> -----Original Message-----
> From: dri-devel <dri-devel-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of
> Arun R Murthy
> Sent: Wednesday, September 25, 2024 8:38 PM
> To: intel-xe@xxxxxxxxxxxxxxxxxxxxx; intel-gfx@xxxxxxxxxxxxxxxxxxxxx; dri-
> devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: Murthy, Arun R <arun.r.murthy@xxxxxxxxx>
> Subject: [PATCHv4 4/7] drm/i915/histogram: histogram interrupt handling
>
> Upon enabling histogram an interrupt is trigerred after the generation of the
> statistics. This patch registers the histogram interrupt and handles the
> interrupt.
>
> v2: Added intel_crtc backpointer to intel_histogram struct (Jani)
> Removed histogram_wq and instead use dev_priv->unodered_eq (Jani)
> v3: Replaced drm_i915_private with intel_display (Suraj)
> Refactored the histogram read code (Jani)
> v4: Rebased after addressing comments on patch 1
>
> Signed-off-by: Arun R Murthy <arun.r.murthy@xxxxxxxxx>
> ---
> .../gpu/drm/i915/display/intel_display_irq.c | 6 +-
> .../gpu/drm/i915/display/intel_histogram.c | 93 +++++++++++++++++++
> .../gpu/drm/i915/display/intel_histogram.h | 3 +
> drivers/gpu/drm/i915/i915_reg.h | 5 +-
> 4 files changed, 104 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_irq.c
> b/drivers/gpu/drm/i915/display/intel_display_irq.c
> index 6878dde85031..40514966a2ea 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_irq.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_irq.c
> @@ -20,6 +20,7 @@
> #include "intel_fdi_regs.h"
> #include "intel_fifo_underrun.h"
> #include "intel_gmbus.h"
> +#include "intel_histogram.h"
> #include "intel_hotplug_irq.h"
> #include "intel_pipe_crc_regs.h"
> #include "intel_pmdemand.h"
> @@ -1190,6 +1191,9 @@ void gen8_de_irq_handler(struct drm_i915_private
> *dev_priv, u32 master_ctl)
> if (iir & gen8_de_pipe_underrun_mask(dev_priv))
> intel_cpu_fifo_underrun_irq_handler(dev_priv, pipe);
>
> + if (iir & GEN9_PIPE_HISTOGRAM_EVENT)
> + intel_histogram_irq_handler(display, pipe);
> +
> fault_errors = iir & gen8_de_pipe_fault_mask(dev_priv);
> if (fault_errors)
> drm_err_ratelimited(&dev_priv->drm,
> @@ -1756,7 +1760,7 @@ void gen8_de_irq_postinstall(struct
> drm_i915_private *dev_priv)
> struct intel_uncore *uncore = &dev_priv->uncore;
>
> u32 de_pipe_masked = gen8_de_pipe_fault_mask(dev_priv) |
> - GEN8_PIPE_CDCLK_CRC_DONE;
> + GEN8_PIPE_CDCLK_CRC_DONE |
> GEN9_PIPE_HISTOGRAM_EVENT;
> u32 de_pipe_enables;
> u32 de_port_masked = gen8_de_port_aux_mask(dev_priv);
> u32 de_port_enables;
> diff --git a/drivers/gpu/drm/i915/display/intel_histogram.c
> b/drivers/gpu/drm/i915/display/intel_histogram.c
> index 86439636b490..ce2a5eae2784 100644
> --- a/drivers/gpu/drm/i915/display/intel_histogram.c
> +++ b/drivers/gpu/drm/i915/display/intel_histogram.c
> @@ -18,6 +18,8 @@
> #define HISTOGRAM_GUARDBAND_THRESHOLD_DEFAULT 300 // 3.0% of
> the pipe's current pixel count.
> #define HISTOGRAM_GUARDBAND_PRECISION_FACTOR 10000 // Precision
> factor for threshold guardband.
