Re: [Freedreno] [PATCH v2 4/7] drm/msm/dpu: allow just single IRQ callback

[Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>]

On 19/01/2022 03:10, abhinavk@xxxxxxxxxxxxxx wrote:
> <replying from my older email as i couldnt find this thread on my new one>
>
> On 2021-08-17 20:30, abhinavk@xxxxxxxxxxxxxx wrote:
> > On 2021-06-17 15:20, Dmitry Baryshkov wrote:
> > > DPU interrupts code allows multiple callbacks per interrut. In reality
> > /interrupt
> > > none of the interrupts is shared between blocks (and will probably never
> > > be). Drop support for registering multiple callbacks per interrupt to
> > > simplify interrupt handling code.
> > >
> > > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> >
> > I need to check on why we had this design originally and we still do.
> > the idx with which we are registering today can generate only one hw 
> > interrupt.
> > But i am not sure if something for planned for future use. Will update
> > in a day or two.
> >
> > meanwhile some comments and questions below.
>
> I did check internally on the original design of this and yes the plan 
> was for other
> sub-modules to register for callbacks and that callback goes into the 
> callback list.
>
> For example, lets say for some reason some other modules like the DSI 
> want to register
> for the VSYNC interrupt, it can register for a callback and that will 
> get added to the
> callback list.
>
> But, this never got used that way and even now there is only one 
> callback per interrupt.
> We dont have a concrete use-case where we will need this in the future 
> but like many other things,
> we cannot tell for certain.
>
> Since there is no concrete use-case where we might need this, if you 
> would like to go ahead
> with this, please do.
>
> Once you address the other comments on this, I can ack this.

Thanks for the info. I'll respin this on top of current msm-next + 
https://patchwork.freedesktop.org/patch/464350/

> > > ---
> > >  drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.h  |  18 +--
> > >  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c   |   6 +-
> > >  .../gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h  |   2 +-
> > >  .../drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c  |  10 +-
> > >  .../drm/msm/disp/dpu1/dpu_encoder_phys_vid.c  |   6 +-
> > >  .../gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c | 144 +++++++-----------
> > >  .../gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h |  12 +-
> > >  drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h       |  12 --
> > >  drivers/gpu/drm/msm/disp/dpu1/dpu_trace.h     |  10 +-
> > >  9 files changed, 86 insertions(+), 134 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 90ae6c9ccc95..44ab97fb2964 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.h
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.h
> > > @@ -46,10 +46,8 @@ u32 dpu_core_irq_read(
> > >   *                             interrupt
> > >   * @dpu_kms:        DPU handle
> > >   * @irq_idx:        irq index
> > > - * @irq_cb:        IRQ callback structure, containing callback function
> > > - *            and argument. Passing NULL for irq_cb will unregister
> > > - *            the callback for the given irq_idx
> > > - *            This must exist until un-registration.
> > > + * @irq_cb:        IRQ callback funcion.
> > > + * @irq_arg:        IRQ callback argument.
> > >   * @return:        0 for success registering callback, otherwise 
> > > failure
> > >   *
> > >   * This function supports registration of multiple callbacks for each
> > > interrupt.
> > > @@ -57,17 +55,16 @@ u32 dpu_core_irq_read(
> > >  int dpu_core_irq_register_callback(
> > >          struct dpu_kms *dpu_kms,
> > >          int irq_idx,
> > > -        struct dpu_irq_callback *irq_cb);
> > > +        void (*irq_cb)(void *arg, int irq_idx),
> > > +        void *irq_arg);
> > >
> > >  /**
> > >   * dpu_core_irq_unregister_callback - For unregistering callback
> > > function on IRQ
> > >   *                             interrupt
> > >   * @dpu_kms:        DPU handle
> > >   * @irq_idx:        irq index
> > > - * @irq_cb:        IRQ callback structure, containing callback function
> > > - *            and argument. Passing NULL for irq_cb will unregister
> > > - *            the callback for the given irq_idx
> > > - *            This must match with registration.
> > > + * @irq_cb:        IRQ callback funcion.
> > /function
> > this typo is there in multiple places
> > > + * @irq_arg:        IRQ callback argument.
