drm/etnaviv: Add module parameter to force PPU flop reset

v2: Check for feature PIPE_3D when forcing PPU flop reset (Lucas)

v3: - drop use of ppu_flop_reset enum (Christian Gmeiner)
    - don't initialize module parameter to zero (checkpatch)
    - avoid multi-line string in warning message (checkpatch)

Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Christian Gmeiner <cgmeiner@igalia.com>
Tested-by: Marek Vasut <marek.vasut@mailbox.org> # STM32MP255C DHCOS DHSBC
Link: https://patch.msgid.link/20251119164624.9297-6-gert.wollny@collabora.com
Signed-off-by: Christian Gmeiner <cgmeiner@igalia.com>

Author: gerddie

drivers/gpu/drm/etnaviv/etnaviv_flop_reset.c

@@ -15,6 +15,9 @@
 
 #include "etnaviv_flop_reset.h"
 
+static int etnaviv_force_flop_reset;
+module_param_named(force_flop_reset, etnaviv_force_flop_reset, int, 0);
+
 #define PPU_IMAGE_STRIDE 64
 #define PPU_IMAGE_XSIZE 64
 #define PPU_IMAGE_YSIZE 6
@@ -150,6 +153,19 @@ bool etnaviv_flop_reset_ppu_require(const struct etnaviv_chip_identity *chip_id)
 			return true;
 	}
 
+	if (etnaviv_force_flop_reset) {
+		if (!(chip_id->features & chipFeatures_PIPE_3D)) {
+			pr_warn("Etnaviv: model: 0x%04x, revision: 0x%04x does not support PIPE_3D\n",
+				chip_id->model, chip_id->revision);
+			pr_warn("Request to force PPU flop reset ignored.\n");
+			return false;
+		}
+
+		pr_info("Force PPU flop reset for model: 0x%04x, revision: 0x%04x\n",
+			chip_id->model, chip_id->revision);
+		return true;
+	}
+
 	return false;
 }