[PATCH v8 drm-dp 0/4] Fix hibmc driver bugs

[PATCH v8 drm-dp 0/4] Fix hibmc driver bugs

[Yongbang Shi]

From: Baihan Li <libaihan@huawei.com>

There are some bugfix for hibmc-drm driver.
---
ChangeLog:
v7 -> v8:
  - fix build errors reported by kernel test robot <lkp@intel.com>
    Closes: https://lore.kernel.org/oe-kbuild-all/202509241625.o4mNleVb-lkp@intel.com/
v6 -> v7:
  - add the check about branch devices, suggested by Dmitry Baryshkov.
v5 -> v6:
  - use HPD status in DP detect_ctx(), suggested by Dmitry Baryshkov.
v4 -> v5:
  - Because some of patches are applied, this series only contains the rest of them.
  - fix the commit and DP detect_ctx(), suggested by Dmitry Baryshkov.
  - fix bugfix commit ID, suggested by Dmitry Baryshkov.
  - remove the 08/11 patch, I'll add in next series.
  - combined 9 and 11 patch together, suggested by Dmitry Baryshkov.
v3 -> v4:
  - remove link training process in hibmc_dp_detect(), suggested by Dmitry Baryshkov.
  - remove if (dev->registered), suggested by Dmitry Baryshkov.
  - remove non-related changes, suggested by Dmitry Baryshkov.
  - Remove the clock check, suggested by Dmitry Baryshkov.
  - ( I'll add them in next series after redesigning this part)
  - add KVM edid in commit message, suggested by Dmitry Baryshkov.
  - fix magic values, suggested by Dmitry Baryshkov.
  - fix the commit subjects, suggested by Dmitry Baryshkov.
v2 -> v3:
  - fix hibmc_connector_get_modes() and hibmc_vdac_detect() to realize BMC KVM, suggested by Dmitry Baryshkov.
  - fix the issue commit ID, suggested by Dmitry Baryshkov.
  - split into 2 commits, suggested by Dmitry Baryshkov.
  - add more comments in commit log, suggested by Dmitry Baryshkov.
---

Baihan Li (4):
  drm/hisilicon/hibmc: fix dp probabilistical detect errors after HPD
    irq
  drm/hisilicon/hibmc: add dp mode valid check
  drm/hisilicon/hibmc: fix no showing problem with loading hibmc
    manually
  drm/hisilicon/hibmc: Adding reset colorbar cfg in dp init.

 drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h  |  4 ++
 .../gpu/drm/hisilicon/hibmc/dp/dp_config.h    |  2 +
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c    | 31 ++++++++-
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h    |  8 +++
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h   |  3 +
 .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c    | 67 ++++++++++++++++++-
 6 files changed, 111 insertions(+), 4 deletions(-)

-- 
2.33.0

[PATCH v8 drm-dp 1/4] drm/hisilicon/hibmc: fix dp probabilistical detect errors after HPD irq

[Yongbang Shi]

From: Baihan Li <libaihan@huawei.com>

The issue is that drm_connector_helper_detect_from_ddc() returns wrong
status when plugging or unplugging the monitor. Use HPD pin status in
DP's detect_ctx() for real physcal monitor in/out, and implementation
a complete DP detection including read DPCD, check if it's a branch
device and its sink count for different situations.

Fixes: 3c7623fb5bb6 ("drm/hisilicon/hibmc: Enable this hot plug detect of irq feature")
Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
---
ChangeLog:
v7 -> v8:
  - fix build errors reported by kernel test robot <lkp@intel.com>
    Closes: https://lore.kernel.org/oe-kbuild-all/202509241625.o4mNleVb-lkp@intel.com/
v6 -> v7:
  - add the check about branch devices, suggested by Dmitry Baryshkov.
v5 -> v6:
  - use HPD status in DP detect_ctx(), suggested by Dmitry Baryshkov.
v4 -> v5:
  - fix the commit message and DP detect_ctx(), suggested by Dmitry Baryshkov.
---
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h  |  4 ++
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c    | 12 +++++
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h    |  6 +++
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h   |  3 ++
 .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c    | 48 ++++++++++++++++++-
 5 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
index 4add05c7f161..f9ee7ebfec55 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
@@ -40,6 +40,10 @@ struct hibmc_dp_dev {
 	struct mutex lock; /* protects concurrent RW in hibmc_dp_reg_write_field() */
 	struct hibmc_dp_link link;
 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
+	u8 downstream_ports[DP_MAX_DOWNSTREAM_PORTS];
+	struct drm_dp_desc desc;
+	bool is_branch;
+	int hpd_status;
 	void __iomem *serdes_base;
 };
 
