[PATCH v2 drm-dp 7/7] drm/hisilicon/hibmc: Enable this hot plug detect of irq feature
Dmitry Baryshkov
dmitry.baryshkov at linaro.org
Thu Feb 13 00:50:57 UTC 2025
On Mon, Feb 10, 2025 at 10:49:59PM +0800, Yongbang Shi wrote:
> From: Baihan Li <libaihan at huawei.com>
>
> To realize HPD feature, we have getting hpd status function, registering
> irq function, interrupt handler function, and hpd event process function.
> And also we use pci_alloc_irq_vectors() to get our msi irq, because we have
> two interrupts now.
>
> Signed-off-by: Baihan Li <libaihan at huawei.com>
> Signed-off-by: Yongbang Shi <shiyongbang at huawei.com>
> ---
> ChangeLog:
> v1 -> v2:
> - optimizing the description in commit message, suggested by Dmitry Baryshkov.
> - add mdelay(100) comments, suggested by Dmitry Baryshkov.
> - deleting display enable in hpd event, suggested by Dmitry Baryshkov.
> ---
> .../gpu/drm/hisilicon/hibmc/dp/dp_config.h | 1 +
> drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c | 33 ++++++++
> drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h | 13 ++++
> drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h | 2 +
> .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c | 57 +++++++++++++-
> .../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 78 +++++++++++++++----
> .../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h | 14 ++++
> 7 files changed, 181 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
> index c5feef8dc27d..08f9e1caf7fc 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
> @@ -16,5 +16,6 @@
> #define HIBMC_DP_SYNC_EN_MASK 0x3
> #define HIBMC_DP_LINK_RATE_CAL 27
> #define HIBMC_DP_SYNC_DELAY(lanes) ((lanes) == 0x2 ? 86 : 46)
> +#define HIBMC_DP_INT_ENABLE 0xc
>
> #endif
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> index 5e889c377117..0b6ce48c5d8f 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> @@ -181,6 +181,7 @@ 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);
> + writel(HIBMC_DP_INT_ENABLE, dp_dev->base + HIBMC_DP_INTR_ENABLE);
> /* rst */
> writel(HIBMC_DP_DPTX_RST, dp_dev->base + HIBMC_DP_DPTX_RST_CTRL);
> /* clock enable */
> @@ -284,3 +285,35 @@ 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);
> }
> +
> +enum hibmc_dp_hpd_status hibmc_dp_get_hpd_status(const struct hibmc_dp *dp)
> +{
> + enum hibmc_dp_hpd_status status;
> + u32 val;
> +
> + /* spec said the HPD signal needs to be pulled up for
> + * more than 100 ms to enter the plug status
> + */
> + mdelay(100);
Please check that your code doesn't break with CONFIG_DEBUG_ATOMIC_SLEEP=y
Having a 100msec delay in the ISR handler is a really sad idea. Don't
you have HPD debouncing handled in the hardware?
> +
> + val = readl(dp->dp_dev->base + HIBMC_DP_HPD_STATUS);
> + val = (val & HIBMC_DP_CFG_SINK_HPD_STATE_MACHINE) >> 4;
> +
> + switch (val) {
> + case 0: /* 0: IDLE */
> + case 3: /* 3: DONE */
> + status = HIBMC_DP_HPD_OUT;
> + break;
> + case 1: /* 1: PLUG */
> + status = HIBMC_DP_HPD_IN;
> + break;
> + case 4: /* 4: ASSERT_LENGHT */
> + status = HIBMC_DP_HPD_DETECTING;
> + break;
> + default: /* unknown status */
> + status = HIBMC_DP_HPD_DET_FAIL;
> + break;
> + }
Is there a way to detect a short pulse on the HPD line aka attention?
You have defined HIBMC_DP_HPD_SHORT below, but it is not being assigned
at all.
