Re: [PATCH 2/2] drm/msm: push IRQ setup into individual drivers

[Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>]

On 5/6/2022 6:00 PM, Dmitry Baryshkov wrote:
> Afther the commit f026e431cf86 ("drm/msm: Convert to Linux IRQ
> interfaces") converted MSM DRM driver to handle IRQs on it's own (rather
> than using the DRM IRQ mid-layer), there is little point in keeping
> irq wrapper in the msm_drv.c which just call into individual drivers.
> Push respective code into the mdp4/mdp5/dpu drivers and drop
> irq_preinstall/irq_postinstall/irq msm_kms funcs.

Isnt this change causing a lot of code duplication across mdp5/dpu/mdp4?

Do you have any future plans with respect to this separation?

I am missing why this separation into respective mdp4/5/dpu is necessary 
because struct msm_kms remains a common struct in all of this so it 
remaining in msm_drv will avoid duplication.

> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.h  | 13 +---
>   .../gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c | 28 ++++++++-
>   drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c       |  6 +-
>   drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h       |  7 +++
>   drivers/gpu/drm/msm/disp/mdp4/mdp4_irq.c      | 30 ++++++++-
>   drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c      |  4 +-
>   drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h      |  4 +-
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_irq.c      | 30 ++++++++-
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c      |  4 +-
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.h      |  4 +-
>   drivers/gpu/drm/msm/msm_drv.c                 | 62 +++----------------
>   drivers/gpu/drm/msm/msm_kms.h                 |  4 +-
>   12 files changed, 105 insertions(+), 91 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.h
> index b5b6e7031fb9..c6938b1f1870 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.h
> @@ -8,13 +8,6 @@
>   #include "dpu_kms.h"
>   #include "dpu_hw_interrupts.h"
>   
> -/**
> - * dpu_core_irq_preinstall - perform pre-installation of core IRQ handler
> - * @kms:		MSM KMS handle
> - * @return:		none
> - */
> -void dpu_core_irq_preinstall(struct msm_kms *kms);
> -
>   /**
>    * dpu_core_irq_uninstall - uninstall core IRQ handler
>    * @kms:		MSM KMS handle
> @@ -23,11 +16,11 @@ void dpu_core_irq_preinstall(struct msm_kms *kms);
>   void dpu_core_irq_uninstall(struct msm_kms *kms);
>   
>   /**
> - * dpu_core_irq - core IRQ handler
> + * dpu_core_irq_install - install core IRQ handler
>    * @kms:		MSM KMS handle
> - * @return:		interrupt handling status
> + * @return:		non-zero in case of an error
>    */
> -irqreturn_t dpu_core_irq(struct msm_kms *kms);
> +int dpu_core_irq_install(struct msm_kms *kms);
>   
>   /**
>    * dpu_core_irq_read - IRQ helper function for reading IRQ status
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> index d6498e45dc2c..fa4f99034a08 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> @@ -164,8 +164,9 @@ static void dpu_core_irq_callback_handler(struct dpu_kms *dpu_kms, int irq_idx)
>   	dpu_kms->hw_intr->irq_tbl[irq_idx].cb(dpu_kms->hw_intr->irq_tbl[irq_idx].arg, irq_idx);
>   }
>   
