Re: [PATCH v2 2/3] drm/mediatek: Don't support hdmi connector creation

From: Dafna Hirschfeld
Date: Tue Mar 30 2021 - 05:44:51 EST

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In reply to: Laurent Pinchart: "Re: [PATCH v2 2/3] drm/mediatek: Don't support hdmi connector creation"
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Hi,

On 30.03.21 02:08, Laurent Pinchart wrote:

Hi Dafna,

Thank you for the patch.

On Mon, Mar 29, 2021 at 05:36:31PM +0200, Dafna Hirschfeld wrote:

commit f01195148967 ("drm/mediatek: mtk_dpi: Create connector for bridges")
broke the display support for elm device since mtk_dpi calls
drm_bridge_attach with the flag DRM_BRIDGE_ATTACH_NO_CONNECTOR
while mtk_hdmi does not yet support this flag.

Fix this by accepting DRM_BRIDGE_ATTACH_NO_CONNECTOR in bridge attachment.
Implement the drm_bridge_funcs .detect() and .get_edid() operations, and
call drm_bridge_hpd_notify() to report HPD. This provides the
necessary API to support disabling connector creation.

This patch is inspired by a similar patch for bridge/synopsys/dw-hdmi.c:
commit ec971aaa6775 ("drm: bridge: dw-hdmi: Make connector creation optional")
But with the difference that in mtk-hdmi only the option of not creating
a connector is supported.

