diff --git a/drivers/staging/r8188eu/core/rtw_led.c b/drivers/staging/r8188eu/core/rtw_led.c
index 37c9766b4c64..ee90e52adc90 100644
--- a/drivers/staging/r8188eu/core/rtw_led.c
+++ b/drivers/staging/r8188eu/core/rtw_led.c
@@ -9,17 +9,9 @@
 /*		Callback function of LED BlinkTimer, */
 /*		it just schedules to corresponding BlinkWorkItem/led_blink_hdl */
 /*  */
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 void BlinkTimerCallback(struct timer_list *t)
-#else
-void BlinkTimerCallback(void *data)
-#endif
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	struct LED_871x *pLed = from_timer(pLed, t, BlinkTimer);
-#else
-	struct LED_871x *pLed = (struct LED_871x *)data;
-#endif
 	struct adapter *padapter = pLed->padapter;
 
 	if ((padapter->bSurpriseRemoved) || (padapter->bDriverStopped))
@@ -69,11 +61,7 @@ void InitLed871x(struct adapter *padapter, struct LED_871x *pLed, enum LED_PIN_8
 
 	ResetLedStatus(pLed);
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	timer_setup(&pLed->BlinkTimer, BlinkTimerCallback, 0);
-#else
-	_init_timer(&(pLed->BlinkTimer), padapter->pnetdev, BlinkTimerCallback, pLed);
-#endif
 	_init_workitem(&(pLed->BlinkWorkItem), BlinkWorkItemCallback, pLed);
 }
 
diff --git a/drivers/staging/r8188eu/core/rtw_p2p.c b/drivers/staging/r8188eu/core/rtw_p2p.c
index 0c97c42eb420..3ec988fad6ea 100644
--- a/drivers/staging/r8188eu/core/rtw_p2p.c
+++ b/drivers/staging/r8188eu/core/rtw_p2p.c
@@ -1728,17 +1728,9 @@ u8 p2p_ps_wk_cmd(struct adapter *padapter, u8 p2p_ps_state, u8 enqueue)
 	return res;
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 static void reset_ch_sitesurvey_timer_process(struct timer_list *t)
-#else
-static void reset_ch_sitesurvey_timer_process (void *FunctionContext)
-#endif
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	struct adapter *adapter = from_timer(adapter, t, pwrctrlpriv.pwr_state_check_timer);
-#else
-	struct adapter *adapter = (struct adapter *)FunctionContext;
-#endif
 	struct	wifidirect_info		*pwdinfo = &adapter->wdinfo;
 
 	if (rtw_p2p_chk_state(pwdinfo, P2P_STATE_NONE))
@@ -1750,17 +1742,9 @@ static void reset_ch_sitesurvey_timer_process (void *FunctionContext)
 	pwdinfo->rx_invitereq_info.scan_op_ch_only = 0;
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 static void reset_ch_sitesurvey_timer_process2 (struct timer_list *t)
-#else
-static void reset_ch_sitesurvey_timer_process2 (void *FunctionContext)
-#endif
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	struct adapter *adapter = from_timer(adapter, t, pwrctrlpriv.pwr_state_check_timer);
-#else
-	struct adapter *adapter = (struct adapter *)FunctionContext;
-#endif
 	struct	wifidirect_info		*pwdinfo = &adapter->wdinfo;
 
 	if (rtw_p2p_chk_state(pwdinfo, P2P_STATE_NONE))
@@ -1772,17 +1756,9 @@ static void reset_ch_sitesurvey_timer_process2 (void *FunctionContext)
 	pwdinfo->p2p_info.scan_op_ch_only = 0;
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 static void restore_p2p_state_timer_process(struct timer_list *t)
-#else
-static void restore_p2p_state_timer_process (void *FunctionContext)
-#endif
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	struct adapter *adapter = from_timer(adapter, t, wdinfo.restore_p2p_state_timer);
-#else
-	struct adapter *adapter = (struct adapter *)FunctionContext;
-#endif
 	struct	wifidirect_info		*pwdinfo = &adapter->wdinfo;
 