> -irqreturn_t dpu_core_irq(struct msm_kms *kms)
> +static irqreturn_t dpu_irq(int irq, void *arg)
>   {
> +	struct msm_kms *kms = arg;
>   	struct dpu_kms *dpu_kms = to_dpu_kms(kms);
>   	struct dpu_hw_intr *intr = dpu_kms->hw_intr;
>   	int reg_idx;
> @@ -541,7 +542,7 @@ void dpu_debugfs_core_irq_init(struct dpu_kms *dpu_kms,
>   }
>   #endif
>   
> -void dpu_core_irq_preinstall(struct msm_kms *kms)
> +static void dpu_core_irq_preinstall(struct msm_kms *kms)
>   {
>   	struct dpu_kms *dpu_kms = to_dpu_kms(kms);
>   	int i;
> @@ -570,5 +571,28 @@ void dpu_core_irq_uninstall(struct msm_kms *kms)
>   
>   	dpu_clear_irqs(dpu_kms);
>   	dpu_disable_all_irqs(dpu_kms);
> +	if (kms->irq_requested)
> +		free_irq(kms->irq, kms);
>   	pm_runtime_put_sync(&dpu_kms->pdev->dev);
>   }
> +
> +int dpu_core_irq_install(struct msm_kms *kms)
> +{
> +	int ret;
> +
> +	dpu_core_irq_preinstall(kms);
> +
> +	ret = request_irq(kms->irq, dpu_irq, 0, "dpu", kms);
> +	if (ret)
> +		return ret;
> +
> +	kms->irq_requested = true;
> +
> +	ret = dpu_irq_postinstall(kms);
> +	if (ret) {
> +		free_irq(kms->irq, kms);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> index 2b9d931474e0..494978da7785 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> @@ -884,7 +884,7 @@ static void dpu_kms_destroy(struct msm_kms *kms)
>   		pm_runtime_disable(&dpu_kms->pdev->dev);
>   }
>   
> -static int dpu_irq_postinstall(struct msm_kms *kms)
> +int dpu_irq_postinstall(struct msm_kms *kms)
>   {
>   	struct msm_drm_private *priv;
>   	struct dpu_kms *dpu_kms = to_dpu_kms(kms);
> @@ -960,10 +960,8 @@ static void dpu_kms_mdp_snapshot(struct msm_disp_state *disp_state, struct msm_k
>   
>   static const struct msm_kms_funcs kms_funcs = {
>   	.hw_init         = dpu_kms_hw_init,
> -	.irq_preinstall  = dpu_core_irq_preinstall,
> -	.irq_postinstall = dpu_irq_postinstall,
> +	.irq_install     = dpu_core_irq_install,
>   	.irq_uninstall   = dpu_core_irq_uninstall,
> -	.irq             = dpu_core_irq,
>   	.enable_commit   = dpu_kms_enable_commit,
>   	.disable_commit  = dpu_kms_disable_commit,
>   	.vsync_time      = dpu_kms_vsync_time,
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> index 832a0769f2e7..559184c64045 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> @@ -204,4 +204,11 @@ void dpu_disable_vblank(struct msm_kms *kms, struct drm_crtc *crtc);
>    */
>   u64 dpu_kms_get_clk_rate(struct dpu_kms *dpu_kms, char *clock_name);
>   
> +/**
> + * dpu_irq_postinstall - perform post-installation of core IRQ handler
> + * @kms:               MSM KMS handle
> + * @return:            non-zero in case of error
> + */
> +int dpu_irq_postinstall(struct msm_kms *kms);
> +
>   #endif /* __dpu_kms_H__ */
> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_irq.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_irq.c
> index 4d49f3ba6a96..87675c162eea 100644
> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_irq.c
> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_irq.c
> @@ -32,7 +32,7 @@ static void mdp4_irq_error_handler(struct mdp_irq *irq, uint32_t irqstatus)
>   	}
>   }
>   
> -void mdp4_irq_preinstall(struct msm_kms *kms)
> +static void mdp4_irq_preinstall(struct msm_kms *kms)
>   {