> > >   * @return:        0 for success registering callback, otherwise 
> > > failure
> > >   *
> > >   * This function supports registration of multiple callbacks for each
> > > interrupt.
> > > @@ -75,7 +72,8 @@ int dpu_core_irq_register_callback(
> > >  int dpu_core_irq_unregister_callback(
> > >          struct dpu_kms *dpu_kms,
> > >          int irq_idx,
> > > -        struct dpu_irq_callback *irq_cb);
> > > +        void (*irq_cb)(void *arg, int irq_idx),
> > > +        void *irq_arg);
> > >
> > >  /**
> > >   * dpu_debugfs_core_irq_init - register core irq debugfs
> > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > > b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > > index 1c04b7cce43e..d3557b0f4db9 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> > > @@ -310,7 +310,7 @@ int dpu_encoder_helper_wait_for_irq(struct
> > > dpu_encoder_phys *phys_enc,
> > >                        phys_enc->hw_pp->idx - PINGPONG_0,
> > >                        atomic_read(wait_info->atomic_cnt));
> > >              local_irq_save(flags);
> > > -            irq->cb.func(phys_enc, irq->irq_idx);
> > > +            irq->func(phys_enc, irq->irq_idx);
> > >              local_irq_restore(flags);
> > >              ret = 0;
> > >          } else {
> > > @@ -352,7 +352,7 @@ int dpu_encoder_helper_register_irq(struct
> > > dpu_encoder_phys *phys_enc,
> > >      }
> > >
> > >      ret = dpu_core_irq_register_callback(phys_enc->dpu_kms, 
> > > irq->irq_idx,
> > > -            &irq->cb);
> > > +            irq->func, phys_enc);
> > >      if (ret) {
> > >          DPU_ERROR_PHYS(phys_enc,
> > >              "failed to register IRQ callback for %s\n",
> > > @@ -384,7 +384,7 @@ int dpu_encoder_helper_unregister_irq(struct
> > > dpu_encoder_phys *phys_enc,
> > >      }
> > >
> > >      ret = dpu_core_irq_unregister_callback(phys_enc->dpu_kms, 
> > > irq->irq_idx,
> > > -            &irq->cb);
> > > +            irq->func, phys_enc);
> > >      if (ret) {
> > >          DRM_ERROR("unreg cb fail id=%u, intr=%d, irq=%d ret=%d",
> > >                DRMID(phys_enc->parent), intr_idx,
> > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
> > > b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
> > > index e7270eb6b84b..80d87871fd94 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys.h
> > > @@ -174,7 +174,7 @@ struct dpu_encoder_irq {
> > >      const char *name;
> > >      enum dpu_intr_idx intr_idx;
> > >      int irq_idx;
> > > -    struct dpu_irq_callback cb;
> > > +    void (*func)(void *arg, int irq_idx);
> > >  };
> > >
> > >  /**
> > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > > b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > > index aa01698d6b25..f921a5c99456 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> > > @@ -782,30 +782,28 @@ struct dpu_encoder_phys 
> > > *dpu_encoder_phys_cmd_init(
> > >      phys_enc->enable_state = DPU_ENC_DISABLED;
> > >      for (i = 0; i < INTR_IDX_MAX; i++) {
> > >          irq = &phys_enc->irq[i];
> > > -        INIT_LIST_HEAD(&irq->cb.list);
> > >          irq->irq_idx = -EINVAL;
> > > -        irq->cb.arg = phys_enc;
> > >      }
> > >
> > >      irq = &phys_enc->irq[INTR_IDX_CTL_START];
> > >      irq->name = "ctl_start";
