Re: [PATCH v1 3/3] drm/msm/dpu: simplify interrupt managing

Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx> · Sun, 16 May 2021 23:35:23 +0300

On 16/05/2021 08:24, Bjorn Andersson wrote:
On Sun 11 Apr 19:09 CDT 2021, Dmitry Baryshkov wrote:

Change huge lookup table to contain just sensible entries. IRQ index is
now not an index in the table, but just register id (multiplied by 32,
the amount of IRQs in the register) plus offset in the register. This
allows us to remove all the "reserved" entries from dpu_irq_map. The
table is now only used for lookups, individual functions calculate
register and mask using the irq_idx.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
  drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c  |   10 +-
  .../gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c | 1151 +++--------------
  .../gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.h |    4 +-
  3 files changed, 196 insertions(+), 969 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c
index fd11a2aeab6c..4e2ad03df903 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_irq.c
@@ -70,7 +70,7 @@ static int _dpu_core_irq_enable(struct dpu_kms *dpu_kms, int irq_idx)
  		return -EINVAL;
  	}
  
-	if (irq_idx < 0 || irq_idx >= dpu_kms->hw_intr->irq_idx_tbl_size) {
+	if (irq_idx < 0 || irq_idx >= dpu_kms->hw_intr->total_irqs) {
  		DPU_ERROR("invalid IRQ index: [%d]\n", irq_idx);
  		return -EINVAL;
  	}
@@ -133,7 +133,7 @@ static int _dpu_core_irq_disable(struct dpu_kms *dpu_kms, int irq_idx)
  		return -EINVAL;
  	}
  
-	if (irq_idx < 0 || irq_idx >= dpu_kms->hw_intr->irq_idx_tbl_size) {
+	if (irq_idx < 0 || irq_idx >= dpu_kms->hw_intr->total_irqs) {
  		DPU_ERROR("invalid IRQ index: [%d]\n", irq_idx);
  		return -EINVAL;
  	}
@@ -208,7 +208,7 @@ int dpu_core_irq_register_callback(struct dpu_kms *dpu_kms, int irq_idx,
  		return -EINVAL;
  	}
  
-	if (irq_idx < 0 || irq_idx >= dpu_kms->hw_intr->irq_idx_tbl_size) {
+	if (irq_idx < 0 || irq_idx >= dpu_kms->hw_intr->total_irqs) {
  		DPU_ERROR("invalid IRQ index: [%d]\n", irq_idx);
  		return -EINVAL;
  	}
@@ -243,7 +243,7 @@ int dpu_core_irq_unregister_callback(struct dpu_kms *dpu_kms, int irq_idx,
  		return -EINVAL;
  	}
  
-	if (irq_idx < 0 || irq_idx >= dpu_kms->hw_intr->irq_idx_tbl_size) {
+	if (irq_idx < 0 || irq_idx >= dpu_kms->hw_intr->total_irqs) {
  		DPU_ERROR("invalid IRQ index: [%d]\n", irq_idx);
  		return -EINVAL;
  	}
@@ -328,7 +328,7 @@ void dpu_core_irq_preinstall(struct dpu_kms *dpu_kms)
  	spin_lock_init(&dpu_kms->irq_obj.cb_lock);
  
  	/* Create irq callbacks for all possible irq_idx */
-	dpu_kms->irq_obj.total_irqs = dpu_kms->hw_intr->irq_idx_tbl_size;
+	dpu_kms->irq_obj.total_irqs = dpu_kms->hw_intr->total_irqs;
  	dpu_kms->irq_obj.irq_cb_tbl = kcalloc(dpu_kms->irq_obj.total_irqs,
  			sizeof(struct list_head), GFP_KERNEL);
  	dpu_kms->irq_obj.enable_counts = kcalloc(dpu_kms->irq_obj.total_irqs,
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 8bd22e060437..2cb6800047c3 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_interrupts.c
@@ -32,142 +32,142 @@
  /**
   * WB interrupt status bit definitions
   */
-#define DPU_INTR_WB_0_DONE BIT(0)
-#define DPU_INTR_WB_1_DONE BIT(1)
-#define DPU_INTR_WB_2_DONE BIT(4)
+#define DPU_INTR_WB_0_DONE	0
+#define DPU_INTR_WB_1_DONE	1
+#define DPU_INTR_WB_2_DONE	4
  
