From 438f3d13da5e0714f1add1652865b864a2c36eb7 Mon Sep 17 00:00:00 2001
From: Stanislaw Gruszka <sgruszka@redhat.com>
Date: Mon, 15 May 2017 11:28:26 +0200
Subject: [PATCH] iwlegacy: warn when enabling power save
Git-commit: 438f3d13da5e0714f1add1652865b864a2c36eb7
Patch-mainline: v4.13-rc1
References: FATE#326294

iwlegacy firmware can crash when power save is configured. PS was
allowed in "dbdac2b iwlegacy: properly enable power saving" with belive
that user who enable PS is aware of that and can relate firmware crahes
with PS. However some distributions seems to enable PS without user
intervention, so warn about that.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/intel/iwlegacy/common.c | 2 ++
 drivers/net/wireless/intel/iwlegacy/common.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/drivers/net/wireless/intel/iwlegacy/common.c b/drivers/net/wireless/intel/iwlegacy/common.c
index 140b6ea8f7cc..8d5acda92a9b 100644
--- a/drivers/net/wireless/intel/iwlegacy/common.c
+++ b/drivers/net/wireless/intel/iwlegacy/common.c
@@ -5147,6 +5147,8 @@ il_mac_config(struct ieee80211_hw *hw, u32 changed)
 
 	if (changed & (IEEE80211_CONF_CHANGE_PS | IEEE80211_CONF_CHANGE_IDLE)) {
 		il->power_data.ps_disabled = !(conf->flags & IEEE80211_CONF_PS);
+		if (!il->power_data.ps_disabled)
+			IL_WARN_ONCE("Enabling power save might cause firmware crashes\n");
 		ret = il_power_update_mode(il, false);
 		if (ret)
 			D_MAC80211("Error setting sleep level\n");
diff --git a/drivers/net/wireless/intel/iwlegacy/common.h b/drivers/net/wireless/intel/iwlegacy/common.h
index 3bba521d2cd9..18c60c92e3a3 100644
--- a/drivers/net/wireless/intel/iwlegacy/common.h
+++ b/drivers/net/wireless/intel/iwlegacy/common.h
@@ -45,6 +45,7 @@ struct il_tx_queue;
 
 #define IL_ERR(f, a...) dev_err(&il->pci_dev->dev, f, ## a)
 #define IL_WARN(f, a...) dev_warn(&il->pci_dev->dev, f, ## a)
+#define IL_WARN_ONCE(f, a...) dev_warn_once(&il->pci_dev->dev, f, ## a)
 #define IL_INFO(f, a...) dev_info(&il->pci_dev->dev, f, ## a)
 
 #define RX_QUEUE_SIZE                         256
-- 
2.19.2