> > >      irq->intr_idx = INTR_IDX_CTL_START;
> > > -    irq->cb.func = dpu_encoder_phys_cmd_ctl_start_irq;
> > > +    irq->func = dpu_encoder_phys_cmd_ctl_start_irq;
> > >
> > >      irq = &phys_enc->irq[INTR_IDX_PINGPONG];
> > >      irq->name = "pp_done";
> > >      irq->intr_idx = INTR_IDX_PINGPONG;
> > > -    irq->cb.func = dpu_encoder_phys_cmd_pp_tx_done_irq;
> > > +    irq->func = dpu_encoder_phys_cmd_pp_tx_done_irq;
> > >
> > >      irq = &phys_enc->irq[INTR_IDX_RDPTR];
> > >      irq->name = "pp_rd_ptr";
> > >      irq->intr_idx = INTR_IDX_RDPTR;
> > > -    irq->cb.func = dpu_encoder_phys_cmd_pp_rd_ptr_irq;
> > > +    irq->func = dpu_encoder_phys_cmd_pp_rd_ptr_irq;
> > >
> > >      irq = &phys_enc->irq[INTR_IDX_UNDERRUN];
> > >      irq->name = "underrun";
> > >      irq->intr_idx = INTR_IDX_UNDERRUN;
> > > -    irq->cb.func = dpu_encoder_phys_cmd_underrun_irq;
> > > +    irq->func = dpu_encoder_phys_cmd_underrun_irq;
> > >
> > >      atomic_set(&phys_enc->vblank_refcount, 0);
> > >      atomic_set(&phys_enc->pending_kickoff_cnt, 0);
> > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> > > b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> > > index 185379b18572..437af231d6a4 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> > > @@ -725,20 +725,18 @@ struct dpu_encoder_phys 
> > > *dpu_encoder_phys_vid_init(
> > >      phys_enc->enc_spinlock = p->enc_spinlock;
> > >      for (i = 0; i < INTR_IDX_MAX; i++) {
> > >          irq = &phys_enc->irq[i];
> > > -        INIT_LIST_HEAD(&irq->cb.list);
> > >          irq->irq_idx = -EINVAL;
> > > -        irq->cb.arg = phys_enc;
> > >      }
> > >
> > >      irq = &phys_enc->irq[INTR_IDX_VSYNC];
> > >      irq->name = "vsync_irq";
> > >      irq->intr_idx = INTR_IDX_VSYNC;
> > > -    irq->cb.func = dpu_encoder_phys_vid_vblank_irq;
> > > +    irq->func = dpu_encoder_phys_vid_vblank_irq;
> > >
> > >      irq = &phys_enc->irq[INTR_IDX_UNDERRUN];
> > >      irq->name = "underrun";
> > >      irq->intr_idx = INTR_IDX_UNDERRUN;
> > > -    irq->cb.func = dpu_encoder_phys_vid_underrun_irq;
> > > +    irq->func = dpu_encoder_phys_vid_underrun_irq;
> > >
> > >      atomic_set(&phys_enc->vblank_refcount, 0);
> > >      atomic_set(&phys_enc->pending_kickoff_cnt, 0);
> > > 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 d2b6dca487e3..7062e7f0e860 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
> > > @@ -127,21 +127,17 @@ static const struct dpu_intr_reg dpu_intr_set[] 
> > > = {
> > >   */
> > >  static void dpu_core_irq_callback_handler(struct dpu_kms *dpu_kms, 
> > > int irq_idx)
> > >  {
> > > -    struct dpu_irq_callback *cb;
> > > -
> > >      VERB("irq_idx=%d\n", irq_idx);
> > >
> > > -    if (list_empty(&dpu_kms->hw_intr->irq_cb_tbl[irq_idx]))
> > > +    if (!dpu_kms->hw_intr->irq_tbl[irq_idx].cb)
> > >          DRM_ERROR("no registered cb, idx:%d\n", irq_idx);
> > >
> > > -    atomic_inc(&dpu_kms->hw_intr->irq_counts[irq_idx]);
> > > +    atomic_inc(&dpu_kms->hw_intr->irq_tbl[irq_idx].count);
> > >
> > >      /*
> > >       * Perform registered function callback
> > >       */
> > > -    list_for_each_entry(cb, &dpu_kms->hw_intr->irq_cb_tbl[irq_idx], 
> > > list)
> > > -        if (cb->func)
