@@ -359,6 +359,39 @@ bool intel_set_pch_fifo_underrun_reporting(struct drm_i915_private *dev_priv,
return old;
}
+static u32
+underrun_pipestat_mask(struct drm_i915_private *dev_priv)
+{
+ u32 mask = PIPE_FIFO_UNDERRUN_STATUS;
+
+ if (DISPLAY_VER(dev_priv) >= 13)
+ mask |= PIPE_STAT_SOFT_UNDERRUN_XELPD |
+ PIPE_STAT_HARD_UNDERRUN_XELPD |
+ PIPE_STAT_PORT_UNDERRUN_XELPD;
+
+ return mask;
+}
+
+static const char *
+pipe_underrun_reason(u32 pipestat_underruns)
+{
+ if (pipestat_underruns & PIPE_STAT_SOFT_UNDERRUN_XELPD)
+ /*
+ * Hardware used replacement/interpolated pixels at
+ * underrun locations.
+ */
+ return "soft";
+ else if (pipestat_underruns & PIPE_STAT_HARD_UNDERRUN_XELPD)
+ /*
+ * Hardware used previous pixel value at underrun
+ * locations.
+ */
+ return "hard";
+ else
+ /* Old platform or no extra soft/hard bit set */
+ return "FIFO";
+}
+
/**
* intel_cpu_fifo_underrun_irq_handler - handle CPU fifo underrun interrupt
* @dev_priv: i915 device instance
@@ -372,6 +405,7 @@ void intel_cpu_fifo_underrun_irq_handler(struct drm_i915_private *dev_priv,
enum pipe pipe)
{
struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
+ u32 underruns = 0;
/* We may be called too early in init, thanks BIOS! */
if (crtc == NULL)
@@ -382,10 +416,37 @@ void intel_cpu_fifo_underrun_irq_handler(struct drm_i915_private *dev_priv,
crtc->cpu_fifo_underrun_disabled)
return;
+ /*
+ * Starting with display version 11, the PIPE_STAT register records
+ * whether an underrun has happened, and on XELPD+, it will also record
+ * whether the underrun was soft/hard and whether it was triggered by
+ * the downstream port logic. We should clear these bits (which use
+ * write-1-to-clear logic) too.
+ *
+ * Note that although the IIR gives us the same underrun and soft/hard
+ * information, PIPE_STAT is the only place we can find out whether
+ * the underrun was caused by the downstream port.
+ */
+ if (DISPLAY_VER(dev_priv) >= 11) {
+ underruns = intel_uncore_read(&dev_priv->uncore,
+ ICL_PIPESTATUS(pipe)) &
+ underrun_pipestat_mask(dev_priv);
+ intel_uncore_write(&dev_priv->uncore, ICL_PIPESTATUS(pipe),
+ underruns);
+ }
+
if (intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, false)) {
trace_intel_cpu_fifo_underrun(dev_priv, pipe);
- drm_err(&dev_priv->drm, "CPU pipe %c FIFO underrun\n",
- pipe_name(pipe));
+
+ if (underruns & PIPE_STAT_PORT_UNDERRUN_XELPD)
+ /* Underrun was caused downstream from the pipes */
+ drm_err(&dev_priv->drm, "Port triggered a %s underrun on pipe %c\n",
+ pipe_underrun_reason(underruns),
+ pipe_name(pipe));
+ else
+ drm_err(&dev_priv->drm, "CPU pipe %c %s underrun\n",
+ pipe_name(pipe),
+ pipe_underrun_reason(underruns));
}
intel_fbc_handle_fifo_underrun_irq(dev_priv);
@@ -2424,6 +2424,18 @@ static u32 gen8_de_pipe_flip_done_mask(struct drm_i915_private *i915)
return GEN8_PIPE_PRIMARY_FLIP_DONE;
}
+static u32
+underrun_iir_mask(struct drm_i915_private *dev_priv)
+{
+ u32 mask = GEN8_PIPE_FIFO_UNDERRUN;
+
+ if (DISPLAY_VER(dev_priv) >= 13)
+ mask |= XELPD_PIPE_SOFT_UNDERRUN |
+ XELPD_PIPE_HARD_UNDERRUN;
+
+ return mask;
+}
+
static irqreturn_t
gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
{
@@ -2532,7 +2544,7 @@ gen8_de_irq_handler(struct drm_i915_private *dev_priv, u32 master_ctl)
if (iir & GEN8_PIPE_CDCLK_CRC_DONE)
hsw_pipe_crc_irq_handler(dev_priv, pipe);
- if (iir & GEN8_PIPE_FIFO_UNDERRUN)
+ if (iir & underrun_iir_mask(dev_priv))
intel_cpu_fifo_underrun_irq_handler(dev_priv, pipe);
fault_errors = iir & gen8_de_pipe_fault_mask(dev_priv);
@@ -6139,6 +6139,12 @@ enum {
#define SKL_BOTTOM_COLOR_CSC_ENABLE (1 << 30)
#define SKL_BOTTOM_COLOR(pipe) _MMIO_PIPE2(pipe, _SKL_BOTTOM_COLOR_A)
+#define _ICL_PIPE_A_STATUS 0x70058
+#define ICL_PIPESTATUS(pipe) _MMIO_PIPE2(pipe, _ICL_PIPE_A_STATUS)
+#define PIPE_STAT_SOFT_UNDERRUN_XELPD REG_BIT(28)
+#define PIPE_STAT_HARD_UNDERRUN_XELPD REG_BIT(27)
+#define PIPE_STAT_PORT_UNDERRUN_XELPD REG_BIT(26)
+
#define VLV_DPFLIPSTAT _MMIO(VLV_DISPLAY_BASE + 0x70028)
#define PIPEB_LINE_COMPARE_INT_EN (1 << 29)
#define PIPEB_HLINE_INT_EN (1 << 28)
@@ -7792,6 +7798,8 @@ enum {
#define GEN8_PIPE_FIFO_UNDERRUN (1 << 31)
#define GEN8_PIPE_CDCLK_CRC_ERROR (1 << 29)
#define GEN8_PIPE_CDCLK_CRC_DONE (1 << 28)
+#define XELPD_PIPE_SOFT_UNDERRUN (1 << 22)
+#define XELPD_PIPE_HARD_UNDERRUN (1 << 21)
#define GEN8_PIPE_CURSOR_FAULT (1 << 10)
#define GEN8_PIPE_SPRITE_FAULT (1 << 9)
#define GEN8_PIPE_PRIMARY_FAULT (1 << 8)
XE_LPD brings enhanced underrun recovery: the hardware can somewhat mitigate underruns by using an interpolated replacement pixel (soft underrun) or the previous pixel (hard underrun). Furthermore, underruns can now be caused downstream by the port, even if the pipe itself is operating properly. The interrupt register and PIPE_STATUS register give us extra bits to recognize hard/soft underruns and determine whether the underrun was caused by the port, so we'll use that information to print some more descriptive errors when underruns occur. v2: - Keep ICL's PIPE_STATUS defined separately from the old GMCH pipe status register. (Ville) - Only read/clear the PIPE_STATUS register on platforms with display ver >= 11. (Lucas) Bspec: 50335 Bspec: 50366 Cc: Lucas De Marchi <lucas.demarchi@intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Matt Roper <matthew.d.roper@intel.com> --- .../drm/i915/display/intel_fifo_underrun.c | 65 ++++++++++++++++++- drivers/gpu/drm/i915/i915_irq.c | 14 +++- drivers/gpu/drm/i915/i915_reg.h | 8 +++ 3 files changed, 84 insertions(+), 3 deletions(-)