 	if (rtw_p2p_chk_state(pwdinfo, P2P_STATE_NONE))
@@ -1791,17 +1767,9 @@ static void restore_p2p_state_timer_process (void *FunctionContext)
 	p2p_protocol_wk_cmd(adapter, P2P_RESTORE_STATE_WK);
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 static void pre_tx_scan_timer_process(struct timer_list *t)
-#else
-static void pre_tx_scan_timer_process(void *FunctionContext)
-#endif
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	struct adapter *adapter = from_timer(adapter, t, wdinfo.pre_tx_scan_timer);
-#else
-	struct adapter *adapter = (struct adapter *)FunctionContext;
-#endif
 	struct	wifidirect_info *pwdinfo = &adapter->wdinfo;
 	struct mlme_priv *pmlmepriv = &adapter->mlmepriv;
 
@@ -1829,17 +1797,9 @@ static void pre_tx_scan_timer_process(void *FunctionContext)
 	spin_unlock_bh(&pmlmepriv->lock);
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 static void find_phase_timer_process(struct timer_list *t)
-#else
-static void find_phase_timer_process(void *FunctionContext)
-#endif
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	struct adapter *adapter = from_timer(adapter, t, wdinfo.find_phase_timer);
-#else
-	struct adapter *adapter = (struct adapter *)FunctionContext;
-#endif
 	struct	wifidirect_info		*pwdinfo = &adapter->wdinfo;
 
 	if (rtw_p2p_chk_state(pwdinfo, P2P_STATE_NONE))
@@ -1865,19 +1825,11 @@ void rtw_init_wifidirect_timers(struct adapter *padapter)
 {
 	struct wifidirect_info *pwdinfo = &padapter->wdinfo;
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	timer_setup(&pwdinfo->find_phase_timer, find_phase_timer_process, 0);
 	timer_setup(&pwdinfo->restore_p2p_state_timer, restore_p2p_state_timer_process, 0);
 	timer_setup(&pwdinfo->pre_tx_scan_timer, pre_tx_scan_timer_process, 0);
 	timer_setup(&pwdinfo->reset_ch_sitesurvey, reset_ch_sitesurvey_timer_process, 0);
 	timer_setup(&pwdinfo->reset_ch_sitesurvey2, reset_ch_sitesurvey_timer_process2, 0);
-#else
-	_init_timer(&pwdinfo->find_phase_timer, padapter->pnetdev, find_phase_timer_process, padapter);
-	_init_timer(&pwdinfo->restore_p2p_state_timer, padapter->pnetdev, restore_p2p_state_timer_process, padapter);
-	_init_timer(&pwdinfo->pre_tx_scan_timer, padapter->pnetdev, pre_tx_scan_timer_process, padapter);
-	_init_timer(&pwdinfo->reset_ch_sitesurvey, padapter->pnetdev, reset_ch_sitesurvey_timer_process, padapter);
-	_init_timer(&pwdinfo->reset_ch_sitesurvey2, padapter->pnetdev, reset_ch_sitesurvey_timer_process2, padapter);
-#endif
 }
 