> > > -            cb->func(cb->arg, 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 dpu_kms *dpu_kms)
> > > @@ -389,24 +385,18 @@ struct dpu_hw_intr *dpu_hw_intr_init(void 
> > > __iomem *addr,
> > >          struct dpu_mdss_cfg *m)
> > >  {
> > >      struct dpu_hw_intr *intr;
> > > +    int nirq = MDP_INTR_MAX * 32;
> > >
> > >      if (!addr || !m)
> > >          return ERR_PTR(-EINVAL);
> > >
> > > -    intr = kzalloc(sizeof(*intr), GFP_KERNEL);
> > > +    intr = kzalloc(struct_size(intr, irq_tbl, nirq), GFP_KERNEL);
> > >      if (!intr)
> > >          return ERR_PTR(-ENOMEM);
> > >
> > >      __intr_offset(m, addr, &intr->hw);
> > >
> > > -    intr->total_irqs = ARRAY_SIZE(dpu_intr_set) * 32;
> > > -
> > > -    intr->cache_irq_mask = kcalloc(ARRAY_SIZE(dpu_intr_set), 
> > > sizeof(u32),
> > > -            GFP_KERNEL);
> > > -    if (intr->cache_irq_mask == NULL) {
> > > -        kfree(intr);
> > > -        return ERR_PTR(-ENOMEM);
> > > -    }
> > > +    intr->total_irqs = nirq;
> > >
> > >      intr->irq_mask = m->mdss_irqs;
> > >
> > > @@ -417,31 +407,19 @@ struct dpu_hw_intr *dpu_hw_intr_init(void 
> > > __iomem *addr,
> > >
> > >  void dpu_hw_intr_destroy(struct dpu_hw_intr *intr)
> > >  {
> > > -    if (intr) {
> > > -        kfree(intr->cache_irq_mask);
> > > -
> > > -        kfree(intr->irq_cb_tbl);
> > > -        kfree(intr->irq_counts);
> > > -
> > > +    if (intr)
> > >          kfree(intr);
> > > -    }
> > >  }
> > >
> > >  int dpu_core_irq_register_callback(struct dpu_kms *dpu_kms, int 
> > > irq_idx,
> > > -        struct dpu_irq_callback *register_irq_cb)
> > > +        void (*irq_cb)(void *arg, int irq_idx),
> > > +        void *irq_arg)
> > >  {
> > >      unsigned long irq_flags;
> > > +    int ret;
> > >
> > > -    if (!dpu_kms->hw_intr->irq_cb_tbl) {
> > > -        DPU_ERROR("invalid params\n");
> > > -        return -EINVAL;
> > > -    }
> > > -
> > > -    if (!register_irq_cb || !register_irq_cb->func) {
> > > -        DPU_ERROR("invalid irq_cb:%d func:%d\n",
> > > -                register_irq_cb != NULL,
> > > -                register_irq_cb ?
> > > -                    register_irq_cb->func != NULL : -1);
> > > +    if (!irq_cb) {
> > > +        DPU_ERROR("invalid ird_idx:%d irq_cb:%ps\n", irq_idx, irq_cb);
> > >          return -EINVAL;
> > >      }
> > >
> > > @@ -453,39 +431,37 @@ int dpu_core_irq_register_callback(struct
> > > dpu_kms *dpu_kms, int irq_idx,
> > >      VERB("[%pS] irq_idx=%d\n", __builtin_return_address(0), irq_idx);
> > >
> > >      spin_lock_irqsave(&dpu_kms->hw_intr->irq_lock, irq_flags);
> > > -    trace_dpu_core_irq_register_callback(irq_idx, register_irq_cb);
> > > -    list_del_init(&register_irq_cb->list);
> > > -    list_add_tail(&register_irq_cb->list,
> > > -            &dpu_kms->hw_intr->irq_cb_tbl[irq_idx]);
> > > -    if (list_is_first(&register_irq_cb->list,
> > > -            &dpu_kms->hw_intr->irq_cb_tbl[irq_idx])) {
> > > -        int ret = dpu_hw_intr_enable_irq_locked(
> > > +
> > > +    if (dpu_kms->hw_intr->irq_tbl[irq_idx].cb) {
> > > +        spin_unlock_irqrestore(&dpu_kms->hw_intr->irq_lock, irq_flags);
> > > +
> > > +        return -EBUSY;
> > > +    }
> > Why is this check present? Ideally there should be only one callback 
> > registered.