>   	struct mdp4_kms *mdp4_kms = to_mdp4_kms(to_mdp_kms(kms));
>   	mdp4_enable(mdp4_kms);
> @@ -41,7 +41,7 @@ void mdp4_irq_preinstall(struct msm_kms *kms)
>   	mdp4_disable(mdp4_kms);
>   }
>   
> -int mdp4_irq_postinstall(struct msm_kms *kms)
> +static int mdp4_irq_postinstall(struct msm_kms *kms)
>   {
>   	struct mdp_kms *mdp_kms = to_mdp_kms(kms);
>   	struct mdp4_kms *mdp4_kms = to_mdp4_kms(mdp_kms);
> @@ -62,10 +62,13 @@ void mdp4_irq_uninstall(struct msm_kms *kms)
>   	mdp4_enable(mdp4_kms);
>   	mdp4_write(mdp4_kms, REG_MDP4_INTR_ENABLE, 0x00000000);
>   	mdp4_disable(mdp4_kms);
> +	if (kms->irq_requested)
> +		free_irq(kms->irq, kms);
>   }
>   
> -irqreturn_t mdp4_irq(struct msm_kms *kms)
> +static irqreturn_t mdp4_irq(int irq, void *arg)
>   {
> +	struct msm_kms *kms = arg;
>   	struct mdp_kms *mdp_kms = to_mdp_kms(kms);
>   	struct mdp4_kms *mdp4_kms = to_mdp4_kms(mdp_kms);
>   	struct drm_device *dev = mdp4_kms->dev;
> @@ -88,6 +91,27 @@ irqreturn_t mdp4_irq(struct msm_kms *kms)
>   	return IRQ_HANDLED;
>   }
>   
> +int mdp4_irq_install(struct msm_kms *kms)
> +{
> +	int ret;
> +
> +	mdp4_irq_preinstall(kms);
> +
> +	ret = request_irq(kms->irq, mdp4_irq, 0, "mdp4", kms);
> +	if (ret)
> +		return ret;
> +
> +	kms->irq_requested = true;
> +
> +	ret = mdp4_irq_postinstall(kms);
> +	if (ret) {
> +		free_irq(kms->irq, kms);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>   int mdp4_enable_vblank(struct msm_kms *kms, struct drm_crtc *crtc)
>   {
>   	struct mdp4_kms *mdp4_kms = to_mdp4_kms(to_mdp_kms(kms));
> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
> index fb48c8c19ec3..b7aced272af9 100644
> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
> @@ -148,10 +148,8 @@ static void mdp4_destroy(struct msm_kms *kms)
>   static const struct mdp_kms_funcs kms_funcs = {
>   	.base = {
>   		.hw_init         = mdp4_hw_init,
> -		.irq_preinstall  = mdp4_irq_preinstall,
> -		.irq_postinstall = mdp4_irq_postinstall,
> +		.irq_install     = mdp4_irq_install,
>   		.irq_uninstall   = mdp4_irq_uninstall,
> -		.irq             = mdp4_irq,
>   		.enable_vblank   = mdp4_enable_vblank,
>   		.disable_vblank  = mdp4_disable_vblank,
>   		.enable_commit   = mdp4_enable_commit,
> diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h
> index e8ee92ab7956..b24a63872232 100644
> --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h
> +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h
> @@ -157,10 +157,8 @@ int mdp4_enable(struct mdp4_kms *mdp4_kms);
>   
>   void mdp4_set_irqmask(struct mdp_kms *mdp_kms, uint32_t irqmask,
>   		uint32_t old_irqmask);
> -void mdp4_irq_preinstall(struct msm_kms *kms);
> -int mdp4_irq_postinstall(struct msm_kms *kms);
> +int mdp4_irq_install(struct msm_kms *kms);
>   void mdp4_irq_uninstall(struct msm_kms *kms);
> -irqreturn_t mdp4_irq(struct msm_kms *kms);
>   int mdp4_enable_vblank(struct msm_kms *kms, struct drm_crtc *crtc);
>   void mdp4_disable_vblank(struct msm_kms *kms, struct drm_crtc *crtc);
>   
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_irq.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_irq.c
> index 9b4c8d92ff32..d573ff29d5a4 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_irq.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_irq.c