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
index 8f0daec7d174..bd3d73075629 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
@@ -2,6 +2,7 @@
 // Copyright (c) 2024 Hisilicon Limited.
 
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/delay.h>
 #include "dp_config.h"
 #include "dp_comm.h"
@@ -305,3 +306,14 @@ void hibmc_dp_set_cbar(struct hibmc_dp *dp, const struct hibmc_dp_cbar_cfg *cfg)
 	hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_COLOR_BAR_CTRL, BIT(0), cfg->enable);
 	writel(HIBMC_DP_SYNC_EN_MASK, dp_dev->base + HIBMC_DP_TIMING_SYNC_CTRL);
 }
+
+void hibmc_dp_update_hpd_status(struct hibmc_dp *dp)
+{
+	int status;
+
+	readl_poll_timeout(dp->dp_dev->base + HIBMC_DP_HPD_STATUS, status,
+			   FIELD_GET(HIBMC_DP_HPD_CUR_STATE, status) != dp->dp_dev->hpd_status,
+			   1000, 100000); /* DP spec says 100ms */
+
+	dp->dp_dev->hpd_status = FIELD_GET(HIBMC_DP_HPD_CUR_STATE, status);
+}
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
index 665f5b166dfb..1e2214aece6a 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
@@ -14,6 +14,11 @@
 
 struct hibmc_dp_dev;
 
+enum hibmc_hpd_status {
+	HIBMC_HPD_OUT,
+	HIBMC_HPD_IN,
+};
+
 enum hibmc_dp_cbar_pattern {
 	CBAR_COLOR_BAR,
 	CBAR_WHITE,
@@ -60,5 +65,6 @@ void hibmc_dp_reset_link(struct hibmc_dp *dp);
 void hibmc_dp_hpd_cfg(struct hibmc_dp *dp);
 void hibmc_dp_enable_int(struct hibmc_dp *dp);
 void hibmc_dp_disable_int(struct hibmc_dp *dp);
+void hibmc_dp_update_hpd_status(struct hibmc_dp *dp);
 
 #endif
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
index 394b1e933c3a..64306abcd986 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
@@ -24,6 +24,9 @@
 #define HIBMC_DP_CFG_AUX_READY_DATA_BYTE	GENMASK(16, 12)
 #define HIBMC_DP_CFG_AUX			GENMASK(24, 17)
 
+#define HIBMC_DP_HPD_STATUS			0x98
+#define HIBMC_DP_HPD_CUR_STATE		GENMASK(7, 4)
+
 #define HIBMC_DP_PHYIF_CTRL0			0xa0
 #define HIBMC_DP_CFG_SCRAMBLE_EN		BIT(0)
 #define HIBMC_DP_CFG_PAT_SEL			GENMASK(7, 4)
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
index d06832e62e96..dad77fb61b99 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
@@ -12,6 +12,7 @@
 
 #include "hibmc_drm_drv.h"
 #include "dp/dp_hw.h"
+#include "dp/dp_comm.h"
 
 #define DP_MASKED_SINK_HPD_PLUG_INT	BIT(2)
 
@@ -31,12 +32,53 @@ static int hibmc_dp_connector_get_modes(struct drm_connector *connector)
 	return count;
 }
 
