From 7e030d6dff713250c7dcfb543cad2addaf479b0e Mon Sep 17 00:00:00 2001
From: Corey Minyard <cminyard@mvista.com>
Date: Fri, 8 Sep 2017 14:05:58 -0500
Subject: [PATCH] ipmi: Prefer ACPI system interfaces over SMBIOS ones
Git-commit: 7e030d6dff713250c7dcfb543cad2addaf479b0e
Patch-mainline: v4.15-rc1
References: bsc#1070006

The recent changes to add SMBIOS (DMI) IPMI interfaces as platform
devices caused DMI to be selected before ACPI, causing ACPI type
of operations to not work.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/char/ipmi/ipmi_si_intf.c |   33 +++++++++++++++++++++++----------
 1 file changed, 23 insertions(+), 10 deletions(-)

--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -3445,7 +3445,7 @@ static inline void wait_for_timer_and_th
 		del_timer_sync(&smi_info->si_timer);
 }
 
-static int is_new_interface(struct smi_info *info)
+static struct smi_info *find_dup_si(struct smi_info *info)
 {
 	struct smi_info *e;
 
@@ -3460,24 +3460,36 @@ static int is_new_interface(struct smi_i
 			 */
 			if (info->slave_addr && !e->slave_addr)
 				e->slave_addr = info->slave_addr;
-			return 0;
+			return e;
 		}
 	}
 
-	return 1;
+	return NULL;
 }
 
 static int add_smi(struct smi_info *new_smi)
 {
 	int rv = 0;
+	struct smi_info *dup;
 
 	mutex_lock(&smi_infos_lock);
-	if (!is_new_interface(new_smi)) {
-		pr_info(PFX "%s-specified %s state machine: duplicate\n",
-			ipmi_addr_src_to_str(new_smi->addr_source),
-			si_to_str[new_smi->si_type]);
-		rv = -EBUSY;
-		goto out_err;
+	dup = find_dup_si(new_smi);
+	if (dup) {
+		if (new_smi->addr_source == SI_ACPI &&
+		    dup->addr_source == SI_SMBIOS) {
+			/* We prefer ACPI over SMBIOS. */
+			dev_info(dup->dev,
+				 "Removing SMBIOS-specified %s state machine in favor of ACPI\n",
+				 si_to_str[new_smi->si_type]);
+			cleanup_one_si(dup);
+		} else {
+			dev_info(new_smi->dev,
+				 "%s-specified %s state machine: duplicate\n",
+				 ipmi_addr_src_to_str(new_smi->addr_source),
+				 si_to_str[new_smi->si_type]);
+			rv = -EBUSY;
+			goto out_err;
+		}
 	}
 
 	pr_info(PFX "Adding %s-specified %s state machine\n",
@@ -3891,7 +3903,8 @@ static void cleanup_one_si(struct smi_in
 		poll(to_clean);
 		schedule_timeout_uninterruptible(1);
 	}
-	disable_si_irq(to_clean, false);
+	if (to_clean->handlers)
+		disable_si_irq(to_clean, false);
 	while (to_clean->curr_msg || (to_clean->si_state != SI_NORMAL)) {
 		poll(to_clean);
 		schedule_timeout_uninterruptible(1);