> @@ -36,7 +36,7 @@ static void mdp5_irq_error_handler(struct mdp_irq *irq, uint32_t irqstatus)
>   	}
>   }
>   
> -void mdp5_irq_preinstall(struct msm_kms *kms)
> +static void mdp5_irq_preinstall(struct msm_kms *kms)
>   {
>   	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
>   	struct device *dev = &mdp5_kms->pdev->dev;
> @@ -47,7 +47,7 @@ void mdp5_irq_preinstall(struct msm_kms *kms)
>   	pm_runtime_put_sync(dev);
>   }
>   
> -int mdp5_irq_postinstall(struct msm_kms *kms)
> +static int mdp5_irq_postinstall(struct msm_kms *kms)
>   {
>   	struct mdp_kms *mdp_kms = to_mdp_kms(kms);
>   	struct mdp5_kms *mdp5_kms = to_mdp5_kms(mdp_kms);
> @@ -74,11 +74,14 @@ void mdp5_irq_uninstall(struct msm_kms *kms)
>   
>   	pm_runtime_get_sync(dev);
>   	mdp5_write(mdp5_kms, REG_MDP5_INTR_EN, 0x00000000);
> +	if (kms->irq_requested)
> +		free_irq(kms->irq, kms);
>   	pm_runtime_put_sync(dev);
>   }
>   
> -irqreturn_t mdp5_irq(struct msm_kms *kms)
> +static irqreturn_t mdp5_irq(int irq, void *arg)
>   {
> +	struct msm_kms *kms = arg;
>   	struct mdp_kms *mdp_kms = to_mdp_kms(kms);
>   	struct mdp5_kms *mdp5_kms = to_mdp5_kms(mdp_kms);
>   	struct drm_device *dev = mdp5_kms->dev;
> @@ -101,6 +104,27 @@ irqreturn_t mdp5_irq(struct msm_kms *kms)
>   	return IRQ_HANDLED;
>   }
>   
> +int mdp5_irq_install(struct msm_kms *kms)
> +{
> +	int ret;
> +
> +	mdp5_irq_preinstall(kms);
> +
> +	ret = request_irq(kms->irq, mdp5_irq, 0, "mdp5", kms);
> +	if (ret)
> +		return ret;
> +
> +	kms->irq_requested = true;
> +
> +	ret = mdp5_irq_postinstall(kms);
> +	if (ret) {
> +		free_irq(kms->irq, kms);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>   int mdp5_enable_vblank(struct msm_kms *kms, struct drm_crtc *crtc)
>   {
>   	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> index 3d5621a68f85..18cf0ff4da6c 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> @@ -262,10 +262,8 @@ static int mdp5_kms_debugfs_init(struct msm_kms *kms, struct drm_minor *minor)
>   static const struct mdp_kms_funcs kms_funcs = {
>   	.base = {
>   		.hw_init         = mdp5_hw_init,
> -		.irq_preinstall  = mdp5_irq_preinstall,
> -		.irq_postinstall = mdp5_irq_postinstall,
> +		.irq_install     = mdp5_irq_install,
>   		.irq_uninstall   = mdp5_irq_uninstall,
> -		.irq             = mdp5_irq,
>   		.enable_vblank   = mdp5_enable_vblank,
>   		.disable_vblank  = mdp5_disable_vblank,
>   		.flush_commit    = mdp5_flush_commit,
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.h b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.h
> index 29bf11f08601..630b5f812f24 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.h
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.h
> @@ -263,10 +263,8 @@ static inline uint32_t lm2ppdone(struct mdp5_hw_mixer *mixer)
>   
>   void mdp5_set_irqmask(struct mdp_kms *mdp_kms, uint32_t irqmask,
>   		uint32_t old_irqmask);
> -void mdp5_irq_preinstall(struct msm_kms *kms);
> -int mdp5_irq_postinstall(struct msm_kms *kms);
> +int mdp5_irq_install(struct msm_kms *kms);
>   void mdp5_irq_uninstall(struct msm_kms *kms);
> -irqreturn_t mdp5_irq(struct msm_kms *kms);
>   int mdp5_enable_vblank(struct msm_kms *kms, struct drm_crtc *crtc);
