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From e234ca17f2d5ce23606fceef2df6c02f8555547e Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@redhat.com>
Date: Wed, 11 Jan 2012 13:35:33 -0500
Subject: [PATCH] rtl8192cu: Fix WARNING on suspend/resume

A recent LKML thread (http://lkml.indiana.edu/hypermail/linux/kernel/1112.3/00965.html)
discusses warnings that occur during a suspend/resume cycle. The driver
attempts to read the firmware file before userspace is ready, leading to the
following warning:

WARNING: at drivers/base/firmware_class.c:537 _request_firmware+0x3f6/0x420()

For rtl8192cu, the problem is fixed by storing the firmware in a global buffer
rather than one allocated per device. The usage count is increased when
suspending and decreased when resuming. This way, the firmware is retained
through a suspend/resume cycle, and does not have to be reread.

This patch should fix the bug reported in
https://bugzilla.redhat.com/show_bug.cgi?id=771002.

Note: This patch also touches rtl8192ce as the "firmware" loaded message
is now printed in the wrong place.

Reported-by: Mohammed Arafa <bugzilla@xxxxxxxxxxxx>
Reported-by: Dave Jones <davej@xxxxxxxxxx>
Signed-off-by: Larry Finger <Larry.Finger@xxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Stable <stable@xxxxxxxxxxxxxxx>

Backported to Fedora 3.1.x.
---
 drivers/net/wireless/rtlwifi/rtl8192c/fw_common.c |    1 -
 drivers/net/wireless/rtlwifi/rtl8192ce/sw.c       |    1 +
 drivers/net/wireless/rtlwifi/rtl8192cu/sw.c       |   58 +++++++++++++++++----
 3 files changed, 49 insertions(+), 11 deletions(-)

diff --git a/drivers/net/wireless/rtlwifi/rtl8192c/fw_common.c b/drivers/net/wireless/rtlwifi/rtl8192c/fw_common.c
index 49a064b..e3c4ac7 100644
--- a/drivers/net/wireless/rtlwifi/rtl8192c/fw_common.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192c/fw_common.c
@@ -226,7 +226,6 @@ int rtl92c_download_fw(struct ieee80211_hw *hw)
 	u32 fwsize;
 	enum version_8192c version = rtlhal->version;
 
-	pr_info("Loading firmware file %s\n", rtlpriv->cfg->fw_name);
 	if (!rtlhal->pfirmware)
 		return 1;
 
diff --git a/drivers/net/wireless/rtlwifi/rtl8192ce/sw.c b/drivers/net/wireless/rtlwifi/rtl8192ce/sw.c
index 373dc78..9c3a8f1 100644
--- a/drivers/net/wireless/rtlwifi/rtl8192ce/sw.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192ce/sw.c
@@ -171,6 +171,7 @@ int rtl92c_init_sw_vars(struct ieee80211_hw *hw)
 	memcpy(rtlpriv->rtlhal.pfirmware, firmware->data, firmware->size);
 	rtlpriv->rtlhal.fwsize = firmware->size;
 	release_firmware(firmware);
+	pr_info("rtl8192ce: Loaded firmware file %s\n", rtlpriv->cfg->fw_name);
 
 	return 0;
 }
diff --git a/drivers/net/wireless/rtlwifi/rtl8192cu/sw.c b/drivers/net/wireless/rtlwifi/rtl8192cu/sw.c
index ef63c0d..f4230dd 100644
--- a/drivers/net/wireless/rtlwifi/rtl8192cu/sw.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192cu/sw.c
@@ -42,6 +42,9 @@
 #include "led.h"
 #include "hw.h"
 #include <linux/vmalloc.h>
+#include <linux/atomic.h>
+#include <linux/types.h>
+
 
 MODULE_AUTHOR("Georgia		<georgia@realtek.com>");
 MODULE_AUTHOR("Ziv Huang	<ziv_huang@realtek.com>");
@@ -50,6 +53,10 @@ MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Realtek 8192C/8188C 802.11n USB wireless");
 MODULE_FIRMWARE("rtlwifi/rtl8192cufw.bin");
 