There should be one callback registered. However I'd prefer to be safe 
than sorry and to warn if somebody attempts to register a second 
callback here.

> > > +
> > > +    trace_dpu_core_irq_register_callback(irq_idx, irq_cb);
> > > +    dpu_kms->hw_intr->irq_tbl[irq_idx].arg = irq_arg;
> > > +    dpu_kms->hw_intr->irq_tbl[irq_idx].cb = irq_cb;
> > > +
> > > +    ret = dpu_hw_intr_enable_irq_locked(
> > >                  dpu_kms->hw_intr,
> > >                  irq_idx);
> > > -        if (ret)
> > > -            DPU_ERROR("Fail to enable IRQ for irq_idx:%d\n",
> > > +    if (ret)
> > > +        DPU_ERROR("Fail to enable IRQ for irq_idx:%d\n",
> > >                      irq_idx);
> > > -    }
> > >      spin_unlock_irqrestore(&dpu_kms->hw_intr->irq_lock, irq_flags);
> > >
> > >      return 0;
> > >  }
> > >
> > >  int dpu_core_irq_unregister_callback(struct dpu_kms *dpu_kms, int 
> > > irq_idx,
> > > -        struct dpu_irq_callback *register_irq_cb)
> > > +        void (*irq_cb)(void *arg, int irq_idx),
> > > +        void *irq_arg)
> > >  {
> > >      unsigned long irq_flags;
> > > +    int ret;
> > >
> > > -    if (!dpu_kms->hw_intr->irq_cb_tbl) {
> > > -        DPU_ERROR("invalid params\n");
> > > -        return -EINVAL;
> > > -    }
> > > -
> > > -    if (!register_irq_cb || !register_irq_cb->func) {
> > > -        DPU_ERROR("invalid irq_cb:%d func:%d\n",
> > > -                register_irq_cb != NULL,
> > > -                register_irq_cb ?
> > > -                    register_irq_cb->func != NULL : -1);
> > > +    if (!irq_cb) {
> > > +        DPU_ERROR("invalid ird_idx:%d irq_cb:%ps\n", irq_idx, irq_cb);
> > >          return -EINVAL;
> > >      }
> > >
> > > @@ -497,18 +473,23 @@ int dpu_core_irq_unregister_callback(struct
> > > dpu_kms *dpu_kms, int irq_idx,
> > >      VERB("[%pS] irq_idx=%d\n", __builtin_return_address(0), irq_idx);
> > >
> > >      spin_lock_irqsave(&dpu_kms->hw_intr->irq_lock, irq_flags);
> > > -    trace_dpu_core_irq_unregister_callback(irq_idx, register_irq_cb);
> > > -    list_del_init(&register_irq_cb->list);
> > > -    /* empty callback list but interrupt is still enabled */
> > > -    if (list_empty(&dpu_kms->hw_intr->irq_cb_tbl[irq_idx])) {
> > > -        int ret = dpu_hw_intr_disable_irq_locked(
> > > -                dpu_kms->hw_intr,
> > > -                irq_idx);
> > > -        if (ret)
> > > -            DPU_ERROR("Fail to disable IRQ for irq_idx:%d\n",
> > > -                    irq_idx);
> > > -        VERB("irq_idx=%d ret=%d\n", irq_idx, ret);
> > > +    trace_dpu_core_irq_unregister_callback(irq_idx, irq_cb);
> > > +
> > > +    if (WARN_ON(dpu_kms->hw_intr->irq_tbl[irq_idx].cb != irq_cb ||
> > > +            dpu_kms->hw_intr->irq_tbl[irq_idx].arg != irq_arg)) {
> > > +        spin_unlock_irqrestore(&dpu_kms->hw_intr->irq_lock, irq_flags);
> > > +
> > > +        return -EINVAL;
> > >      }
> >
> > Why do we need this check too? Any condition where this wont match?

No, we can drop this.