 void rtw_init_wifidirect_addrs(struct adapter *padapter, u8 *dev_addr, u8 *iface_addr)
@@ -2019,11 +1971,6 @@ int rtw_p2p_enable(struct adapter *padapter, enum P2P_ROLE role)
 			_cancel_timer_ex(&pwdinfo->pre_tx_scan_timer);
 			_cancel_timer_ex(&pwdinfo->reset_ch_sitesurvey);
 			_cancel_timer_ex(&pwdinfo->reset_ch_sitesurvey2);
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
-#else
-			reset_ch_sitesurvey_timer_process(padapter);
-			reset_ch_sitesurvey_timer_process2(padapter);
-#endif
 			rtw_p2p_set_state(pwdinfo, P2P_STATE_NONE);
 			rtw_p2p_set_role(pwdinfo, P2P_ROLE_DISABLE);
 			memset(&pwdinfo->rx_prov_disc_info, 0x00, sizeof(struct rx_provdisc_req_info));
diff --git a/drivers/staging/r8188eu/core/rtw_pwrctrl.c b/drivers/staging/r8188eu/core/rtw_pwrctrl.c
index 56980998e094..a7b63413000b 100644
--- a/drivers/staging/r8188eu/core/rtw_pwrctrl.c
+++ b/drivers/staging/r8188eu/core/rtw_pwrctrl.c
@@ -192,19 +192,11 @@ void rtw_ps_processor(struct adapter *padapter)
 	return;
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 static void pwr_state_check_handler(struct timer_list *t)
-#else
-static void pwr_state_check_handler(void *FunctionContext)
-#endif
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	struct adapter *padapter =
 		from_timer(padapter, t,
 			   pwrctrlpriv.pwr_state_check_timer);
-#else
-	struct adapter *padapter = (struct adapter *)FunctionContext;
-#endif
 	rtw_ps_cmd(padapter);
 }
 
@@ -492,11 +484,7 @@ void rtw_init_pwrctrl_priv(struct adapter *padapter)
 
 	pwrctrlpriv->btcoex_rfon = false;
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	timer_setup(&pwrctrlpriv->pwr_state_check_timer, pwr_state_check_handler, 0);
-#else
-	_init_timer(&(pwrctrlpriv->pwr_state_check_timer), padapter->pnetdev, pwr_state_check_handler, (u8 *)padapter);
-#endif
 }
 
 void rtw_free_pwrctrl_priv(struct adapter *adapter)
diff --git a/drivers/staging/r8188eu/core/rtw_recv.c b/drivers/staging/r8188eu/core/rtw_recv.c
index f3cbf71a3a4a..3872aa5cb982 100644
--- a/drivers/staging/r8188eu/core/rtw_recv.c
+++ b/drivers/staging/r8188eu/core/rtw_recv.c
@@ -25,11 +25,7 @@ static u8 rtw_rfc1042_header[] = {
        0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00
 };
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 void rtw_signal_stat_timer_hdl(struct timer_list *);
-#else
-void rtw_signal_stat_timer_hdl(RTW_TIMER_HDL_ARGS);
-#endif
 
 void _rtw_init_sta_recv_priv(struct sta_recv_priv *psta_recvpriv)
 {
@@ -91,11 +87,7 @@ int _rtw_init_recv_priv(struct recv_priv *precvpriv, struct adapter *padapter)
 
 	res = rtw_hal_init_recv_priv(padapter);
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	timer_setup(&precvpriv->signal_stat_timer, rtw_signal_stat_timer_hdl, 0);
-#else
-	_init_timer(&precvpriv->signal_stat_timer, padapter->pnetdev, RTW_TIMER_HDL_NAME(signal_stat), padapter);
-#endif
 	precvpriv->signal_stat_sampling_interval = 1000; /* ms */
 
 	rtw_set_signal_stat_timer(precvpriv);
@@ -2174,17 +2166,9 @@ s32 rtw_recv_entry(struct recv_frame *precvframe)
 	return ret;
 }
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 void rtw_signal_stat_timer_hdl(struct timer_list *t)
-#else
-void rtw_signal_stat_timer_hdl(RTW_TIMER_HDL_ARGS)
-#endif
 {
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 	struct adapter *adapter = from_timer(adapter, t, recvpriv.signal_stat_timer);
-#else
-	struct adapter *adapter = (struct adapter *)FunctionContext;
-#endif
 	struct recv_priv *recvpriv = &adapter->recvpriv;
 
 	u32 tmp_s, tmp_q;
diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c
index 27d82f91c8a7..c2a3d62facd1 100644
--- a/drivers/staging/r8188eu/core/rtw_xmit.c
+++ b/drivers/staging/r8188eu/core/rtw_xmit.c
@@ -1671,11 +1671,7 @@ static int rtw_br_client_tx(struct adapter *padapter, struct sk_buff **pskb)
 	void *br_port = NULL;
 
