drm/vc4: hvs: Add debugfs node that dumps the current display lists

This allows easy analysis of display lists when debugging.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-8-maxime@cerno.tech
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index 2a58fc4..5fdfc01 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -94,6 +94,46 @@ static int vc4_hvs_debugfs_underrun(struct seq_file *m, void *data)
        return 0;
 }
 
+static int vc4_hvs_debugfs_dlist(struct seq_file *m, void *data)
+{
+       struct drm_info_node *node = m->private;
+       struct drm_device *dev = node->minor->dev;
+       struct vc4_dev *vc4 = to_vc4_dev(dev);
+       struct vc4_hvs *hvs = vc4->hvs;
+       struct drm_printer p = drm_seq_file_printer(m);
+       unsigned int next_entry_start = 0;
+       unsigned int i, j;
+       u32 dlist_word, dispstat;
+
+       for (i = 0; i < SCALER_CHANNELS_COUNT; i++) {
+               dispstat = VC4_GET_FIELD(HVS_READ(SCALER_DISPSTATX(i)),
+                                        SCALER_DISPSTATX_MODE);
+               if (dispstat == SCALER_DISPSTATX_MODE_DISABLED ||
+                   dispstat == SCALER_DISPSTATX_MODE_EOF) {
+                       drm_printf(&p, "HVS chan %u disabled\n", i);
+                       continue;
+               }
+
+               drm_printf(&p, "HVS chan %u:\n", i);
+
+               for (j = HVS_READ(SCALER_DISPLISTX(i)); j < 256; j++) {
+                       dlist_word = readl((u32 __iomem *)vc4->hvs->dlist + j);
+                       drm_printf(&p, "dlist: %02d: 0x%08x\n", j,
+                                  dlist_word);
+                       if (!next_entry_start ||
+                           next_entry_start == j) {
+                               if (dlist_word & SCALER_CTL0_END)
+                                       break;
+                               next_entry_start = j +
+                                       VC4_GET_FIELD(dlist_word,
+                                                     SCALER_CTL0_SIZE);
+                       }
+               }
+       }
+
+       return 0;
+}
+
 /* The filter kernel is composed of dwords each containing 3 9-bit
  * signed integers packed next to each other.
  */
@@ -734,6 +774,8 @@ static int vc4_hvs_bind(struct device *dev, struct device *master, void *data)
        vc4_debugfs_add_regset32(drm, "hvs_regs", &hvs->regset);
        vc4_debugfs_add_file(drm, "hvs_underrun", vc4_hvs_debugfs_underrun,
                             NULL);
+       vc4_debugfs_add_file(drm, "hvs_dlists", vc4_hvs_debugfs_dlist,
+                            NULL);
 
        return 0;
 }