> > > +
> > > +    ret = dpu_hw_intr_disable_irq_locked(dpu_kms->hw_intr, irq_idx);
> > > +    if (ret)
> > > +        DPU_ERROR("Fail to disable IRQ for irq_idx:%d: %d\n",
> > > +                    irq_idx, ret);
> > > +
> > > +    dpu_kms->hw_intr->irq_tbl[irq_idx].cb = NULL;
> > > +    dpu_kms->hw_intr->irq_tbl[irq_idx].arg = NULL;
> > > +
> > >      spin_unlock_irqrestore(&dpu_kms->hw_intr->irq_lock, irq_flags);
> > >
> > >      return 0;
> > > @@ -518,24 +499,18 @@ int dpu_core_irq_unregister_callback(struct
> > > dpu_kms *dpu_kms, int irq_idx,
> > >  static int dpu_debugfs_core_irq_show(struct seq_file *s, void *v)
> > >  {
> > >      struct dpu_kms *dpu_kms = s->private;
> > > -    struct dpu_irq_callback *cb;
> > >      unsigned long irq_flags;
> > > -    int i, irq_count, cb_count;
> > > -
> > > -    if (WARN_ON(!dpu_kms->hw_intr->irq_cb_tbl))
> > > -        return 0;
> > > +    int i, irq_count;
> > > +    void *cb;
> > >
> > >      for (i = 0; i < dpu_kms->hw_intr->total_irqs; i++) {
> > >          spin_lock_irqsave(&dpu_kms->hw_intr->irq_lock, irq_flags);
> > > -        cb_count = 0;
> > > -        irq_count = atomic_read(&dpu_kms->hw_intr->irq_counts[i]);
> > > -        list_for_each_entry(cb, &dpu_kms->hw_intr->irq_cb_tbl[i], list)
> > > -            cb_count++;
> > > +        irq_count = atomic_read(&dpu_kms->hw_intr->irq_tbl[i].count);
> > > +        cb = dpu_kms->hw_intr->irq_tbl[i].cb;
> > >          spin_unlock_irqrestore(&dpu_kms->hw_intr->irq_lock, irq_flags);
> > >
> > > -        if (irq_count || cb_count)
> > > -            seq_printf(s, "idx:%d irq:%d cb:%d\n",
> > > -                    i, irq_count, cb_count);
> > > +        if (irq_count || cb)
> > > +            seq_printf(s, "idx:%d irq:%d cb:%ps\n", i, irq_count, cb);
> > >      }
> > >
> > >      return 0;
> > > @@ -560,15 +535,8 @@ void dpu_core_irq_preinstall(struct dpu_kms 
> > > *dpu_kms)
> > >      dpu_disable_all_irqs(dpu_kms);
> > >      pm_runtime_put_sync(&dpu_kms->pdev->dev);
> > >
> > > -    /* Create irq callbacks for all possible irq_idx */
> > > -    dpu_kms->hw_intr->irq_cb_tbl = 
> > > kcalloc(dpu_kms->hw_intr->total_irqs,
> > > -            sizeof(struct list_head), GFP_KERNEL);
> > > -    dpu_kms->hw_intr->irq_counts = 
> > > kcalloc(dpu_kms->hw_intr->total_irqs,
> > > -            sizeof(atomic_t), GFP_KERNEL);
> > > -    for (i = 0; i < dpu_kms->hw_intr->total_irqs; i++) {
> > > -        INIT_LIST_HEAD(&dpu_kms->hw_intr->irq_cb_tbl[i]);
> > > -        atomic_set(&dpu_kms->hw_intr->irq_counts[i], 0);
> > > -    }
> > > +    for (i = 0; i < dpu_kms->hw_intr->total_irqs; i++)
> > > +        atomic_set(&dpu_kms->hw_intr->irq_tbl[i].count, 0);
> > >  }
> > >
> > >  void dpu_core_irq_uninstall(struct dpu_kms *dpu_kms)
> > > @@ -577,7 +545,7 @@ void dpu_core_irq_uninstall(struct dpu_kms *dpu_kms)
> > >
> > >      pm_runtime_get_sync(&dpu_kms->pdev->dev);
> > >      for (i = 0; i < dpu_kms->hw_intr->total_irqs; i++)
> > > -        if (!list_empty(&dpu_kms->hw_intr->irq_cb_tbl[i]))
> > > +        if (dpu_kms->hw_intr->irq_tbl[i].cb)
> > >              DPU_ERROR("irq_idx=%d still enabled/registered\n", i);
> > >
> > >      dpu_clear_irqs(dpu_kms);
> > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h
> > > b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h
> > > index d50e78c9f148..9855e176b173 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h