> #define HISTOGRAM_DEFAULT_GUARDBAND_DELAY 0x04
> +#define HISTOGRAM_BIN_READ_RETRY_COUNT 5 #define
> +HISTOGRAM_BIN_READ_DELAY 2
>
> struct intel_histogram {
> struct intel_crtc *crtc;
> @@ -27,6 +29,92 @@ struct intel_histogram {
> u32 bin_data[HISTOGRAM_BIN_COUNT];
> };
>
> +static bool intel_histogram_get_data(struct intel_crtc *intel_crtc) {
> + struct intel_display *display = to_intel_display(intel_crtc);
> + struct intel_histogram *histogram = intel_crtc->histogram;
> + u8 index, retry_count;
> + u32 dpstbin;
> +
> + index = 0;
> + retry_count = 0;
> +
> + while (index < HISTOGRAM_BIN_COUNT) {
> + dpstbin = intel_de_read(display, DPST_BIN(intel_crtc->pipe));
> + if (!(dpstbin & DPST_BIN_BUSY)) {
> + histogram->bin_data[index] = dpstbin &
> DPST_BIN_DATA_MASK;
> + index++;
> + } else {
> + /*
> + * If DPST_BIN busy bit is set, then set the
> + * DPST_CTL bin reg index to 0 and proceed
> + * from beginning.
> + */
> + retry_count++;
> + if (retry_count >
> HISTOGRAM_BIN_READ_RETRY_COUNT) {
> + drm_err(display->drm, "Histogram bin read
> failed with max retry\n");
> + return false;
> + }
> + /* Add a delay before retrying */
> + fsleep(HISTOGRAM_BIN_READ_DELAY);
Why the delay here the bspec does not mention this it does mention waiting for a vblank
After clearing DPST_CTL Register Function Select to TC which is what we should be doing
> + index = 0;
> + intel_de_rmw(display, DPST_CTL(intel_crtc->pipe),
> + DPST_CTL_BIN_REG_FUNC_SEL |
> + DPST_CTL_BIN_REG_MASK, 0);
We should probably only be doing a intel_de_write here and clearing DPST_CTL
DPST_CTL_BIN_REG_FUNC_TC will only clear the required bit since that all the bspec expects of us
Regards,
Suraj Kandpal
> + }
> + }
> + return true;
> +}
> +
> +static void intel_histogram_handle_int_work(struct work_struct *work) {
> + struct intel_histogram *histogram = container_of(work,
> + struct intel_histogram, work.work);
> + struct intel_crtc *intel_crtc = histogram->crtc;
> + struct intel_display *display = to_intel_display(intel_crtc);
> + char *histogram_event[] = {"HISTOGRAM=1", NULL};
> +
> + /*
> + * TODO: PSR to be exited while reading the Histogram data
> + * Set DPST_CTL Bin Reg function select to TC
> + * Set DPST_CTL Bin Register Index to 0
> + */
> + intel_de_rmw(display, DPST_CTL(intel_crtc->pipe),
> + DPST_CTL_BIN_REG_FUNC_SEL |
> DPST_CTL_BIN_REG_MASK, 0);
> + if (intel_histogram_get_data(intel_crtc)) {
> + /* Notify user for Histogram rediness */
Typo *readiness
> + if (kobject_uevent_env(&display->drm->primary->kdev->kobj,
> + KOBJ_CHANGE, histogram_event))
> + drm_err(display->drm,
> + "sending HISTOGRAM event failed\n");
> + }
> +
> + /* Enable histogram interrupt */
> + intel_de_rmw(display, DPST_GUARD(intel_crtc->pipe),
> DPST_GUARD_HIST_INT_EN,
> + DPST_GUARD_HIST_INT_EN);
> +
> + /* Clear histogram interrupt by setting histogram interrupt status bit*/
> + intel_de_rmw(display, DPST_GUARD(intel_crtc->pipe),
> + DPST_GUARD_HIST_EVENT_STATUS, 1); }
> +
> +void intel_histogram_irq_handler(struct intel_display *display, enum
> +pipe pipe) {
> + struct intel_crtc *intel_crtc =
> + to_intel_crtc(drm_crtc_from_index(display->drm, pipe));
> + struct intel_histogram *histogram = intel_crtc->histogram;
> + struct drm_i915_private *i915 = to_i915(intel_crtc->base.dev);
> +