 	rcu_read_lock();
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
 	br_port = rcu_dereference(padapter->pnetdev->rx_handler_data);
-#else
-	br_port = rcu_dereference(padapter->pnetdev->br_port);
-#endif
 	rcu_read_unlock();
 	spin_lock_bh(&padapter->br_ext_lock);
 	if (!(skb->data[0] & 1) && br_port &&
@@ -1859,11 +1855,7 @@ s32 rtw_xmit(struct adapter *padapter, struct sk_buff **ppkt)
 	}
 
 	rcu_read_lock();
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
 	br_port = rcu_dereference(padapter->pnetdev->rx_handler_data);
-#else
-	br_port = rcu_dereference(padapter->pnetdev->br_port);
-#endif
 	rcu_read_unlock();
 
 	if (br_port && check_fwstate(pmlmepriv, WIFI_STATION_STATE|WIFI_ADHOC_STATE)) {
diff --git a/drivers/staging/r8188eu/hal/odm.c b/drivers/staging/r8188eu/hal/odm.c
index 81fe727115d9..a26b2ae35b73 100644
--- a/drivers/staging/r8188eu/hal/odm.c
+++ b/drivers/staging/r8188eu/hal/odm.c
@@ -1563,12 +1563,7 @@ void odm_RSSIMonitorCheckAP(struct odm_dm_struct *pDM_Odm)
 
 void ODM_InitAllTimers(struct odm_dm_struct *pDM_Odm)
 {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	ODM_InitializeTimer(pDM_Odm, &pDM_Odm->DM_SWAT_Table.SwAntennaSwitchTimer,
-			    (void *)odm_SwAntDivChkAntSwitchCallback, NULL, "SwAntennaSwitchTimer");
-#else
 	timer_setup(&pDM_Odm->DM_SWAT_Table.SwAntennaSwitchTimer, odm_SwAntDivChkAntSwitchCallback, 0);
-#endif
 }
 
 void ODM_CancelAllTimers(struct odm_dm_struct *pDM_Odm)
@@ -1677,11 +1672,7 @@ void ODM_SwAntDivRestAfterLink(struct odm_dm_struct *pDM_Odm)
 {
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-void odm_SwAntDivChkAntSwitchCallback(void *FunctionContext)
-#else
 void odm_SwAntDivChkAntSwitchCallback(struct timer_list *t)
-#endif
 {
 }
 
diff --git a/drivers/staging/r8188eu/hal/odm_interface.c b/drivers/staging/r8188eu/hal/odm_interface.c
index 8875a9954981..e26a6461e70b 100644
--- a/drivers/staging/r8188eu/hal/odm_interface.c
+++ b/drivers/staging/r8188eu/hal/odm_interface.c
@@ -160,16 +160,6 @@ void ODM_SetTimer(struct odm_dm_struct *pDM_Odm, struct timer_list *pTimer, u32
 	_set_timer(pTimer, msDelay); /* ms */
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-void ODM_InitializeTimer(struct odm_dm_struct *pDM_Odm, struct timer_list *pTimer,
-			 void *CallBackFunc, void *pContext,
-			 const char *szID)
-{
-	struct adapter *Adapter = pDM_Odm->Adapter;
-	_init_timer(pTimer, Adapter->pnetdev, CallBackFunc, pDM_Odm);
-}
-#endif
-
 void ODM_CancelTimer(struct odm_dm_struct *pDM_Odm, struct timer_list *pTimer)
 {
 	_cancel_timer_ex(pTimer);
diff --git a/drivers/staging/r8188eu/include/odm_precomp.h b/drivers/staging/r8188eu/include/odm_precomp.h
index ff2dae597d5b..cec1035e4fe0 100644
--- a/drivers/staging/r8188eu/include/odm_precomp.h
+++ b/drivers/staging/r8188eu/include/odm_precomp.h
@@ -75,11 +75,7 @@ void odm_EdcaTurboCheckCE(struct odm_dm_struct *pDM_Odm);
 void odm_TXPowerTrackingCheckCE(struct odm_dm_struct *pDM_Odm);
 void odm_TXPowerTrackingCheckMP(struct odm_dm_struct *pDM_Odm);
 void odm_TXPowerTrackingCheckAP(struct odm_dm_struct *pDM_Odm);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-void odm_SwAntDivChkAntSwitchCallback(void *FunctionContext);
-#else
 void odm_SwAntDivChkAntSwitchCallback(struct timer_list *t);
-#endif
 void odm_InitHybridAntDiv(struct odm_dm_struct *pDM_Odm);
 void odm_HwAntDiv(struct odm_dm_struct *pDM_Odm);
 