  /**
   * WDOG timer interrupt status bit definitions
   */
-#define DPU_INTR_WD_TIMER_0_DONE BIT(2)
-#define DPU_INTR_WD_TIMER_1_DONE BIT(3)
-#define DPU_INTR_WD_TIMER_2_DONE BIT(5)
-#define DPU_INTR_WD_TIMER_3_DONE BIT(6)
-#define DPU_INTR_WD_TIMER_4_DONE BIT(7)
+#define DPU_INTR_WD_TIMER_0_DONE	2
+#define DPU_INTR_WD_TIMER_1_DONE	3
+#define DPU_INTR_WD_TIMER_2_DONE	5
+#define DPU_INTR_WD_TIMER_3_DONE	6
+#define DPU_INTR_WD_TIMER_4_DONE	7
  
  /**
   * Pingpong interrupt status bit definitions
   */
-#define DPU_INTR_PING_PONG_0_DONE BIT(8)
-#define DPU_INTR_PING_PONG_1_DONE BIT(9)
-#define DPU_INTR_PING_PONG_2_DONE BIT(10)
-#define DPU_INTR_PING_PONG_3_DONE BIT(11)
-#define DPU_INTR_PING_PONG_0_RD_PTR BIT(12)
-#define DPU_INTR_PING_PONG_1_RD_PTR BIT(13)
-#define DPU_INTR_PING_PONG_2_RD_PTR BIT(14)
-#define DPU_INTR_PING_PONG_3_RD_PTR BIT(15)
-#define DPU_INTR_PING_PONG_0_WR_PTR BIT(16)
-#define DPU_INTR_PING_PONG_1_WR_PTR BIT(17)
-#define DPU_INTR_PING_PONG_2_WR_PTR BIT(18)
-#define DPU_INTR_PING_PONG_3_WR_PTR BIT(19)
-#define DPU_INTR_PING_PONG_0_AUTOREFRESH_DONE BIT(20)
-#define DPU_INTR_PING_PONG_1_AUTOREFRESH_DONE BIT(21)
-#define DPU_INTR_PING_PONG_2_AUTOREFRESH_DONE BIT(22)
-#define DPU_INTR_PING_PONG_3_AUTOREFRESH_DONE BIT(23)
+#define DPU_INTR_PING_PONG_0_DONE	8
+#define DPU_INTR_PING_PONG_1_DONE	9
+#define DPU_INTR_PING_PONG_2_DONE	10
+#define DPU_INTR_PING_PONG_3_DONE	11
+#define DPU_INTR_PING_PONG_0_RD_PTR	12
+#define DPU_INTR_PING_PONG_1_RD_PTR	13
+#define DPU_INTR_PING_PONG_2_RD_PTR	14
+#define DPU_INTR_PING_PONG_3_RD_PTR	15
+#define DPU_INTR_PING_PONG_0_WR_PTR	16
+#define DPU_INTR_PING_PONG_1_WR_PTR	17
+#define DPU_INTR_PING_PONG_2_WR_PTR	18
+#define DPU_INTR_PING_PONG_3_WR_PTR	19
+#define DPU_INTR_PING_PONG_0_AUTOREFRESH_DONE	20
+#define DPU_INTR_PING_PONG_1_AUTOREFRESH_DONE	21
+#define DPU_INTR_PING_PONG_2_AUTOREFRESH_DONE	22
+#define DPU_INTR_PING_PONG_3_AUTOREFRESH_DONE	23
  
  /**
   * Interface interrupt status bit definitions
   */
-#define DPU_INTR_INTF_0_UNDERRUN BIT(24)
-#define DPU_INTR_INTF_1_UNDERRUN BIT(26)
-#define DPU_INTR_INTF_2_UNDERRUN BIT(28)
-#define DPU_INTR_INTF_3_UNDERRUN BIT(30)
-#define DPU_INTR_INTF_5_UNDERRUN BIT(22)
-#define DPU_INTR_INTF_0_VSYNC BIT(25)
-#define DPU_INTR_INTF_1_VSYNC BIT(27)
-#define DPU_INTR_INTF_2_VSYNC BIT(29)
-#define DPU_INTR_INTF_3_VSYNC BIT(31)
-#define DPU_INTR_INTF_5_VSYNC BIT(23)
+#define DPU_INTR_INTF_0_UNDERRUN	24
+#define DPU_INTR_INTF_1_UNDERRUN	26
+#define DPU_INTR_INTF_2_UNDERRUN	28
+#define DPU_INTR_INTF_3_UNDERRUN	30
+#define DPU_INTR_INTF_5_UNDERRUN	22
+#define DPU_INTR_INTF_0_VSYNC	25
+#define DPU_INTR_INTF_1_VSYNC	27
+#define DPU_INTR_INTF_2_VSYNC	29
+#define DPU_INTR_INTF_3_VSYNC	31
+#define DPU_INTR_INTF_5_VSYNC	23
  