> + if (!histogram->enable) {
> + drm_err(display->drm,
> + "spurious interrupt, histogram not enabled\n");
> + return;
> + }
> +
> + queue_delayed_work(i915->unordered_wq,
> + &histogram->work, 0);
> +}
> +
> int intel_histogram_atomic_check(struct intel_crtc *intel_crtc) {
> struct intel_histogram *histogram = intel_crtc->histogram; @@ -105,6
> +193,7 @@ static void intel_histogram_disable(struct intel_crtc *intel_crtc)
> intel_de_rmw(display, DPST_CTL(pipe),
> DPST_CTL_IE_HIST_EN, 0);
>
> + cancel_delayed_work(&histogram->work);
> histogram->enable = false;
> }
>
> @@ -166,6 +255,7 @@ void intel_histogram_finish(struct intel_crtc
> *intel_crtc) {
> struct intel_histogram *histogram = intel_crtc->histogram;
>
> + cancel_delayed_work_sync(&histogram->work);
> kfree(histogram);
> }
>
> @@ -183,5 +273,8 @@ int intel_histogram_init(struct intel_crtc *intel_crtc)
> histogram->crtc = intel_crtc;
> histogram->can_enable = false;
>
> + INIT_DEFERRABLE_WORK(&histogram->work,
> + intel_histogram_handle_int_work);
> +
> return 0;
> }
> diff --git a/drivers/gpu/drm/i915/display/intel_histogram.h
> b/drivers/gpu/drm/i915/display/intel_histogram.h
> index 9d66724f9c53..14f2425e3038 100644
> --- a/drivers/gpu/drm/i915/display/intel_histogram.h
> +++ b/drivers/gpu/drm/i915/display/intel_histogram.h
> @@ -9,6 +9,8 @@
> #include <linux/types.h>
>
> struct intel_crtc;
> +struct intel_display;
> +enum pipe;
>
> #define HISTOGRAM_BIN_COUNT 32
> #define HISTOGRAM_IET_LENGTH 33
> @@ -27,6 +29,7 @@ enum intel_global_hist_lut { };
>
> int intel_histogram_atomic_check(struct intel_crtc *intel_crtc);
> +void intel_histogram_irq_handler(struct intel_display *display, enum
> +pipe pipe);
> int intel_histogram_update(struct intel_crtc *intel_crtc, bool enable); int
> intel_histogram_set_iet_lut(struct intel_crtc *intel_crtc, u32 *data); int
> intel_histogram_init(struct intel_crtc *intel_crtc); diff --git
> a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index
> 7396fc630e29..7e062d6c8901 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -1643,7 +1643,7 @@
> #define PIPE_HOTPLUG_INTERRUPT_ENABLE (1UL << 26)
> #define PIPE_VSYNC_INTERRUPT_ENABLE (1UL << 25)
> #define PIPE_DISPLAY_LINE_COMPARE_ENABLE (1UL << 24)
> -#define PIPE_DPST_EVENT_ENABLE (1UL << 23)
> +#define PIPE_HISTOGRAM_EVENT_ENABLE (1UL << 23)
> #define SPRITE0_FLIP_DONE_INT_EN_VLV (1UL << 22)
> #define PIPE_LEGACY_BLC_EVENT_ENABLE (1UL << 22)
> #define PIPE_ODD_FIELD_INTERRUPT_ENABLE (1UL << 21)
> @@ -1666,7 +1666,7 @@
> #define PIPE_HOTPLUG_INTERRUPT_STATUS (1UL << 10)
> #define PIPE_VSYNC_INTERRUPT_STATUS (1UL << 9)
> #define PIPE_DISPLAY_LINE_COMPARE_STATUS (1UL << 8)
> -#define PIPE_DPST_EVENT_STATUS (1UL << 7)
> +#define PIPE_HISTOGRAM_EVENT_STATUS (1UL << 7)
> #define PIPE_A_PSR_STATUS_VLV (1UL << 6)
> #define PIPE_LEGACY_BLC_EVENT_STATUS (1UL << 6)
> #define PIPE_ODD_FIELD_INTERRUPT_STATUS (1UL << 5)
> @@ -2505,6 +2505,7 @@
> #define GEN12_DSB_1_INT REG_BIT(14) /* tgl+ */
> #define GEN12_DSB_0_INT REG_BIT(13) /* tgl+ */
> #define GEN12_DSB_INT(dsb_id) REG_BIT(13 + (dsb_id))
> +#define GEN9_PIPE_HISTOGRAM_EVENT REG_BIT(12) /* skl+ */
> #define GEN9_PIPE_CURSOR_FAULT REG_BIT(11) /* skl+ */
> #define GEN9_PIPE_PLANE4_FAULT REG_BIT(10) /* skl+ */
> #define GEN8_PIPE_CURSOR_FAULT REG_BIT(10) /* bdw */
> --
> 2.25.1
