From 6bd8bd2f5e162408fc49ff122bfcc05a2c91e4da Mon Sep 17 00:00:00 2001
From: jsg <jsg@openbsd.org>
Date: Tue, 20 Jun 2023 02:35:50 +0000
Subject: [PATCH] drm/amd/pm: conditionally disable pcie lane switching for
 some sienna_cichlid SKUs

From Evan Quan
416ba40ff3c4ecafbed19029c9e9884a7fee3da5 in linux-6.1.y/6.1.34
38e4ced804796c5725e2a52ec3601951552c4a97 in mainline linux
---
 .../amd/pm/swsmu/smu11/sienna_cichlid_ppt.c   | 94 +++++++++++++++----
 1 file changed, 76 insertions(+), 18 deletions(-)

diff --git a/sys/dev/pci/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c b/sys/dev/pci/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
index 033e75b2d0a..f106763952a 100644
--- a/sys/dev/pci/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
+++ b/sys/dev/pci/drm/amd/pm/swsmu/smu11/sienna_cichlid_ppt.c
@@ -2067,33 +2067,96 @@ static int sienna_cichlid_display_disable_memory_clock_switch(struct smu_context
 	return ret;
 }
 
+static void sienna_cichlid_get_override_pcie_settings(struct smu_context *smu,
+						      uint32_t *gen_speed_override,
+						      uint32_t *lane_width_override)
+{
+	struct amdgpu_device *adev = smu->adev;
+
+	*gen_speed_override = 0xff;
+	*lane_width_override = 0xff;
+
+	switch (adev->pdev->device) {
+	case 0x73A0:
+	case 0x73A1:
+	case 0x73A2:
+	case 0x73A3:
+	case 0x73AB:
+	case 0x73AE:
+		/* Bit 7:0: PCIE lane width, 1 to 7 corresponds is x1 to x32 */
+		*lane_width_override = 6;
+		break;
+	case 0x73E0:
+	case 0x73E1:
+	case 0x73E3:
+		*lane_width_override = 4;
+		break;
+	case 0x7420:
+	case 0x7421:
+	case 0x7422:
+	case 0x7423:
+	case 0x7424:
+		*lane_width_override = 3;
+		break;
+	default:
+		break;
+	}
+}
+
+#ifndef MAX
+#define MAX(a, b)	((a) > (b) ? (a) : (b))
+#endif
+
 static int sienna_cichlid_update_pcie_parameters(struct smu_context *smu,
 					 uint32_t pcie_gen_cap,
 					 uint32_t pcie_width_cap)
 {
 	struct smu_11_0_dpm_context *dpm_context = smu->smu_dpm.dpm_context;
-
-	uint32_t smu_pcie_arg;
+	struct smu_11_0_pcie_table *pcie_table = &dpm_context->dpm_tables.pcie_table;
+	uint32_t gen_speed_override, lane_width_override;
 	uint8_t *table_member1, *table_member2;
+	uint32_t min_gen_speed, max_gen_speed;
+	uint32_t min_lane_width, max_lane_width;
+	uint32_t smu_pcie_arg;
 	int ret, i;
 
 	GET_PPTABLE_MEMBER(PcieGenSpeed, &table_member1);
 	GET_PPTABLE_MEMBER(PcieLaneCount, &table_member2);
 
-	/* lclk dpm table setup */
-	for (i = 0; i < MAX_PCIE_CONF; i++) {
-		dpm_context->dpm_tables.pcie_table.pcie_gen[i] = table_member1[i];
-		dpm_context->dpm_tables.pcie_table.pcie_lane[i] = table_member2[i];
+	sienna_cichlid_get_override_pcie_settings(smu,
+						  &gen_speed_override,
+						  &lane_width_override);
+
+	/* PCIE gen speed override */
+	if (gen_speed_override != 0xff) {
+		min_gen_speed = MIN(pcie_gen_cap, gen_speed_override);
+		max_gen_speed = MIN(pcie_gen_cap, gen_speed_override);
+	} else {
+		min_gen_speed = MAX(0, table_member1[0]);
+		max_gen_speed = MIN(pcie_gen_cap, table_member1[1]);
+		min_gen_speed = min_gen_speed > max_gen_speed ?
+				max_gen_speed : min_gen_speed;
 	}
+	pcie_table->pcie_gen[0] = min_gen_speed;
+	pcie_table->pcie_gen[1] = max_gen_speed;
+
+	/* PCIE lane width override */
+	if (lane_width_override != 0xff) {
+		min_lane_width = MIN(pcie_width_cap, lane_width_override);
+		max_lane_width = MIN(pcie_width_cap, lane_width_override);
+	} else {
+		min_lane_width = MAX(1, table_member2[0]);
+		max_lane_width = MIN(pcie_width_cap, table_member2[1]);
+		min_lane_width = min_lane_width > max_lane_width ?
+				 max_lane_width : min_lane_width;
+	}
+	pcie_table->pcie_lane[0] = min_lane_width;
+	pcie_table->pcie_lane[1] = max_lane_width;
 
 	for (i = 0; i < NUM_LINK_LEVELS; i++) {
-		smu_pcie_arg = (i << 16) |
-			((table_member1[i] <= pcie_gen_cap) ?
-			 (table_member1[i] << 8) :
-			 (pcie_gen_cap << 8)) |
-			((table_member2[i] <= pcie_width_cap) ?
-			 table_member2[i] :
-			 pcie_width_cap);
+		smu_pcie_arg = (i << 16 |
+				pcie_table->pcie_gen[i] << 8 |
+				pcie_table->pcie_lane[i]);
 
 		ret = smu_cmn_send_smc_msg_with_param(smu,
 				SMU_MSG_OverridePcieParameters,
@@ -2101,11 +2164,6 @@ static int sienna_cichlid_update_pcie_parameters(struct smu_context *smu,
 				NULL);
 		if (ret)
 			return ret;
-
-		if (table_member1[i] > pcie_gen_cap)
-			dpm_context->dpm_tables.pcie_table.pcie_gen[i] = pcie_gen_cap;
-		if (table_member2[i] > pcie_width_cap)
-			dpm_context->dpm_tables.pcie_table.pcie_lane[i] = pcie_width_cap;
 	}
 
 	return 0;
-- 
2.20.1