  /**
   * Pingpong Secondary interrupt status bit definitions
   */
-#define DPU_INTR_PING_PONG_S0_AUTOREFRESH_DONE BIT(0)
-#define DPU_INTR_PING_PONG_S0_WR_PTR BIT(4)
-#define DPU_INTR_PING_PONG_S0_RD_PTR BIT(8)
-#define DPU_INTR_PING_PONG_S0_TEAR_DETECTED BIT(22)
-#define DPU_INTR_PING_PONG_S0_TE_DETECTED BIT(28)
+#define DPU_INTR_PING_PONG_S0_AUTOREFRESH_DONE	0
+#define DPU_INTR_PING_PONG_S0_WR_PTR	4
+#define DPU_INTR_PING_PONG_S0_RD_PTR	8
+#define DPU_INTR_PING_PONG_S0_TEAR_DETECTED	22
+#define DPU_INTR_PING_PONG_S0_TE_DETECTED	28
  
  /**
   * Pingpong TEAR detection interrupt status bit definitions
   */
-#define DPU_INTR_PING_PONG_0_TEAR_DETECTED BIT(16)
-#define DPU_INTR_PING_PONG_1_TEAR_DETECTED BIT(17)
-#define DPU_INTR_PING_PONG_2_TEAR_DETECTED BIT(18)
-#define DPU_INTR_PING_PONG_3_TEAR_DETECTED BIT(19)
+#define DPU_INTR_PING_PONG_0_TEAR_DETECTED	16
+#define DPU_INTR_PING_PONG_1_TEAR_DETECTED	17
+#define DPU_INTR_PING_PONG_2_TEAR_DETECTED	18
+#define DPU_INTR_PING_PONG_3_TEAR_DETECTED	19
  
  /**
   * Pingpong TE detection interrupt status bit definitions
   */
-#define DPU_INTR_PING_PONG_0_TE_DETECTED BIT(24)
-#define DPU_INTR_PING_PONG_1_TE_DETECTED BIT(25)
-#define DPU_INTR_PING_PONG_2_TE_DETECTED BIT(26)
-#define DPU_INTR_PING_PONG_3_TE_DETECTED BIT(27)
+#define DPU_INTR_PING_PONG_0_TE_DETECTED	24
+#define DPU_INTR_PING_PONG_1_TE_DETECTED	25
+#define DPU_INTR_PING_PONG_2_TE_DETECTED	26
+#define DPU_INTR_PING_PONG_3_TE_DETECTED	27
  
  /**
   * Ctl start interrupt status bit definitions
   */
-#define DPU_INTR_CTL_0_START BIT(9)
-#define DPU_INTR_CTL_1_START BIT(10)
-#define DPU_INTR_CTL_2_START BIT(11)
-#define DPU_INTR_CTL_3_START BIT(12)
-#define DPU_INTR_CTL_4_START BIT(13)
+#define DPU_INTR_CTL_0_START	9
+#define DPU_INTR_CTL_1_START	10
+#define DPU_INTR_CTL_2_START	11
+#define DPU_INTR_CTL_3_START	12
+#define DPU_INTR_CTL_4_START	13
  
  /**
   * Concurrent WB overflow interrupt status bit definitions
   */
-#define DPU_INTR_CWB_2_OVERFLOW BIT(14)
-#define DPU_INTR_CWB_3_OVERFLOW BIT(15)
+#define DPU_INTR_CWB_2_OVERFLOW	14
+#define DPU_INTR_CWB_3_OVERFLOW	15
  