+static bool hibmc_dp_get_dpcd(struct hibmc_dp_dev *dp_dev)
+{
+	int ret;
+
+	ret = drm_dp_read_dpcd_caps(dp_dev->aux, dp_dev->dpcd);
+	if (ret)
+		return false;
+
+	dp_dev->is_branch = drm_dp_is_branch(dp_dev->dpcd);
+
+	ret = drm_dp_read_desc(dp_dev->aux, &dp_dev->desc, dp_dev->is_branch);
+	if (ret)
+		return false;
+
+	ret = drm_dp_read_downstream_info(dp_dev->aux, dp_dev->dpcd, dp_dev->downstream_ports);
+	if (ret)
+		return false;
+
+	return true;
+}
+
 static int hibmc_dp_detect(struct drm_connector *connector,
 			   struct drm_modeset_acquire_ctx *ctx, bool force)
 {
-	mdelay(200);
+	struct hibmc_dp *dp = to_hibmc_dp(connector);
+	struct hibmc_dp_dev *dp_dev = dp->dp_dev;
+	int ret;
+
+	if (dp->irq_status) {
+		if (dp_dev->hpd_status != HIBMC_HPD_IN)
+			return connector_status_disconnected;
+	}
 
-	return drm_connector_helper_detect_from_ddc(connector, ctx, force);
+	if (!hibmc_dp_get_dpcd(dp_dev))
+		return connector_status_disconnected;
+
+	if (!dp_dev->is_branch)
+		return connector_status_connected;
+
+	if (drm_dp_read_sink_count_cap(connector, dp_dev->dpcd, &dp_dev->desc) &&
+	    dp_dev->downstream_ports[0] & DP_DS_PORT_HPD) {
+		ret = drm_dp_read_sink_count(dp_dev->aux);
+		if (ret > 0)
+			return connector_status_connected;
+	}
+
+	return connector_status_disconnected;
 }
 
 static const struct drm_connector_helper_funcs hibmc_dp_conn_helper_funcs = {
@@ -128,6 +170,8 @@ irqreturn_t hibmc_dp_hpd_isr(int irq, void *arg)
 		hibmc_dp_reset_link(&priv->dp);
 	}
 
+	hibmc_dp_update_hpd_status(&priv->dp);
+
 	if (dev->registered)
 		drm_connector_helper_hpd_irq_event(&priv->dp.connector);
 
-- 
2.33.0

[PATCH v8 drm-dp 2/4] drm/hisilicon/hibmc: add dp mode valid check

[Yongbang Shi]

From: Baihan Li <libaihan@huawei.com>

If DP is connected, check the DP BW in mode_valid_ctx() to ensure
that DP's link rate supports high-resolution data transmission.

Fixes: 0ab6ea261c1f ("drm/hisilicon/hibmc: add dp module in hibmc")
Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
ChangeLog:
v4 -> v5:
  - fix bugfix commit ID, suggested by Dmitry Baryshkov.
---
 .../gpu/drm/hisilicon/hibmc/dp/dp_config.h    |  2 ++
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c    | 10 ++++++++++
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h    |  2 ++
 .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c    | 19 +++++++++++++++++++
 4 files changed, 33 insertions(+)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
index 08f9e1caf7fc..efb30a758475 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
@@ -17,5 +17,7 @@
 #define HIBMC_DP_LINK_RATE_CAL		27
 #define HIBMC_DP_SYNC_DELAY(lanes)	((lanes) == 0x2 ? 86 : 46)
 #define HIBMC_DP_INT_ENABLE		0xc
+/* HIBMC_DP_LINK_RATE_CAL * 10000 * 80% = 216000 */
+#define DP_MODE_VALI_CAL		216000
 
 #endif
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
index bd3d73075629..23df0d5228ca 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
@@ -264,6 +264,16 @@ void hibmc_dp_reset_link(struct hibmc_dp *dp)
 	dp->dp_dev->link.status.channel_equalized = false;
 }
 
