Mesa (master): radv: Use a lower max offchip buffer count.

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Module: Mesa
Branch: master
Commit: ab64891f4c6ebab214b84debb1254b134d6c7c64
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=ab64891f4c6ebab214b84debb1254b134d6c7c64

Author: Bas Nieuwenhuizen <bas at basnieuwenhuizen.nl>
Date:   Mon Sep  3 02:30:48 2018 +0200

radv: Use a lower max offchip buffer count.

No clue what gets fixed by this but both radeonsi and amdvlk do it.

CC: <mesa-stable at lists.freedesktop.org>
Reviewed-by: Dave Airlie <airlied at redhat.com>
Reviewed-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>

---

 src/amd/vulkan/radv_device.c | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/src/amd/vulkan/radv_device.c b/src/amd/vulkan/radv_device.c
index c300c88468..53f99a8cec 100644
--- a/src/amd/vulkan/radv_device.c
+++ b/src/amd/vulkan/radv_device.c
@@ -1901,10 +1901,30 @@ radv_get_hs_offchip_param(struct radv_device *device, uint32_t *max_offchip_buff
 		device->physical_device->rad_info.family != CHIP_CARRIZO &&
 		device->physical_device->rad_info.family != CHIP_STONEY;
 	unsigned max_offchip_buffers_per_se = double_offchip_buffers ? 128 : 64;
-	unsigned max_offchip_buffers = max_offchip_buffers_per_se *
-		device->physical_device->rad_info.max_se;
+	unsigned max_offchip_buffers;
 	unsigned offchip_granularity;
 	unsigned hs_offchip_param;
+
+	/*
+	 * Per RadeonSI:
+	 * This must be one less than the maximum number due to a hw limitation.
+         * Various hardware bugs in SI, CIK, and GFX9 need this.
+	 *
+	 * Per AMDVLK:
+	 * Vega10 should limit max_offchip_buffers to 508 (4 * 127).
+	 * Gfx7 should limit max_offchip_buffers to 508
+	 * Gfx6 should limit max_offchip_buffers to 126 (2 * 63)
+	 *
+	 * Follow AMDVLK here.
+	 */
+	if (device->physical_device->rad_info.family == CHIP_VEGA10 ||
+	    device->physical_device->rad_info.chip_class == CIK ||
+	    device->physical_device->rad_info.chip_class == SI)
+		--max_offchip_buffers_per_se;
+
+	max_offchip_buffers = max_offchip_buffers_per_se *
+		device->physical_device->rad_info.max_se;
+
 	switch (device->tess_offchip_block_dw_size) {
 	default:
 		assert(0);