[PATCH 4.9 068/108] r8152: avoid start_xmit to call napi_schedule during autosuspend

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: hayeswang <hayesw...@realtek.com>


[ Upstream commit 26afec39306926654e9cd320f19bbf3685bb0997 ]

Adjust the setting of the flag of SELECTIVE_SUSPEND to prevent start_xmit()
from calling napi_schedule() directly during runtime suspend.

After calling napi_disable() or clearing the flag of WORK_ENABLE,
scheduling the napi is useless.

Signed-off-by: Hayes Wang <hayesw...@realtek.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Sasha Levin <alexander.le...@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/net/usb/r8152.c |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -3583,10 +3583,15 @@ static int rtl8152_rumtime_suspend(struc
        struct net_device *netdev = tp->netdev;
        int ret = 0;
 
+       set_bit(SELECTIVE_SUSPEND, &tp->flags);
+       smp_mb__after_atomic();
+
        if (netif_running(netdev) && test_bit(WORK_ENABLE, &tp->flags)) {
                u32 rcr = 0;
 
                if (delay_autosuspend(tp)) {
+                       clear_bit(SELECTIVE_SUSPEND, &tp->flags);
+                       smp_mb__after_atomic();
                        ret = -EBUSY;
                        goto out1;
                }
@@ -3603,6 +3608,8 @@ static int rtl8152_rumtime_suspend(struc
                        if (!(ocp_data & RXFIFO_EMPTY)) {
                                rxdy_gated_en(tp, false);
                                ocp_write_dword(tp, MCU_TYPE_PLA, PLA_RCR, rcr);
+                               clear_bit(SELECTIVE_SUSPEND, &tp->flags);
+                               smp_mb__after_atomic();
                                ret = -EBUSY;
                                goto out1;
                        }
@@ -3622,8 +3629,6 @@ static int rtl8152_rumtime_suspend(struc
                }
        }
 
-       set_bit(SELECTIVE_SUSPEND, &tp->flags);
-
 out1:
        return ret;
 }
@@ -3679,12 +3684,13 @@ static int rtl8152_resume(struct usb_int
        if (netif_running(tp->netdev) && tp->netdev->flags & IFF_UP) {
                if (test_bit(SELECTIVE_SUSPEND, &tp->flags)) {
                        tp->rtl_ops.autosuspend_en(tp, false);
-                       clear_bit(SELECTIVE_SUSPEND, &tp->flags);
                        napi_disable(&tp->napi);
                        set_bit(WORK_ENABLE, &tp->flags);
                        if (netif_carrier_ok(tp->netdev))
                                rtl_start_rx(tp);
                        napi_enable(&tp->napi);
+                       clear_bit(SELECTIVE_SUSPEND, &tp->flags);
+                       smp_mb__after_atomic();
                } else {
                        tp->rtl_ops.up(tp);
                        netif_carrier_off(tp->netdev);