>   void mdp5_disable_vblank(struct msm_kms *kms, struct drm_crtc *crtc);
>   int mdp5_irq_domain_init(struct mdp5_kms *mdp5_kms);
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 44485363f37a..d2fbe54fec4d 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -77,64 +77,15 @@ static bool modeset = true;
>   MODULE_PARM_DESC(modeset, "Use kernel modesetting [KMS] (1=on (default), 0=disable)");
>   module_param(modeset, bool, 0600);
>   
> -static irqreturn_t msm_irq(int irq, void *arg)
> -{
> -	struct drm_device *dev = arg;
> -	struct msm_drm_private *priv = dev->dev_private;
> -	struct msm_kms *kms = priv->kms;
> -
> -	BUG_ON(!kms);
> -
> -	return kms->funcs->irq(kms);
> -}
> -
> -static void msm_irq_preinstall(struct drm_device *dev)
> -{
> -	struct msm_drm_private *priv = dev->dev_private;
> -	struct msm_kms *kms = priv->kms;
> -
> -	BUG_ON(!kms);
> -
> -	kms->funcs->irq_preinstall(kms);
> -}
> -
> -static int msm_irq_postinstall(struct drm_device *dev)
> -{
> -	struct msm_drm_private *priv = dev->dev_private;
> -	struct msm_kms *kms = priv->kms;
> -
> -	BUG_ON(!kms);
> -
> -	if (kms->funcs->irq_postinstall)
> -		return kms->funcs->irq_postinstall(kms);
> -
> -	return 0;
> -}
> -
>   static int msm_irq_install(struct drm_device *dev, unsigned int irq)
>   {
>   	struct msm_drm_private *priv = dev->dev_private;
>   	struct msm_kms *kms = priv->kms;
> -	int ret;
> -
> -	if (irq == IRQ_NOTCONNECTED)
> -		return -ENOTCONN;
> -
> -	msm_irq_preinstall(dev);
> -
> -	ret = request_irq(irq, msm_irq, 0, dev->driver->name, dev);
> -	if (ret)
> -		return ret;
> -
> -	kms->irq_requested = true;
>   
> -	ret = msm_irq_postinstall(dev);
> -	if (ret) {
> -		free_irq(irq, dev);
> -		return ret;
> -	}
> +	if (!kms->funcs->irq_install)
> +		return -EINVAL;
>   
> -	return 0;
> +	return kms->funcs->irq_install(kms);
>   }
>   
>   static void msm_irq_uninstall(struct drm_device *dev)
> @@ -143,8 +94,6 @@ static void msm_irq_uninstall(struct drm_device *dev)
>   	struct msm_kms *kms = priv->kms;
>   
>   	kms->funcs->irq_uninstall(kms);
> -	if (kms->irq_requested)
> -		free_irq(kms->irq, dev);
>   }
>   
>   struct msm_vblank_work {
> @@ -450,6 +399,11 @@ static int msm_drm_init(struct device *dev, const struct drm_driver *drv)
>   	}
>   
>   	if (kms) {
> +		if (kms->irq == IRQ_NOTCONNECTED) {
> +			ret = -ENOTCONN;
> +			goto err_msm_uninit;
> +		}
> +
>   		pm_runtime_get_sync(dev);
>   		ret = msm_irq_install(ddev, kms->irq);
>   		pm_runtime_put_sync(dev);
> diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
> index f8ed7588928c..71d497a8fb8b 100644
> --- a/drivers/gpu/drm/msm/msm_kms.h
> +++ b/drivers/gpu/drm/msm/msm_kms.h
> @@ -24,10 +24,8 @@ struct msm_kms_funcs {
>   	/* hw initialization: */
>   	int (*hw_init)(struct msm_kms *kms);
>   	/* irq handling: */
> -	void (*irq_preinstall)(struct msm_kms *kms);
> -	int (*irq_postinstall)(struct msm_kms *kms);
> +	int (*irq_install)(struct msm_kms *kms);
>   	void (*irq_uninstall)(struct msm_kms *kms);
> -	irqreturn_t (*irq)(struct msm_kms *kms);
>   	int (*enable_vblank)(struct msm_kms *kms, struct drm_crtc *crtc);
>   	void (*disable_vblank)(struct msm_kms *kms, struct drm_crtc *crtc);
>