> > > @@ -40,19 +40,21 @@ enum dpu_hw_intr_reg {
> > >   * @save_irq_status:  array of IRQ status reg storage created during 
> > > init
> > >   * @total_irqs: total number of irq_idx mapped in the hw_interrupts
> > >   * @irq_lock:         spinlock for accessing IRQ resources
> > > - * @irq_cb_tbl:       array of IRQ callbacks lists
> > > - * @irq_counts:       array of IRQ counts
> > > + * @irq_cb_tbl:       array of IRQ callbacks
> > >   */
> > >  struct dpu_hw_intr {
> > >      struct dpu_hw_blk_reg_map hw;
> > > -    u32 *cache_irq_mask;
> > > +    u32 cache_irq_mask[MDP_INTR_MAX];
> > >      u32 *save_irq_status;
> > >      u32 total_irqs;
> > >      spinlock_t irq_lock;
> > >      unsigned long irq_mask;
> > >
> > > -    struct list_head *irq_cb_tbl;
> > > -    atomic_t *irq_counts;
> > > +    struct {
> > > +        void (*cb)(void *arg, int irq_idx);
> > > +        void *arg;
> > > +        atomic_t count;
> > > +    } irq_tbl[];
> > >  };
> > >
> > >  /**
> > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> > > b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> > > index 775bcbda860f..d24dcd852d2e 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> > > @@ -66,18 +66,6 @@
> > >
> > >  #define DPU_NAME_SIZE  12
> > >
> > > -/*
> > > - * struct dpu_irq_callback - IRQ callback handlers
> > > - * @list: list to callback
> > > - * @func: intr handler
> > > - * @arg: argument for the handler
> > > - */
> > > -struct dpu_irq_callback {
> > > -    struct list_head list;
> > > -    void (*func)(void *arg, int irq_idx);
> > > -    void *arg;
> > > -};
> > > -
> > >  struct dpu_kms {
> > >      struct msm_kms base;
> > >      struct drm_device *dev;
> > > diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_trace.h
> > > b/drivers/gpu/drm/msm/disp/dpu1/dpu_trace.h
> > > index 37bba57675a8..1e2619556f93 100644
> > > --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_trace.h
> > > +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_trace.h
> > > @@ -876,25 +876,25 @@ TRACE_EVENT(dpu_pp_connect_ext_te,
> > >  );
> > >
> > >  DECLARE_EVENT_CLASS(dpu_core_irq_callback_template,
> > > -    TP_PROTO(int irq_idx, struct dpu_irq_callback *callback),
> > > +    TP_PROTO(int irq_idx, void *callback),
> > >      TP_ARGS(irq_idx, callback),
> > >      TP_STRUCT__entry(
> > >          __field(    int,                irq_idx    )
> > > -        __field(    struct dpu_irq_callback *,    callback)
> > > +        __field(    void *,                callback)
> > >      ),
> > >      TP_fast_assign(
> > >          __entry->irq_idx = irq_idx;
> > >          __entry->callback = callback;
> > >      ),
> > > -    TP_printk("irq_idx:%d callback:%pK", __entry->irq_idx,
> > > +    TP_printk("irq_idx:%d callback:%ps", __entry->irq_idx,
> > >            __entry->callback)
> > >  );
> > >  DEFINE_EVENT(dpu_core_irq_callback_template, 
> > > dpu_core_irq_register_callback,
> > > -    TP_PROTO(int irq_idx, struct dpu_irq_callback *callback),
> > > +    TP_PROTO(int irq_idx, void *callback),
> > >      TP_ARGS(irq_idx, callback)
> > >  );
> > >  DEFINE_EVENT(dpu_core_irq_callback_template, 
> > > dpu_core_irq_unregister_callback,
> > > -    TP_PROTO(int irq_idx, struct dpu_irq_callback *callback),
> > > +    TP_PROTO(int irq_idx, void *callback),
> > >      TP_ARGS(irq_idx, callback)
> > >  );


--
With best wishes
Dmitry