Fixes: f01195148967 ("drm/mediatek: mtk_dpi: Create connector for bridges")
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_hdmi.c | 129 ++++++++++------------------
1 file changed, 44 insertions(+), 85 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_hdmi.c b/drivers/gpu/drm/mediatek/mtk_hdmi.c
index f2c810b767ef..1eeb211b1536 100644
--- a/drivers/gpu/drm/mediatek/mtk_hdmi.c
+++ b/drivers/gpu/drm/mediatek/mtk_hdmi.c
@@ -186,11 +186,6 @@ static inline struct mtk_hdmi *hdmi_ctx_from_bridge(struct drm_bridge *b)
return container_of(b, struct mtk_hdmi, bridge);
}
-static inline struct mtk_hdmi *hdmi_ctx_from_conn(struct drm_connector *c)
-{
- return container_of(c, struct mtk_hdmi, conn);
-}
-
static u32 mtk_hdmi_read(struct mtk_hdmi *hdmi, u32 offset)
{
return readl(hdmi->regs + offset);
@@ -1201,48 +1196,30 @@ mtk_hdmi_update_plugged_status(struct mtk_hdmi *hdmi)
connector_status_connected : connector_status_disconnected;
}
-static enum drm_connector_status hdmi_conn_detect(struct drm_connector *conn,
- bool force)
-{
- struct mtk_hdmi *hdmi = hdmi_ctx_from_conn(conn);
- return mtk_hdmi_update_plugged_status(hdmi);
-}
-
-static void hdmi_conn_destroy(struct drm_connector *conn)
+static struct edid *mtk_hdmi_get_edid(struct mtk_hdmi *hdmi,
+ struct drm_connector *connector)
{
- struct mtk_hdmi *hdmi = hdmi_ctx_from_conn(conn);
-
- mtk_cec_set_hpd_event(hdmi->cec_dev, NULL, NULL);
-
- drm_connector_cleanup(conn);
-}
-
-static int mtk_hdmi_conn_get_modes(struct drm_connector *conn)
-{
- struct mtk_hdmi *hdmi = hdmi_ctx_from_conn(conn);
struct edid *edid;
- int ret;
if (!hdmi->ddc_adpt)
- return -ENODEV;
-
- edid = drm_get_edid(conn, hdmi->ddc_adpt);
+ return NULL;
+ edid = drm_get_edid(connector, hdmi->ddc_adpt);
if (!edid)
- return -ENODEV;
-
+ return NULL;
hdmi->dvi_mode = !drm_detect_monitor_audio(edid);
+ return edid;
+}
- drm_connector_update_edid_property(conn, edid);
-
- ret = drm_add_edid_modes(conn, edid);
- kfree(edid);
- return ret;
+static enum drm_connector_status mtk_hdmi_detect(struct mtk_hdmi *hdmi)
+{
+ return mtk_hdmi_update_plugged_status(hdmi);
}
-static int mtk_hdmi_conn_mode_valid(struct drm_connector *conn,
- struct drm_display_mode *mode)
+static int mtk_hdmi_bridge_mode_valid(struct drm_bridge *bridge,
+ const struct drm_display_info *info,
+ const struct drm_display_mode *mode)
{
- struct mtk_hdmi *hdmi = hdmi_ctx_from_conn(conn);
+ struct mtk_hdmi *hdmi = hdmi_ctx_from_bridge(bridge);
struct drm_bridge *next_bridge;
dev_dbg(hdmi->dev, "xres=%d, yres=%d, refresh=%d, intl=%d clock=%d\n",
@@ -1267,74 +1244,50 @@ static int mtk_hdmi_conn_mode_valid(struct drm_connector *conn,
return drm_mode_validate_size(mode, 0x1fff, 0x1fff);
}
-static struct drm_encoder *mtk_hdmi_conn_best_enc(struct drm_connector *conn)
-{
- struct mtk_hdmi *hdmi = hdmi_ctx_from_conn(conn);
-
- return hdmi->bridge.encoder;
-}
-
-static const struct drm_connector_funcs mtk_hdmi_connector_funcs = {
- .detect = hdmi_conn_detect,
- .fill_modes = drm_helper_probe_single_connector_modes,
- .destroy = hdmi_conn_destroy,
- .reset = drm_atomic_helper_connector_reset,
- .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
- .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
-};
-
-static const struct drm_connector_helper_funcs
- mtk_hdmi_connector_helper_funcs = {
- .get_modes = mtk_hdmi_conn_get_modes,
- .mode_valid = mtk_hdmi_conn_mode_valid,
- .best_encoder = mtk_hdmi_conn_best_enc,
-};
-
static void mtk_hdmi_hpd_event(bool hpd, struct device *dev)
{
struct mtk_hdmi *hdmi = dev_get_drvdata(dev);
- if (hdmi && hdmi->bridge.encoder && hdmi->bridge.encoder->dev)
+ if (hdmi && hdmi->bridge.encoder && hdmi->bridge.encoder->dev) {
+ static enum drm_connector_status status;
+
+ status = mtk_hdmi_detect(hdmi);
drm_helper_hpd_irq_event(hdmi->bridge.encoder->dev);

I think you can drop this, as drm_bridge_connector_hpd_cb() calls
drm_kms_helper_hotplug_event().

I see that drm_kms_helper_hotplug_event is called from drm_bridge_connector_hpd_cb,
which is set as a birdge's 'hpd_cb' when calling drm_bridge_connector_enable_hpd,
but mkt_dpi does not call this funcion for the drm_bridge_connector.

I also wonder why bridges have both 'hpd_cb' and a function 'hpd_notify'.
It seems that both are called upon hot-plug event.
It is also confusing that the function drm_bridge_hpd_notify calls the 'hpd_cb'
and not the 'hpd_notfiy'. I can send a patch to change the name to 'drm_bridge_hpd_cb'

Thanks,
Dafna

+ drm_bridge_hpd_notify(&hdmi->bridge, status);
+ }
}
/*
* Bridge callbacks
*/
+static enum drm_connector_status mtk_hdmi_bridge_detect(struct drm_bridge *bridge)
+{
+ struct mtk_hdmi *hdmi = hdmi_ctx_from_bridge(bridge);
+
+ return mtk_hdmi_detect(hdmi);
+}
+
+static struct edid *mtk_hdmi_bridge_get_edid(struct drm_bridge *bridge,
+ struct drm_connector *connector)
+{
+ struct mtk_hdmi *hdmi = hdmi_ctx_from_bridge(bridge);
+
+ return mtk_hdmi_get_edid(hdmi, connector);

As mtk_hdmi_get_edid() is only called here, you could inline it in this
function. Up to you.

