[PATCH v2] drm/bridge/sii8620: fix HDMI cable connection to dongle

From: Maciej Purski
Date: Tue Jan 23 2018 - 06:13:38 EST


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@xxxxxxxxxxx>

---
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