  /**
   * Histogram VIG done interrupt status bit definitions
   */
-#define DPU_INTR_HIST_VIG_0_DONE BIT(0)
-#define DPU_INTR_HIST_VIG_1_DONE BIT(4)
-#define DPU_INTR_HIST_VIG_2_DONE BIT(8)
-#define DPU_INTR_HIST_VIG_3_DONE BIT(10)
+#define DPU_INTR_HIST_VIG_0_DONE	0
+#define DPU_INTR_HIST_VIG_1_DONE	4
+#define DPU_INTR_HIST_VIG_2_DONE	8
+#define DPU_INTR_HIST_VIG_3_DONE	10
  
  /**
   * Histogram VIG reset Sequence done interrupt status bit definitions
   */
-#define DPU_INTR_HIST_VIG_0_RSTSEQ_DONE BIT(1)
-#define DPU_INTR_HIST_VIG_1_RSTSEQ_DONE BIT(5)
-#define DPU_INTR_HIST_VIG_2_RSTSEQ_DONE BIT(9)
-#define DPU_INTR_HIST_VIG_3_RSTSEQ_DONE BIT(11)
+#define DPU_INTR_HIST_VIG_0_RSTSEQ_DONE	1
+#define DPU_INTR_HIST_VIG_1_RSTSEQ_DONE	5
+#define DPU_INTR_HIST_VIG_2_RSTSEQ_DONE	9
+#define DPU_INTR_HIST_VIG_3_RSTSEQ_DONE	11
  
  /**
   * Histogram DSPP done interrupt status bit definitions
   */
-#define DPU_INTR_HIST_DSPP_0_DONE BIT(12)
-#define DPU_INTR_HIST_DSPP_1_DONE BIT(16)
-#define DPU_INTR_HIST_DSPP_2_DONE BIT(20)
-#define DPU_INTR_HIST_DSPP_3_DONE BIT(22)
+#define DPU_INTR_HIST_DSPP_0_DONE	12
+#define DPU_INTR_HIST_DSPP_1_DONE	16
+#define DPU_INTR_HIST_DSPP_2_DONE	20
+#define DPU_INTR_HIST_DSPP_3_DONE	22
  
  /**
   * Histogram DSPP reset Sequence done interrupt status bit definitions
   */
-#define DPU_INTR_HIST_DSPP_0_RSTSEQ_DONE BIT(13)
-#define DPU_INTR_HIST_DSPP_1_RSTSEQ_DONE BIT(17)
-#define DPU_INTR_HIST_DSPP_2_RSTSEQ_DONE BIT(21)
-#define DPU_INTR_HIST_DSPP_3_RSTSEQ_DONE BIT(23)
+#define DPU_INTR_HIST_DSPP_0_RSTSEQ_DONE	13
+#define DPU_INTR_HIST_DSPP_1_RSTSEQ_DONE	17
+#define DPU_INTR_HIST_DSPP_2_RSTSEQ_DONE	21
+#define DPU_INTR_HIST_DSPP_3_RSTSEQ_DONE	23
  
  /**
   * INTF interrupt status bit definitions
   */
-#define DPU_INTR_VIDEO_INTO_STATIC BIT(0)
-#define DPU_INTR_VIDEO_OUTOF_STATIC BIT(1)
-#define DPU_INTR_DSICMD_0_INTO_STATIC BIT(2)
-#define DPU_INTR_DSICMD_0_OUTOF_STATIC BIT(3)
-#define DPU_INTR_DSICMD_1_INTO_STATIC BIT(4)
-#define DPU_INTR_DSICMD_1_OUTOF_STATIC BIT(5)
-#define DPU_INTR_DSICMD_2_INTO_STATIC BIT(6)
-#define DPU_INTR_DSICMD_2_OUTOF_STATIC BIT(7)
-#define DPU_INTR_PROG_LINE BIT(8)
+#define DPU_INTR_VIDEO_INTO_STATIC	0
+#define DPU_INTR_VIDEO_OUTOF_STATIC	1
+#define DPU_INTR_DSICMD_0_INTO_STATIC	2
+#define DPU_INTR_DSICMD_0_OUTOF_STATIC	3
+#define DPU_INTR_DSICMD_1_INTO_STATIC	4
+#define DPU_INTR_DSICMD_1_OUTOF_STATIC	5
+#define DPU_INTR_DSICMD_2_INTO_STATIC	6
+#define DPU_INTR_DSICMD_2_OUTOF_STATIC	7
+#define DPU_INTR_PROG_LINE		8
  