> +
> + return status;
> +}
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> index 823544b8008b..df7b692b1998 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> @@ -41,6 +41,17 @@ struct hibmc_dp_cbar_cfg {
> enum hibmc_dp_cbar_pattern pattern;
> };
>
> +enum hibmc_dp_hpd_status {
> + HIBMC_DP_HPD_DETECTING,
> + HIBMC_DP_HPD_IN,
> + HIBMC_DP_HPD_OUT,
> + HIBMC_DP_HPD_SHORT, /* Short hpd (irq_hpd) */
> + HIBMC_DP_HPD_DET_FAIL,
> + HIBMC_DP_HPD_IN_SIMULATE,
> + HIBMC_DP_HPD_OUT_SIMULATE,
> + HIBMC_DP_HPD_SHORT_SIMULATE,
> +};
> +
> struct hibmc_dp {
> struct hibmc_dp_dev *dp_dev;
> struct drm_device *drm_dev;
> @@ -49,6 +60,7 @@ struct hibmc_dp {
> void __iomem *mmio;
> struct drm_dp_aux aux;
> struct hibmc_dp_cbar_cfg cfg;
> + u32 hpd_status;
> };
>
> int hibmc_dp_hw_init(struct hibmc_dp *dp);
> @@ -58,5 +70,6 @@ int hibmc_dp_get_dpcd(struct hibmc_dp *dp);
> u8 hibmc_dp_get_link_rate(struct hibmc_dp *dp);
> u8 hibmc_dp_get_lanes(struct hibmc_dp *dp);
> void hibmc_dp_set_cbar(struct hibmc_dp *dp, const struct hibmc_dp_cbar_cfg *cfg);
> +enum hibmc_dp_hpd_status hibmc_dp_get_hpd_status(const 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 c43ad6b30c2c..6c4ba0412b15 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
> @@ -12,6 +12,7 @@
> #define HIBMC_DP_AUX_RD_DATA0 0x64
> #define HIBMC_DP_AUX_REQ 0x74
> #define HIBMC_DP_AUX_STATUS 0x78
> +#define HIBMC_DP_HPD_STATUS 0x98
> #define HIBMC_DP_PHYIF_CTRL0 0xa0
> #define HIBMC_DP_VIDEO_CTRL 0x100
> #define HIBMC_DP_VIDEO_CONFIG0 0x104
> @@ -75,5 +76,6 @@
> #define HIBMC_DP_CFG_STREAM_HTOTAL_SIZE GENMASK(31, 16)
> #define HIBMC_DP_CFG_STREAM_HBLANK_SIZE GENMASK(15, 0)
> #define HIBMC_DP_CFG_STREAM_SYNC_CALIBRATION GENMASK(31, 20)
> +#define HIBMC_DP_CFG_SINK_HPD_STATE_MACHINE GENMASK(7, 4)
>
> #endif
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> index 1f8f7b74f5b4..057dd3caa043 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> @@ -11,8 +11,12 @@
> #include <drm/drm_edid.h>
>
> #include "hibmc_drm_drv.h"
> +#include "hibmc_drm_regs.h"
> #include "dp/dp_hw.h"
>
> +#define DP_MASKED_SINK_HPD_UNPLUG_INT BIT(3)
> +#define DP_MASKED_SINK_HPD_PLUG_INT BIT(2)
> +
> static const struct drm_connector_helper_funcs hibmc_dp_conn_helper_funcs = {
> .get_modes = drm_connector_helper_get_modes,
> .detect_ctx = drm_connector_helper_detect_from_ddc,
> @@ -81,6 +85,53 @@ static const struct drm_encoder_helper_funcs hibmc_dp_encoder_helper_funcs = {
> .atomic_disable = hibmc_dp_encoder_disable,
> };
>
> +static int hibmc_dp_cfg(struct hibmc_dp *dp)
> +{
> + int ret;
> +
> + ret = hibmc_dp_hw_init(dp);
> + if (ret)
> + return ret;
> +
> + hibmc_dp_display_en(dp, false);
Does this enable video signal? You should only enable AUX and perform
link training at this point.