diff --git a/drivers/staging/r8188eu/include/osdep_service.h b/drivers/staging/r8188eu/include/osdep_service.h
index 5b08e985257a..e61113c2608c 100644
--- a/drivers/staging/r8188eu/include/osdep_service.h
+++ b/drivers/staging/r8188eu/include/osdep_service.h
@@ -4,10 +4,7 @@
 #ifndef __OSDEP_SERVICE_H_
 #define __OSDEP_SERVICE_H_
 
-#include <linux/version.h>
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
 #include <linux/sched/signal.h>
-#endif
 #include <basic_types.h>
 
 #define _FAIL		0
@@ -76,15 +73,6 @@ static inline void rtw_list_delete(struct list_head *plist)
 	list_del_init(plist);
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-static inline void _init_timer(struct timer_list *ptimer,struct  net_device *nic_hdl,void *pfunc,void* cntx)
-{
-	ptimer->function = pfunc;
-	ptimer->data = (unsigned long)cntx;
-	init_timer(ptimer);
-}
-#endif
-
 static inline void _set_timer(struct timer_list *ptimer,u32 delay_time)
 {
 	mod_timer(ptimer , (jiffies+(delay_time*HZ/1000)));
diff --git a/drivers/staging/r8188eu/include/rtw_led.h b/drivers/staging/r8188eu/include/rtw_led.h
index 128cdc10b9b5..def9d04a20ce 100644
--- a/drivers/staging/r8188eu/include/rtw_led.h
+++ b/drivers/staging/r8188eu/include/rtw_led.h
@@ -163,11 +163,7 @@ struct led_priv{
 			(adapt)->ledpriv.LedControlHandler((adapt), (action)); \
 	} while (0)
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 15, 0)
 void BlinkTimerCallback(struct timer_list *t);
-#else
-void BlinkTimerCallback(void *data);
-#endif
 void BlinkWorkItemCallback(struct work_struct *work);
 
 void ResetLedStatus(struct LED_871x * pLed);
diff --git a/drivers/staging/r8188eu/include/rtw_mlme.h b/drivers/staging/r8188eu/include/rtw_mlme.h
index 7cab18047cef..3ef1a008c602 100644
--- a/drivers/staging/r8188eu/include/rtw_mlme.h
+++ b/drivers/staging/r8188eu/include/rtw_mlme.h
@@ -453,13 +453,8 @@ void indicate_wx_scan_complete_event(struct adapter *padapter);
 void rtw_indicate_wx_assoc_event(struct adapter *padapter);
 void rtw_indicate_wx_disassoc_event(struct adapter *padapter);
 int event_thread(void *context);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-void rtw_join_timeout_handler (void *FunctionContext);
-void _rtw_scan_timeout_handler(void *FunctionContext);
-#else
 void rtw_join_timeout_handler (struct timer_list *t);
 void _rtw_scan_timeout_handler (struct timer_list *t);
-#endif
 void rtw_free_network_queue(struct adapter *adapter, u8 isfreeall);
 int rtw_init_mlme_priv(struct adapter *adapter);
 void rtw_free_mlme_priv (struct mlme_priv *pmlmepriv);
diff --git a/drivers/staging/r8188eu/include/rtw_security.h b/drivers/staging/r8188eu/include/rtw_security.h
index 6e039e87b04d..2d8522c01027 100644
--- a/drivers/staging/r8188eu/include/rtw_security.h
+++ b/drivers/staging/r8188eu/include/rtw_security.h
@@ -152,14 +152,6 @@ struct security_priv {
 	u8 bWepDefaultKeyIdxSet;
 };
 