  /**
   * AD4 interrupt status bit definitions
   */
-#define DPU_INTR_BACKLIGHT_UPDATED BIT(0)
+#define DPU_INTR_BACKLIGHT_UPDATED	0
  /**
   * struct dpu_intr_reg - array of DPU register sets
   * @clr_off:	offset to CLEAR reg
@@ -184,13 +184,13 @@ struct dpu_intr_reg {
   * struct dpu_irq_type - maps each irq with i/f
   * @intr_type:		type of interrupt listed in dpu_intr_type
   * @instance_idx:	instance index of the associated HW block in DPU
- * @irq_mask:		corresponding bit in the interrupt status reg
+ * @irq_offset:		corresponding bit in the interrupt status reg
   * @reg_idx:		which reg set to use
   */
  struct dpu_irq_type {
  	u32 intr_type;
  	u32 instance_idx;
-	u32 irq_mask;
+	u32 irq_offset;
  	u32 reg_idx;
  };
  
@@ -265,6 +265,10 @@ static const struct dpu_intr_reg dpu_intr_set[] = {
  	},
  };
  
+#define DPU_IRQ_IDX(reg_idx, offset)	(reg_idx * 32 + offset)
+#define DPU_IRQ_REG(irq_idx)	(irq_idx / 32)
+#define DPU_IRQ_MASK(irq_idx)	(BIT(irq_idx % 32))
+
  /*
   * struct dpu_irq_type - IRQ mapping table use for lookup an irq_idx in this
   *			 table that have a matching interface type and
@@ -328,59 +332,20 @@ static const struct dpu_irq_type dpu_irq_map[] = {
  	{ DPU_IRQ_TYPE_INTF_VSYNC, INTF_2, DPU_INTR_INTF_2_VSYNC, 0},
  	{ DPU_IRQ_TYPE_INTF_UNDER_RUN, INTF_3, DPU_INTR_INTF_3_UNDERRUN, 0},
  	{ DPU_IRQ_TYPE_INTF_VSYNC, INTF_3, DPU_INTR_INTF_3_VSYNC, 0},
-	/* irq_idx:32-33 */
+	/* irq_idx: 22,23, changed for sc7x80 */

Afaict there are 32 items before this in the array, so per your commit
message this would represent BIT(0) in the MDP_SSPP_TOP0:INTR2, but
these are BIT(22) and BIT(33) in the first INTR register.

Unfortunately index 22 and 23 are already taken and in my sc8180x code I
thought the INTF_5 bits had moved and overwrote the PINGPONG ones.

But that is not the case and what I now realize is that we have
duplicate entries in the list for these two bits - e.g.
DPU_INTR_PING_PONG_2_AUTOREFRESH_DONE and DPU_INTR_INTF_5_UNDERRUN both
define the interrupt for BIT(22) in the first INTR register.

The way that sc7180 ensures that INTF_5 is considered is to include
DPU_IRQ_TYPE_PING_PONG_AUTO_REF in obsolete_irq of struct dpu_mdss_cfg.
So the search code will jump over the first match and later find the
entry for INTF_5 - and we have 34 "possible" bits in the first INTR.


As such, your approach will unfortunately not work to describe the old
and the new register layout. Further more the design would not be able
to cope with a bit moving within a register.


I think we instead should register the list of interrupts from the hw
catalog.

We should be able to describe each register as a {clear, enable, status}
offset and an array of 32 entries, where the index denotes the BIT() in
the register. Then we describe a given platform as a list of references
to such register objects. Older targets would include
sdm845_sspp_top0_intr in their list and newer ones
sc7180_sspp_top0_intr.

I've implemented my thoughts on this in v2 of this patchset, squashing 
it with this patch (to remove rewriting of the table destined to be 
dropped in the next patch).

That way we will avoid this obfuscated patchwork that mdss_irqs and
obsolete_irq gives us.

Reards,
Bjorn

  	{ DPU_IRQ_TYPE_INTF_UNDER_RUN, INTF_5, DPU_INTR_INTF_5_UNDERRUN, 0},
  	{ DPU_IRQ_TYPE_INTF_VSYNC, INTF_5, DPU_INTR_INTF_5_VSYNC, 0},
[skipped the rest of the patch]

--
With best wishes
Dmitry