> +
> + return 0;
> +}
> +
> +irqreturn_t hibmc_dp_hpd_event_isr(int irq, void *arg)
> +{
> + struct drm_device *dev = (struct drm_device *)arg;
> + struct hibmc_drm_private *priv = to_hibmc_drm_private(dev);
> + enum hibmc_dp_hpd_status status;
> + int idx;
> +
> + if (!drm_dev_enter(dev, &idx))
> + return -ENODEV;
> +
> + status = hibmc_dp_get_hpd_status(&priv->dp);
> + if (status == HIBMC_DP_HPD_IN) {
> + if (!(priv->dp.hpd_status & DP_MASKED_SINK_HPD_PLUG_INT))
> + goto err;
> + drm_dbg_dp(&priv->dev, "HPD IN isr occur!\n");
> + hibmc_dp_cfg(&priv->dp);
> + drm_kms_helper_connector_hotplug_event(&priv->dp.connector);
> + } else if (status == HIBMC_DP_HPD_OUT) {
> + if (!(priv->dp.hpd_status & DP_MASKED_SINK_HPD_UNPLUG_INT))
> + goto err;
> + drm_dbg_dp(&priv->dev, "HPD OUT isr occur!\n");
> + drm_kms_helper_connector_hotplug_event(&priv->dp.connector);
This looks like a hand-coded drm_connector_helper_hpd_irq_event()
> + } else {
> + drm_warn(&priv->dev, "HPD unknown isr occur, status: %d\n", status);
> + }
> +
> +err:
> + priv->dp.hpd_status = 0;
> +
> + drm_dev_exit(idx);
> +
> + return IRQ_HANDLED;
> +}
> +
> int hibmc_dp_init(struct hibmc_drm_private *priv)
> {
> struct drm_device *dev = &priv->dev;
> @@ -93,14 +144,12 @@ int hibmc_dp_init(struct hibmc_drm_private *priv)
> dp->mmio = priv->mmio;
> dp->drm_dev = dev;
>
> - ret = hibmc_dp_hw_init(&priv->dp);
> + ret = hibmc_dp_cfg(dp);
> if (ret) {
> - drm_err(dev, "hibmc dp hw init failed: %d\n", ret);
> + drm_err(dev, "hibmc dp cfg failed: %d\n", ret);
> return ret;
> }
>
> - hibmc_dp_display_en(&priv->dp, false);
> -
> encoder->possible_crtcs = drm_crtc_mask(crtc);
> ret = drmm_encoder_init(dev, encoder, NULL, DRM_MODE_ENCODER_TMDS, NULL);
> if (ret) {
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> index bade693d9730..199acb3e7a73 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> @@ -29,9 +29,13 @@
> #include "hibmc_drm_regs.h"
>
> #define HIBMC_DP_HOST_SERDES_CTRL 0x1f001c
> +#define HIBMC_DP_INTSTAT 0x1e0724
> +#define HIBMC_DP_INTCLR 0x1e0728
Why are those defined outside of hibmc_drm_regs.h?
>
> DEFINE_DRM_GEM_FOPS(hibmc_fops);
>
> +static const char *g_irqs_names_map[HIBMC_MAX_VECTORS] = { "vblank", "hpd" };
> +
> static irqreturn_t hibmc_interrupt(int irq, void *arg)
> {
> struct drm_device *dev = (struct drm_device *)arg;
> @@ -49,6 +53,22 @@ static irqreturn_t hibmc_interrupt(int irq, void *arg)
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t hibmc_dp_interrupt(int irq, void *arg)
> +{
> + struct drm_device *dev = (struct drm_device *)arg;
> + struct hibmc_drm_private *priv = to_hibmc_drm_private(dev);
> + u32 status;
> +
> + status = readl(priv->mmio + HIBMC_DP_INTSTAT);
> + if (status) {
> + priv->dp.hpd_status = status;
> + writel(status, priv->mmio + HIBMC_DP_INTCLR);
> + return IRQ_WAKE_THREAD;
> + }
> +
> + return IRQ_HANDLED;
> +}
> +
> static int hibmc_dumb_create(struct drm_file *file, struct drm_device *dev,
> struct drm_mode_create_dumb *args)
> {
> @@ -248,15 +268,52 @@ static int hibmc_hw_init(struct hibmc_drm_private *priv)
> return 0;
> }
>
> -static int hibmc_unload(struct drm_device *dev)
> +static void hibmc_unload(struct drm_device *dev)
> +{
> + drm_atomic_helper_shutdown(dev);
> +
> + pci_disable_msi(to_pci_dev(dev->dev));
> +}
> +
> +static int hibmc_msi_init(struct drm_device *dev)
> {
> + struct hibmc_drm_private *priv = to_hibmc_drm_private(dev);
> struct pci_dev *pdev = to_pci_dev(dev->dev);
> + int ret;
>
> - drm_atomic_helper_shutdown(dev);
> + ret = pci_alloc_irq_vectors(pdev, HIBMC_MIN_VECTORS,
> + HIBMC_MAX_VECTORS, PCI_IRQ_MSI);
> + if (ret < 0) {
> + drm_err(dev, "enabling MSI failed: %d\n", ret);
> + return ret;
> + }
>
> - free_irq(pdev->irq, dev);
> + priv->valid_irq_num = ret;
>
> - pci_disable_msi(to_pci_dev(dev->dev));
> + priv->irqs = drmm_kcalloc(dev, priv->valid_irq_num,
> + sizeof(struct hibmc_irq), GFP_KERNEL);
Why do you need an extra pointer? You know that there are no more than
HIBMC_MAX_VECTORS, so you can have this data as a part of your private
structure.