+}
+
static int mtk_hdmi_bridge_attach(struct drm_bridge *bridge,
enum drm_bridge_attach_flags flags)
{
struct mtk_hdmi *hdmi = hdmi_ctx_from_bridge(bridge);
int ret;
- if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
- DRM_ERROR("Fix bridge driver to make connector optional!");
+ if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
+ DRM_ERROR("%s: The flag DRM_BRIDGE_ATTACH_NO_CONNECTOR must be supplied\n",
+ __func__);
return -EINVAL;
}
- ret = drm_connector_init_with_ddc(bridge->encoder->dev, &hdmi->conn,
- &mtk_hdmi_connector_funcs,
- DRM_MODE_CONNECTOR_HDMIA,
- hdmi->ddc_adpt);
- if (ret) {
- dev_err(hdmi->dev, "Failed to initialize connector: %d\n", ret);
- return ret;
- }
- drm_connector_helper_add(&hdmi->conn, &mtk_hdmi_connector_helper_funcs);
-
- hdmi->conn.polled = DRM_CONNECTOR_POLL_HPD;
- hdmi->conn.interlace_allowed = true;
- hdmi->conn.doublescan_allowed = false;
-
- ret = drm_connector_attach_encoder(&hdmi->conn,
- bridge->encoder);
- if (ret) {
- dev_err(hdmi->dev,
- "Failed to attach connector to encoder: %d\n", ret);
- return ret;
- }
-
if (hdmi->next_bridge) {
ret = drm_bridge_attach(bridge->encoder, hdmi->next_bridge,
bridge, flags);
@@ -1444,6 +1397,7 @@ static void mtk_hdmi_bridge_atomic_enable(struct drm_bridge *bridge,
}
static const struct drm_bridge_funcs mtk_hdmi_bridge_funcs = {
+ .mode_valid = mtk_hdmi_bridge_mode_valid,
.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
.atomic_reset = drm_atomic_helper_bridge_reset,
@@ -1454,6 +1408,8 @@ static const struct drm_bridge_funcs mtk_hdmi_bridge_funcs = {
.mode_set = mtk_hdmi_bridge_mode_set,
.atomic_pre_enable = mtk_hdmi_bridge_atomic_pre_enable,
.atomic_enable = mtk_hdmi_bridge_atomic_enable,
+ .detect = mtk_hdmi_bridge_detect,
+ .get_edid = mtk_hdmi_bridge_get_edid,
};
static int mtk_hdmi_dt_parse_pdata(struct mtk_hdmi *hdmi,
@@ -1762,6 +1718,9 @@ static int mtk_drm_hdmi_probe(struct platform_device *pdev)
hdmi->bridge.funcs = &mtk_hdmi_bridge_funcs;
hdmi->bridge.of_node = pdev->dev.of_node;
+ hdmi->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID
+ | DRM_BRIDGE_OP_HPD;

Nitpicking, I'd align the | to the =.

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

+ hdmi->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
drm_bridge_add(&hdmi->bridge);
ret = mtk_hdmi_clk_enable_audio(hdmi);

Next message: Quentin Perret: "Re: [PATCH] sched/fair: use signed long when compute energy delta in eas"
Previous message: Robert Foss: "Re: [PATCH v6 09/14] drm/bridge: imx: Add i.MX8qxp pixel link to DPI support"
In reply to: Laurent Pinchart: "Re: [PATCH v2 2/3] drm/mediatek: Don't support hdmi connector creation"
Next in thread: Dafna Hirschfeld: "[PATCH v2 1/3] drm/mediatek: Switch the hdmi bridge ops to the atomic versions"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]