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(5, 8, 0)
-struct sha256_state {
-	u64 length;
-	u32 state[8], curlen;
-	u8 buf[64];
-};
-#endif
-
 #define GET_ENCRY_ALGO(psecuritypriv, psta, encry_algo, bmcst)		\
 do {									\
 	switch (psecuritypriv->dot11AuthAlgrthm) {			\
diff --git a/drivers/staging/r8188eu/include/usb_ops.h b/drivers/staging/r8188eu/include/usb_ops.h
index 40e834390a10..9e60b3a9a02a 100644
--- a/drivers/staging/r8188eu/include/usb_ops.h
+++ b/drivers/staging/r8188eu/include/usb_ops.h
@@ -4,7 +4,6 @@
 #ifndef __USB_OPS_H_
 #define __USB_OPS_H_
 
-#include <linux/version.h>
 #include <osdep_service.h>
 #include <drv_types.h>
 #include <osdep_intf.h>
@@ -22,7 +21,6 @@ enum {
 #define MAX_VENDOR_REQ_CMD_SIZE	254	/* 8188cu SIE Support */
 #define MAX_USB_IO_CTL_SIZE	(MAX_VENDOR_REQ_CMD_SIZE + ALIGNMENT_UNIT)
 
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 12))
 #define rtw_usb_control_msg(dev, pipe, request, requesttype,		\
 			    value, index, data, size, timeout_ms)	\
 	usb_control_msg((dev), (pipe), (request), (requesttype), (value),\
@@ -30,20 +28,6 @@ enum {
 #define rtw_usb_bulk_msg(usb_dev, pipe, data, len, actual_length, timeout_ms) \
 	usb_bulk_msg((usb_dev), (pipe), (data), (len),			\
 		     (actual_length), (timeout_ms))
-#else
-#define rtw_usb_control_msg(dev, pipe, request, requesttype,		\
-			    value, index, data, size, timeout_ms)	\
-	usb_control_msg((dev), (pipe), (request), (requesttype),	\
-			(value), (index), (data), (size),		\
-			((timeout_ms) == 0) ||				\
-			((timeout_ms)*HZ/1000 > 0) ?			\
-			((timeout_ms)*HZ/1000) : 1)
-#define rtw_usb_bulk_msg(usb_dev, pipe, data, len,			\
-			 actual_length, timeout_ms) \
-	usb_bulk_msg((usb_dev), (pipe), (data), (len), (actual_length), \
-		     ((timeout_ms) == 0) || ((timeout_ms)*HZ/1000 > 0) ?\
-		     ((timeout_ms)*HZ/1000) : 1)
-#endif
 #include <usb_ops_linux.h>
 
 void rtl8188eu_set_hw_type(struct adapter *padapter);
diff --git a/drivers/staging/r8188eu/include/wifi.h b/drivers/staging/r8188eu/include/wifi.h
index 9760989ffc4c..2c56d1d70d03 100644
--- a/drivers/staging/r8188eu/include/wifi.h
+++ b/drivers/staging/r8188eu/include/wifi.h
@@ -714,9 +714,6 @@ enum ht_cap_ampdu_factor {
  * According to IEEE802.11n spec size varies from 8K to 64K (in powers of 2)
  */
 #define IEEE80211_MIN_AMPDU_BUF 0x8
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(4,19,0))
-#define IEEE80211_MAX_AMPDU_BUF 0x40
-#endif
 