+u8 hibmc_dp_get_link_rate(struct hibmc_dp *dp)
+{
+	return dp->dp_dev->link.cap.link_rate;
+}
+
+u8 hibmc_dp_get_lanes(struct hibmc_dp *dp)
+{
+	return dp->dp_dev->link.cap.lanes;
+}
+
 static const struct hibmc_dp_color_raw g_rgb_raw[] = {
 	{CBAR_COLOR_BAR, 0x000, 0x000, 0x000},
 	{CBAR_WHITE,     0xfff, 0xfff, 0xfff},
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
index 1e2214aece6a..e0a01e0f8a5f 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
@@ -66,5 +66,7 @@ void hibmc_dp_hpd_cfg(struct hibmc_dp *dp);
 void hibmc_dp_enable_int(struct hibmc_dp *dp);
 void hibmc_dp_disable_int(struct hibmc_dp *dp);
 void hibmc_dp_update_hpd_status(struct hibmc_dp *dp);
+u8 hibmc_dp_get_link_rate(struct hibmc_dp *dp);
+u8 hibmc_dp_get_lanes(struct hibmc_dp *dp);
 
 #endif
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
index dad77fb61b99..f3674f51d09f 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
@@ -13,6 +13,7 @@
 #include "hibmc_drm_drv.h"
 #include "dp/dp_hw.h"
 #include "dp/dp_comm.h"
+#include "dp/dp_config.h"
 
 #define DP_MASKED_SINK_HPD_PLUG_INT	BIT(2)
 
@@ -81,9 +82,27 @@ static int hibmc_dp_detect(struct drm_connector *connector,
 	return connector_status_disconnected;
 }
 
+static int hibmc_dp_mode_valid(struct drm_connector *connector,
+			       const struct drm_display_mode *mode,
+			       struct drm_modeset_acquire_ctx *ctx,
+			       enum drm_mode_status *status)
+{
+	struct hibmc_dp *dp = to_hibmc_dp(connector);
+	u64 cur_val, max_val;
+
+	/* check DP link BW */
+	cur_val = (u64)mode->clock * HIBMC_DP_BPP;
+	max_val = (u64)hibmc_dp_get_link_rate(dp) * DP_MODE_VALI_CAL * hibmc_dp_get_lanes(dp);
+
+	*status = cur_val > max_val ? MODE_CLOCK_HIGH : MODE_OK;
+
+	return 0;
+}
+
 static const struct drm_connector_helper_funcs hibmc_dp_conn_helper_funcs = {
 	.get_modes = hibmc_dp_connector_get_modes,
 	.detect_ctx = hibmc_dp_detect,
+	.mode_valid_ctx = hibmc_dp_mode_valid,
 };
 
 static int hibmc_dp_late_register(struct drm_connector *connector)
-- 
2.33.0

[PATCH v8 drm-dp 3/4] drm/hisilicon/hibmc: fix no showing problem with loading hibmc manually

[Yongbang Shi]

From: Baihan Li <libaihan@huawei.com>

When using command rmmod and insmod, there is no showing in second time
insmoding. Because DP controller won't send HPD signals, if connection
doesn't change or controller isn't reset. So add reset before unreset
in hibmc_dp_hw_init().

And also need to move the HDCP cfg after DP controller de-resets, so
that HDCP configuration takes effect.

Fixes: 3c7623fb5bb6 ("drm/hisilicon/hibmc: Enable this hot plug detect of irq feature")
Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
ChangeLog:
v4 -> v5:
  - combined 9 and 11 patch together, suggested by Dmitry Baryshkov.
---
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
index 23df0d5228ca..2954e3066923 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
@@ -177,13 +177,16 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
 	dp_dev->link.cap.lanes = 0x2;
 	dp_dev->link.cap.link_rate = DP_LINK_BW_8_1;
 
-	/* hdcp data */
-	writel(HIBMC_DP_HDCP, dp_dev->base + HIBMC_DP_HDCP_CFG);
 	/* int init */
 	writel(0, dp_dev->base + HIBMC_DP_INTR_ENABLE);
 	writel(HIBMC_DP_INT_RST, dp_dev->base + HIBMC_DP_INTR_ORIGINAL_STATUS);
 	/* rst */
+	writel(0, dp_dev->base + HIBMC_DP_DPTX_RST_CTRL);
+	usleep_range(30, 50);
+	/* de-rst */
 	writel(HIBMC_DP_DPTX_RST, dp_dev->base + HIBMC_DP_DPTX_RST_CTRL);
+	/* hdcp data */
+	writel(HIBMC_DP_HDCP, dp_dev->base + HIBMC_DP_HDCP_CFG);
 	/* clock enable */
 	writel(HIBMC_DP_CLK_EN, dp_dev->base + HIBMC_DP_DPTX_CLK_CTRL);
 
-- 
2.33.0

[PATCH v8 drm-dp 4/4] drm/hisilicon/hibmc: Adding reset colorbar cfg in dp init.

