wifi: iwlwifi: Force SCU_ACTIVE for specific platforms

Firmware 0x2F7 assert observed in Dell platforms when using GL HW.
This issue is mitigated by setting SCU_FORCE_ACTIVE during platform
low power states.

Driver shall indicate firmware to force SCU active by setting bit 29
in context info prph scratch control flags.
This mitigation is limited to Dell platforms with GL HW only.

Signed-off-by: Daniel Gabay <[email protected]>
Reviewed-by: Ofer Kimelman <[email protected]>
Signed-off-by: Miri Korenblit <[email protected]>
Link: https://msgid.link/20240506095953.3d0c56c2bb1a.I97d9da402890d2085b5698666cceffc417b6b6df@changeid
Signed-off-by: Johannes Berg <[email protected]>

Author: gabayd

drivers/net/wireless/intel/iwlwifi/iwl-context-info-gen3.h

@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
 /*
- * Copyright (C) 2018, 2020-2023 Intel Corporation
+ * Copyright (C) 2018, 2020-2024 Intel Corporation
  */
 #ifndef __iwl_context_info_file_gen3_h__
 #define __iwl_context_info_file_gen3_h__
@@ -56,6 +56,8 @@ enum iwl_prph_scratch_mtr_format {
  * @IWL_PRPH_SCRATCH_RB_SIZE_EXT_8K: 8kB RB size
  * @IWL_PRPH_SCRATCH_RB_SIZE_EXT_12K: 12kB RB size
  * @IWL_PRPH_SCRATCH_RB_SIZE_EXT_16K: 16kB RB size
+ * @IWL_PRPH_SCRATCH_SCU_FORCE_ACTIVE: Indicate fw to set SCU_FORCE_ACTIVE
+ *	upon reset.
  */
 enum iwl_prph_scratch_flags {
 	IWL_PRPH_SCRATCH_IMR_DEBUG_EN		= BIT(1),
@@ -71,6 +73,7 @@ enum iwl_prph_scratch_flags {
 	IWL_PRPH_SCRATCH_RB_SIZE_EXT_8K		= 8 << 20,
 	IWL_PRPH_SCRATCH_RB_SIZE_EXT_12K	= 9 << 20,
 	IWL_PRPH_SCRATCH_RB_SIZE_EXT_16K	= 10 << 20,
+	IWL_PRPH_SCRATCH_SCU_FORCE_ACTIVE	= BIT(29),
 };
 
 /*

drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info-gen3.c

@@ -1,13 +1,34 @@
 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
 /*
- * Copyright (C) 2018-2023 Intel Corporation
+ * Copyright (C) 2018-2024 Intel Corporation
  */
+#include <linux/dmi.h>
 #include "iwl-trans.h"
 #include "iwl-fh.h"
 #include "iwl-context-info-gen3.h"
 #include "internal.h"
 #include "iwl-prph.h"
 
+static const struct dmi_system_id dmi_force_scu_active_approved_list[] = {
+	{ .ident = "DELL",
+	  .matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+		},
+	},
+	{ .ident = "DELL",
+	  .matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Alienware"),
+		},
+	},
+	/* keep last */
+	{}
+};
+
+static bool iwl_is_force_scu_active_approved(void)
+{
+	return !!dmi_check_system(dmi_force_scu_active_approved_list);
+}
+
 static void
 iwl_pcie_ctxt_info_dbg_enable(struct iwl_trans *trans,
 			      struct iwl_prph_scratch_hwm_cfg *dbg_cfg,
@@ -128,6 +149,14 @@ int iwl_pcie_ctxt_info_gen3_init(struct iwl_trans *trans,
 	if (trans->trans_cfg->imr_enabled)
 		control_flags |= IWL_PRPH_SCRATCH_IMR_DEBUG_EN;
 
+	if (CSR_HW_REV_TYPE(trans->hw_rev) == IWL_CFG_MAC_TYPE_GL &&
+	    iwl_is_force_scu_active_approved()) {
+		control_flags |= IWL_PRPH_SCRATCH_SCU_FORCE_ACTIVE;
+		IWL_DEBUG_FW(trans,
+			     "Context Info: Set SCU_FORCE_ACTIVE (0x%x) in control_flags\n",
+			     IWL_PRPH_SCRATCH_SCU_FORCE_ACTIVE);
+	}
+
 	/* initialize RX default queue */
 	prph_sc_ctrl->rbd_cfg.free_rbd_addr =
 		cpu_to_le64(trans_pcie->rxq->bd_dma);