 /* Spatial Multiplexing Power Save Modes */
 #define WLAN_HT_CAP_SM_PS_STATIC	0
diff --git a/drivers/staging/r8188eu/os_dep/mlme_linux.c b/drivers/staging/r8188eu/os_dep/mlme_linux.c
index 22d37e994101..8d78b8697016 100644
--- a/drivers/staging/r8188eu/os_dep/mlme_linux.c
+++ b/drivers/staging/r8188eu/os_dep/mlme_linux.c
@@ -7,47 +7,23 @@
 #include <drv_types.h>
 #include <mlme_osdep.h>
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-void rtw_join_timeout_handler (void *FunctionContext)
-#else
 void rtw_join_timeout_handler (struct timer_list *t)
-#endif
 {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	struct adapter *adapter = (struct adapter *)FunctionContext;
-#else
 	struct adapter *adapter = from_timer(adapter, t, mlmepriv.assoc_timer);
-#endif
 
 	_rtw_join_timeout_handler(adapter);
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-void _rtw_scan_timeout_handler (void *FunctionContext)
-#else
 void _rtw_scan_timeout_handler (struct timer_list *t)
-#endif
 {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	struct adapter *adapter = (struct adapter *)FunctionContext;
-#else
 	struct adapter *adapter = from_timer(adapter, t, mlmepriv.scan_to_timer);
-#endif
 
 	rtw_scan_timeout_handler(adapter);
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-static void _dynamic_check_timer_handlder(void *FunctionContext)
-#else
 static void _dynamic_check_timer_handlder(struct timer_list *t)
-#endif
 {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	struct adapter *adapter = (struct adapter *)FunctionContext;
-#else
 	struct adapter *adapter = from_timer(adapter, t, mlmepriv.dynamic_chk_timer);
-#endif
 
 	if (adapter->registrypriv.mp_mode == 1)
 		return;
@@ -59,15 +35,9 @@ void rtw_init_mlme_timer(struct adapter *padapter)
 {
 	struct	mlme_priv *pmlmepriv = &padapter->mlmepriv;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	_init_timer(&(pmlmepriv->assoc_timer), padapter->pnetdev, rtw_join_timeout_handler, padapter);
-	_init_timer(&(pmlmepriv->scan_to_timer), padapter->pnetdev, _rtw_scan_timeout_handler, padapter);
-	_init_timer(&(pmlmepriv->dynamic_chk_timer), padapter->pnetdev, _dynamic_check_timer_handlder, padapter);
-#else
 	timer_setup(&pmlmepriv->assoc_timer, rtw_join_timeout_handler, 0);
 	timer_setup(&pmlmepriv->scan_to_timer, _rtw_scan_timeout_handler, 0);
 	timer_setup(&pmlmepriv->dynamic_chk_timer, _dynamic_check_timer_handlder, 0);
-#endif
 }
 
 void rtw_os_indicate_connect(struct adapter *adapter)
@@ -169,69 +139,36 @@ void rtw_report_sec_ie(struct adapter *adapter, u8 authmode, u8 *sec_ie)
 	}
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-static void _survey_timer_hdl(void *FunctionContext)
-#else
 static void _survey_timer_hdl(struct timer_list *t)
-#endif
 {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	struct adapter *padapter = (struct adapter *)FunctionContext;
-#else
 	struct adapter *padapter = from_timer(padapter, t, mlmeextpriv.survey_timer);
-#endif
 
 	survey_timer_hdl(padapter);
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-static void _link_timer_hdl(void *FunctionContext)
-#else
 static void _link_timer_hdl(struct timer_list *t)
-#endif
 {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	struct adapter *padapter = (struct adapter *)FunctionContext;
-#else
 	struct adapter *padapter = from_timer(padapter, t, mlmeextpriv.link_timer);
-#endif
 	link_timer_hdl(padapter);
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-static void _addba_timer_hdl(void *FunctionContext)
-#else
 static void _addba_timer_hdl(struct timer_list *t)
-#endif
 {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	struct sta_info *psta = (struct sta_info *)FunctionContext;
-#else
 	struct sta_info *psta = from_timer(psta, t, addba_retry_timer);
-#endif
 	addba_timer_hdl(psta);
 }
 