[Yongbang Shi]

From: Baihan Li <libaihan@huawei.com>

Add colorbar disable operation before reset chontroller, to make sure
colorbar status is clear in the DP init, so if rmmod the driver and the
previous colorbar configuration will not affect the next time insmod the
driver.

Fixes: 3c7623fb5bb6 ("drm/hisilicon/hibmc: Enable this hot plug detect of irq feature")
Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
index 2954e3066923..b458cb7628d5 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
@@ -180,6 +180,8 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
 	/* int init */
 	writel(0, dp_dev->base + HIBMC_DP_INTR_ENABLE);
 	writel(HIBMC_DP_INT_RST, dp_dev->base + HIBMC_DP_INTR_ORIGINAL_STATUS);
+	/* clr colorbar */
+	writel(0, dp_dev->base + HIBMC_DP_COLOR_BAR_CTRL);
 	/* rst */
 	writel(0, dp_dev->base + HIBMC_DP_DPTX_RST_CTRL);
 	usleep_range(30, 50);
-- 
2.33.0

Re: [PATCH v8 drm-dp 1/4] drm/hisilicon/hibmc: fix dp probabilistical detect errors after HPD irq

[Dmitry Baryshkov]

On Fri, Sep 26, 2025 at 09:14:57AM +0800, Yongbang Shi wrote:
> From: Baihan Li <libaihan@huawei.com>
> 
> The issue is that drm_connector_helper_detect_from_ddc() returns wrong
> status when plugging or unplugging the monitor. Use HPD pin status in
> DP's detect_ctx() for real physcal monitor in/out, and implementation
> a complete DP detection including read DPCD, check if it's a branch
> device and its sink count for different situations.
> 
> Fixes: 3c7623fb5bb6 ("drm/hisilicon/hibmc: Enable this hot plug detect of irq feature")
> Signed-off-by: Baihan Li <libaihan@huawei.com>
> Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
> ---
> ChangeLog:
> v7 -> v8:
>   - fix build errors reported by kernel test robot <lkp@intel.com>
>     Closes: https://lore.kernel.org/oe-kbuild-all/202509241625.o4mNleVb-lkp@intel.com/
> v6 -> v7:
>   - add the check about branch devices, suggested by Dmitry Baryshkov.
> v5 -> v6:
>   - use HPD status in DP detect_ctx(), suggested by Dmitry Baryshkov.
> v4 -> v5:
>   - fix the commit message and DP detect_ctx(), suggested by Dmitry Baryshkov.
> ---
>  drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h  |  4 ++
>  drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c    | 12 +++++
>  drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h    |  6 +++
>  drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h   |  3 ++
>  .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c    | 48 ++++++++++++++++++-
>  5 files changed, 71 insertions(+), 2 deletions(-)
> 

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>


-- 
With best wishes
Dmitry

Re: [PATCH v8 drm-dp 0/4] Fix hibmc driver bugs

[Yongbang Shi]

Gently ping, any further comments on these patches?
Are these good to be applied?

Thanks，
Baihan.