> + if (!priv->irqs)
> + return -ENOMEM;
> +
> + for (int i = 0; i < priv->valid_irq_num; i++) {
> + snprintf(priv->irqs[i].name, sizeof(priv->irqs[i].name) - 1, "%s-%s-%s",
> + dev->driver->name, pci_name(pdev), g_irqs_names_map[i]);
> +
> + priv->irqs[i].irq_num = pci_irq_vector(pdev, i);
> +
> + if (i)
> + /* PCI devices require shared interrupts. */
> + ret = devm_request_threaded_irq(&pdev->dev, priv->irqs[i].irq_num,
> + hibmc_dp_interrupt, hibmc_dp_hpd_event_isr,
> + IRQF_SHARED, priv->irqs[i].name, dev);
> + else
> + ret = devm_request_irq(&pdev->dev, priv->irqs[i].irq_num, hibmc_interrupt,
> + IRQF_SHARED, priv->irqs[i].name, dev);
This feels like "too many changes". You have MSI-related changes, devm_,
your HPD interrupt. Please split this patch into logical parts.
> + if (ret) {
> + drm_err(dev, "install irq failed: %d\n", ret);
> + return ret;
> + }
> + }
>
> return 0;
> }
> @@ -288,15 +345,10 @@ static int hibmc_load(struct drm_device *dev)
> goto err;
> }
>
> - ret = pci_enable_msi(pdev);
> + ret = hibmc_msi_init(dev);
> if (ret) {
> - drm_warn(dev, "enabling MSI failed: %d\n", ret);
> - } else {
> - /* PCI devices require shared interrupts. */
> - ret = request_irq(pdev->irq, hibmc_interrupt, IRQF_SHARED,
> - dev->driver->name, dev);
> - if (ret)
> - drm_warn(dev, "install irq failed: %d\n", ret);
> + drm_err(dev, "hibmc msi init failed, ret:%d\n", ret);
> + goto err;
> }
>
> /* reset all the states of crtc/plane/encoder/connector */
> @@ -372,7 +424,7 @@ static void hibmc_pci_remove(struct pci_dev *pdev)
>
> static void hibmc_pci_shutdown(struct pci_dev *pdev)
> {
> - drm_atomic_helper_shutdown(pci_get_drvdata(pdev));
> + hibmc_pci_remove(pdev);
> }
>
> static const struct pci_device_id hibmc_pci_table[] = {
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> index bc89e4b9f4e3..764e211a8779 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> @@ -22,6 +22,14 @@
>
> #include "dp/dp_hw.h"
>
> +#define HIBMC_MIN_VECTORS 1
> +#define HIBMC_MAX_VECTORS 2
> +
> +struct hibmc_irq {
> + s32 irq_num;
> + char name[32];
> +};
> +
> struct hibmc_vdac {
> struct drm_device *dev;
> struct drm_encoder encoder;
> @@ -40,6 +48,10 @@ struct hibmc_drm_private {
> struct drm_crtc crtc;
> struct hibmc_vdac vdac;
> struct hibmc_dp dp;
> +
> + /* irqs */
> + struct hibmc_irq *irqs;
> + u32 valid_irq_num;
> };
>
> static inline struct hibmc_vdac *to_hibmc_vdac(struct drm_connector *connector)
> @@ -71,4 +83,6 @@ int hibmc_dp_init(struct hibmc_drm_private *priv);
>
> void hibmc_debugfs_init(struct drm_connector *connector, struct dentry *root);
>
> +irqreturn_t hibmc_dp_hpd_event_isr(int irq, void *arg);
> +
> #endif
> --
> 2.33.0
>
--
With best wishes
Dmitry
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