+static char *rtl8192cu_firmware;		/* pointer to firmware */
+static int firmware_size;
+static atomic_t usage_count;
+
 static int rtl92cu_init_sw_vars(struct ieee80211_hw *hw)
 {
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
@@ -60,12 +67,21 @@ static int rtl92cu_init_sw_vars(struct ieee80211_hw *hw)
 	rtlpriv->dm.dm_flag = 0;
 	rtlpriv->dm.disable_framebursting = 0;
 	rtlpriv->dm.thermalvalue = 0;
-	rtlpriv->rtlhal.pfirmware = vmalloc(0x4000);
-	if (!rtlpriv->rtlhal.pfirmware) {
+
+	if (rtl8192cu_firmware) {
+		/* firmware already loaded - true for suspend/resume
+		 * and multiple instances of the device */
+		rtlpriv->rtlhal.pfirmware = rtl8192cu_firmware;
+		rtlpriv->rtlhal.fwsize = firmware_size;
+		return 0;
+	}
+	rtl8192cu_firmware = vzalloc(0x4000);
+	if (!rtl8192cu_firmware) {
 		RT_TRACE(rtlpriv, COMP_ERR, DBG_EMERG,
 			 ("Can't alloc buffer for fw.\n"));
 		return 1;
 	}
+
 	/* request fw */
 	err = request_firmware(&firmware, rtlpriv->cfg->fw_name,
 			rtlpriv->io.dev);
@@ -80,9 +96,14 @@ static int rtl92cu_init_sw_vars(struct ieee80211_hw *hw)
 		release_firmware(firmware);
 		return 1;
 	}
-	memcpy(rtlpriv->rtlhal.pfirmware, firmware->data, firmware->size);
+	pr_info("rtl8192cu: Loaded firmware from file %s\n",
+		rtlpriv->cfg->fw_name);
+	memcpy(rtl8192cu_firmware, firmware->data, firmware->size);
+	firmware_size = firmware->size;
 	rtlpriv->rtlhal.fwsize = firmware->size;
+	rtlpriv->rtlhal.pfirmware = rtl8192cu_firmware;
 	release_firmware(firmware);
+	atomic_inc(&usage_count);
 
 	return 0;
 }
@@ -91,12 +112,30 @@ static void rtl92cu_deinit_sw_vars(struct ieee80211_hw *hw)
 {
 	struct rtl_priv *rtlpriv = rtl_priv(hw);
 
-	if (rtlpriv->rtlhal.pfirmware) {
-		vfree(rtlpriv->rtlhal.pfirmware);
+	atomic_dec(&usage_count);
+	if (!atomic_read(&usage_count) && rtlpriv->rtlhal.pfirmware) {
+		vfree(rtl8192cu_firmware);
+		rtl8192cu_firmware = NULL;
 		rtlpriv->rtlhal.pfirmware = NULL;
 	}
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int rtl8192cu_usb_suspend(struct usb_interface *pusb_intf,
+				 pm_message_t message)
+{
+	/* Increase usage_count to Save loaded fw across suspend/resume */
+	atomic_inc(&usage_count);
+	return 0;
+}
+
+static int rtl8192cu_usb_resume(struct usb_interface *pusb_intf)
+{
+	atomic_dec(&usage_count);	/* after resume, decrease usage count */
+	return 0;
+}
+#endif
+
 static struct rtl_hal_ops rtl8192cu_hal_ops = {
 	.init_sw_vars = rtl92cu_init_sw_vars,
 	.deinit_sw_vars = rtl92cu_deinit_sw_vars,
@@ -338,11 +377,10 @@ static struct usb_driver rtl8192cu_driver = {
 	.disconnect = rtl_usb_disconnect,
 	.id_table = rtl8192c_usb_ids,
 
-#ifdef CONFIG_PM
-	/* .suspend = rtl_usb_suspend, */
-	/* .resume = rtl_usb_resume, */
-	/* .reset_resume = rtl8192c_resume, */
-#endif /* CONFIG_PM */
+#ifdef CONFIG_PM_SLEEP
+	.suspend = rtl8192cu_usb_suspend,
+	.resume = rtl8192cu_usb_resume,
+#endif /* CONFIG_PM_SLEEP */
 #ifdef CONFIG_AUTOSUSPEND
 	.supports_autosuspend = 1,
 #endif
-- 
1.7.7.5