if (ret < 0)
+	if (!ctx->sink_detected || !ctx->devcap_read)
 		return;
 
 	sii8620_fetch_edid(ctx);
@@ -490,6 +493,7 @@ static void sii8620_sink_detected(struct sii8620 *ctx, int ret)
 		sii8620_mhl_disconnected(ctx);
 		return;
 	}
+	sii8620_set_upstream_edid(ctx);
 
 	if (drm_detect_hdmi_monitor(ctx->edid))
 		ctx->sink_type = SINK_HDMI;
@@ -502,15 +506,6 @@ static void sii8620_sink_detected(struct sii8620 *ctx, int ret)
 		 sink_str[ctx->sink_type], sink_name);
 }
 
-static void sii8620_edid_read(struct sii8620 *ctx, int ret)
-{
-	if (ret < 0)
-		return;
-
-	sii8620_set_upstream_edid(ctx);
-	sii8620_enable_hpd(ctx);
-}
-
 static void sii8620_mr_devcap(struct sii8620 *ctx)
 {
 	u8 dcap[MHL_DCAP_SIZE];
@@ -526,6 +521,8 @@ static void sii8620_mr_devcap(struct sii8620 *ctx)
 		 dcap[MHL_DCAP_ADOPTER_ID_H], dcap[MHL_DCAP_ADOPTER_ID_L],
 		 dcap[MHL_DCAP_DEVICE_ID_H], dcap[MHL_DCAP_DEVICE_ID_L]);
 	sii8620_update_array(ctx->devcap, dcap, MHL_DCAP_SIZE);
+	ctx->devcap_read = true;
+	sii8620_identify_sink(ctx);
 }
 
 static void sii8620_mr_xdevcap(struct sii8620 *ctx)
@@ -1491,6 +1488,16 @@ static void sii8620_set_mode(struct sii8620 *ctx, enum sii8620_mode mode)
 	);
 }
 
+static void sii8620_hpd_unplugged(struct sii8620 *ctx)
+{
+	sii8620_disable_hpd(ctx);
+	ctx->sink_type = SINK_NONE;
+	ctx->sink_detected = false;
+	ctx->feature_complete = false;
+	kfree(ctx->edid);
+	ctx->edid = NULL;
+}
+
 static void sii8620_disconnect(struct sii8620 *ctx)
 {
 	sii8620_disable_gen2_write_burst(ctx);
@@ -1518,7 +1525,7 @@ static void sii8620_disconnect(struct sii8620 *ctx)
 		REG_MHL_DP_CTL6, 0x2A,
 		REG_MHL_DP_CTL7, 0x03
 	);
-	sii8620_disable_hpd(ctx);
+	sii8620_hpd_unplugged(ctx);
 	sii8620_write_seq_static(ctx,
 		REG_M3_CTRL, VAL_M3_CTRL_MHL3_VALUE,
 		REG_MHL_COC_CTL1, 0x07,
@@ -1566,10 +1573,8 @@ static void sii8620_disconnect(struct sii8620 *ctx)
 	memset(ctx->xstat, 0, sizeof(ctx->xstat));
 	memset(ctx->devcap, 0, sizeof(ctx->devcap));
 	memset(ctx->xdevcap, 0, sizeof(ctx->xdevcap));
+	ctx->devcap_read = false;
 	ctx->cbus_status = 0;
-	ctx->sink_type = SINK_NONE;
-	kfree(ctx->edid);
-	ctx->edid = NULL;
 	sii8620_mt_cleanup(ctx);
 }
 
@@ -1660,9 +1665,6 @@ static void sii8620_status_changed_path(struct sii8620 *ctx)
 		sii8620_mt_write_stat(ctx, MHL_DST_REG(LINK_MODE),
 				      MHL_DST_LM_CLK_MODE_NORMAL
 				      | MHL_DST_LM_PATH_ENABLED);
-		if (!sii8620_is_mhl3(ctx))
-			sii8620_mt_read_devcap(ctx, false);
-		sii8620_mt_set_cont(ctx, sii8620_sink_detected);
 	} else {
 		sii8620_mt_write_stat(ctx, MHL_DST_REG(LINK_MODE),
 				      MHL_DST_LM_CLK_MODE_NORMAL);
@@ -1679,9 +1681,13 @@ static void sii8620_msc_mr_write_stat(struct sii8620 *ctx)
 	sii8620_update_array(ctx->stat, st, MHL_DST_SIZE);
 	sii8620_update_array(ctx->xstat, xst, MHL_XDS_SIZE);
 
-	if (ctx->stat[MHL_DST_CONNECTED_RDY] & MHL_DST_CONN_DCAP_RDY)
+	if (ctx->stat[MHL_DST_CONNECTED_RDY] & st[MHL_DST_CONNECTED_RDY] & MHL_DST_CONN_DCAP_RDY) {
 		sii8620_status_dcap_ready(ctx);
 
+		if (!sii8620_is_mhl3(ctx))
+			sii8620_mt_read_devcap(ctx, false);
+	}
+
 	if (st[MHL_DST_LINK_MODE] & MHL_DST_LM_PATH_ENABLED)
 		sii8620_status_changed_path(ctx);
 }
@@ -1765,8 +1771,11 @@ static void sii8620_msc_mr_set_int(struct sii8620 *ctx)
 	}
 	if (ints[MHL_INT_RCHANGE] & MHL_INT_RC_FEAT_REQ)
 		sii8620_send_features(ctx);
-	if (ints[MHL_INT_RCHANGE] & MHL_INT_RC_FEAT_COMPLETE)
-		sii8620_edid_read(ctx, 0);
+	if (ints[MHL_INT_RCHANGE] & MHL_INT_RC_FEAT_COMPLETE) {
+		ctx->feature_complete = true;
+		if (ctx->edid)
+			sii8620_enable_hpd(ctx);
+	}
 }
 
 static struct sii8620_mt_msg *sii8620_msc_msg_first(struct sii8620 *ctx)
@@ -1841,6 +1850,15 @@ static void sii8620_irq_msc(struct sii8620 *ctx)
 	if (stat & BIT_CBUS_MSC_MR_WRITE_STAT)
 		sii8620_msc_mr_write_stat(ctx);
 
+	if (stat & BIT_CBUS_HPD_CHG) {
+		if (ctx->cbus_status & BIT_CBUS_STATUS_CBUS_HPD) {
+			ctx->sink_detected = true;
+			sii8620_identify_sink(ctx);
+		} else {
+			sii8620_hpd_unplugged(ctx);
+		}
+	}
+
 	if (stat & BIT_CBUS_MSC_MR_SET_INT)
 		sii8620_msc_mr_set_int(ctx);
 
@@ -1952,11 +1970,11 @@ static void sii8620_irq_ddc(struct sii8620 *ctx)
 
 	if (stat & BIT_DDC_CMD_DONE) {
 		sii8620_write(ctx, REG_INTR3_MASK, 0);
-		if (sii8620_is_mhl3(ctx))
+		if (sii8620_is_mhl3(ctx) && !ctx->feature_complete)
 			sii8620_mt_set_int(ctx, MHL_INT_REG(RCHANGE),
 					   MHL_INT_RC_FEAT_REQ);
 		else
-			sii8620_edid_read(ctx, 0);
+			sii8620_enable_hpd(ctx);
 	}
 	sii8620_write(ctx, REG_INTR3, stat);
 }
-- 
2.7.4