> From: Baihan Li <libaihan@huawei.com>
>
> There are some bugfix for hibmc-drm driver.
> ---
> ChangeLog:
> v7 -> v8:
>    - fix build errors reported by kernel test robot <lkp@intel.com>
>      Closes: https://lore.kernel.org/oe-kbuild-all/202509241625.o4mNleVb-lkp@intel.com/
> v6 -> v7:
>    - add the check about branch devices, suggested by Dmitry Baryshkov.
> v5 -> v6:
>    - use HPD status in DP detect_ctx(), suggested by Dmitry Baryshkov.
> v4 -> v5:
>    - Because some of patches are applied, this series only contains the rest of them.
>    - fix the commit and DP detect_ctx(), suggested by Dmitry Baryshkov.
>    - fix bugfix commit ID, suggested by Dmitry Baryshkov.
>    - remove the 08/11 patch, I'll add in next series.
>    - combined 9 and 11 patch together, suggested by Dmitry Baryshkov.
> v3 -> v4:
>    - remove link training process in hibmc_dp_detect(), suggested by Dmitry Baryshkov.
>    - remove if (dev->registered), suggested by Dmitry Baryshkov.
>    - remove non-related changes, suggested by Dmitry Baryshkov.
>    - Remove the clock check, suggested by Dmitry Baryshkov.
>    - ( I'll add them in next series after redesigning this part)
>    - add KVM edid in commit message, suggested by Dmitry Baryshkov.
>    - fix magic values, suggested by Dmitry Baryshkov.
>    - fix the commit subjects, suggested by Dmitry Baryshkov.
> v2 -> v3:
>    - fix hibmc_connector_get_modes() and hibmc_vdac_detect() to realize BMC KVM, suggested by Dmitry Baryshkov.
>    - fix the issue commit ID, suggested by Dmitry Baryshkov.
>    - split into 2 commits, suggested by Dmitry Baryshkov.
>    - add more comments in commit log, suggested by Dmitry Baryshkov.
> ---
>
> Baihan Li (4):
>    drm/hisilicon/hibmc: fix dp probabilistical detect errors after HPD
>      irq
>    drm/hisilicon/hibmc: add dp mode valid check
>    drm/hisilicon/hibmc: fix no showing problem with loading hibmc
>      manually
>    drm/hisilicon/hibmc: Adding reset colorbar cfg in dp init.
>
>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h  |  4 ++
>   .../gpu/drm/hisilicon/hibmc/dp/dp_config.h    |  2 +
>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c    | 31 ++++++++-
>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h    |  8 +++
>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h   |  3 +
>   .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c    | 67 ++++++++++++++++++-
>   6 files changed, 111 insertions(+), 4 deletions(-)
>

Re: [PATCH v8 drm-dp 1/4] drm/hisilicon/hibmc: fix dp probabilistical detect errors after HPD irq

[Yongbang Shi]

Hi Dmitry,

I'm replying here to follow up on this patch.
It has been a while since your RB, so I just want to check if there are any problems here for my patch,
or anything I can do better before it can be picked up?

Thanks,
Baihan

> On Fri, Sep 26, 2025 at 09:14:57AM +0800, Yongbang Shi wrote:
>> From: Baihan Li <libaihan@huawei.com>
>>
>> The issue is that drm_connector_helper_detect_from_ddc() returns wrong
>> status when plugging or unplugging the monitor. Use HPD pin status in
>> DP's detect_ctx() for real physcal monitor in/out, and implementation
>> a complete DP detection including read DPCD, check if it's a branch
>> device and its sink count for different situations.
>>
>> Fixes: 3c7623fb5bb6 ("drm/hisilicon/hibmc: Enable this hot plug detect of irq feature")
>> Signed-off-by: Baihan Li <libaihan@huawei.com>
>> Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
>> ---
>> ChangeLog:
>> v7 -> v8:
>>    - fix build errors reported by kernel test robot <lkp@intel.com>
>>      Closes: https://lore.kernel.org/oe-kbuild-all/202509241625.o4mNleVb-lkp@intel.com/
>> v6 -> v7:
>>    - add the check about branch devices, suggested by Dmitry Baryshkov.
>> v5 -> v6:
>>    - use HPD status in DP detect_ctx(), suggested by Dmitry Baryshkov.
>> v4 -> v5:
>>    - fix the commit message and DP detect_ctx(), suggested by Dmitry Baryshkov.
>> ---
>>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h  |  4 ++
>>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c    | 12 +++++
>>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h    |  6 +++
>>   drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h   |  3 ++
>>   .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c    | 48 ++++++++++++++++++-
>>   5 files changed, 71 insertions(+), 2 deletions(-)
>>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
>
>