 void init_addba_retry_timer(struct adapter *padapter, struct sta_info *psta)
 {
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	_init_timer(&psta->addba_retry_timer, padapter->pnetdev, _addba_timer_hdl, psta);
-#else
 	timer_setup(&psta->addba_retry_timer, _addba_timer_hdl, 0);
-#endif
 }
 
 void init_mlme_ext_timer(struct adapter *padapter)
 {
 	struct	mlme_ext_priv *pmlmeext = &padapter->mlmeextpriv;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	_init_timer(&pmlmeext->survey_timer, padapter->pnetdev, _survey_timer_hdl, padapter);
-	_init_timer(&pmlmeext->link_timer, padapter->pnetdev, _link_timer_hdl, padapter);
-#else
 	timer_setup(&pmlmeext->survey_timer, _survey_timer_hdl, 0);
 	timer_setup(&pmlmeext->link_timer, _link_timer_hdl, 0);
-#endif
 }
 
 #ifdef CONFIG_88EU_AP_MODE
diff --git a/drivers/staging/r8188eu/os_dep/os_intfs.c b/drivers/staging/r8188eu/os_dep/os_intfs.c
index 2cf91516d739..454b94b037f3 100644
--- a/drivers/staging/r8188eu/os_dep/os_intfs.c
+++ b/drivers/staging/r8188eu/os_dep/os_intfs.c
@@ -3,7 +3,6 @@
 
 #define _OS_INTFS_C_
 
-#include <linux/version.h>
 #include <osdep_service.h>
 #include <drv_types.h>
 #include <xmit_osdep.h>
diff --git a/drivers/staging/r8188eu/os_dep/recv_linux.c b/drivers/staging/r8188eu/os_dep/recv_linux.c
index 558050c62bb1..5af8ffac870b 100644
--- a/drivers/staging/r8188eu/os_dep/recv_linux.c
+++ b/drivers/staging/r8188eu/os_dep/recv_linux.c
@@ -179,11 +179,7 @@ int rtw_recv_indicatepkt(struct adapter *padapter,
 	}
 
 	rcu_read_lock();
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
 	rcu_dereference(padapter->pnetdev->rx_handler_data);
-#else
-	rcu_dereference(padapter->pnetdev->br_port);
-#endif
 	rcu_read_unlock();
 
 	skb->ip_summed = CHECKSUM_NONE;
@@ -226,19 +222,11 @@ void rtw_os_read_port(struct adapter *padapter, struct recv_buf *precvbuf)
 			      (unsigned char *)precvbuf);
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-static void _rtw_reordering_ctrl_timeout_handler(void *func_context)
-#else
 static void _rtw_reordering_ctrl_timeout_handler(struct timer_list *t)
-#endif
 {
 	struct recv_reorder_ctrl *preorder_ctrl;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	preorder_ctrl = (struct recv_reorder_ctrl *)func_context;
-#else
 	preorder_ctrl = from_timer(preorder_ctrl, t, reordering_ctrl_timer);
-#endif
 	rtw_reordering_ctrl_timeout_handler(preorder_ctrl);
 }
 
@@ -246,9 +234,5 @@ void rtw_init_recv_timer(struct recv_reorder_ctrl *preorder_ctrl)
 {
 	struct adapter *padapter = preorder_ctrl->padapter;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 15, 0)
-	_init_timer(&(preorder_ctrl->reordering_ctrl_timer), padapter->pnetdev, _rtw_reordering_ctrl_timeout_handler, preorder_ctrl);
-#else
 	timer_setup(&preorder_ctrl->reordering_ctrl_timer, _rtw_reordering_ctrl_timeout_handler, 0);
-#endif
 }