Re: [PATCH net 1/4] r8152: avoid start_xmit to call napi_schedule during autosuspend

[Stephen Hemminger]

On Wed, 25 Jan 2017 10:50:51 +0800
Hayes Wang  wrote:

> 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 
> ---
>  drivers/net/usb/r8152.c | 8 +---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
> index e1466b4..27b0b44 100644
> --- a/drivers/net/usb/r8152.c
> +++ b/drivers/net/usb/r8152.c
> @@ -3585,10 +3585,13 @@ static int rtl8152_rumtime_suspend(struct r8152 *tp)
>   struct net_device *netdev = tp->netdev;
>   int ret = 0;
>  
> + set_bit(SELECTIVE_SUSPEND, >flags);
> +
>   if (netif_running(netdev) && test_bit(WORK_ENABLE, >flags)) {
>   u32 rcr = 0;
>  
>   if (delay_autosuspend(tp)) {
> + clear_bit(SELECTIVE_SUSPEND, >flags);
>   ret = -EBUSY;
>   goto out1;
>   }
> @@ -3605,6 +3608,7 @@ static int rtl8152_rumtime_suspend(struct r8152 *tp)
>   if (!(ocp_data & RXFIFO_EMPTY)) {
>   rxdy_gated_en(tp, false);
>   ocp_write_dword(tp, MCU_TYPE_PLA, PLA_RCR, rcr);
> + clear_bit(SELECTIVE_SUSPEND, >flags);
>   ret = -EBUSY;

If you are going to start using bit operations then you may need 
smp_mb_before/after_atomic.

[PATCH net 1/4] r8152: avoid start_xmit to call napi_schedule during autosuspend

[Hayes Wang]

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 
---
 drivers/net/usb/r8152.c | 8 +---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index e1466b4..27b0b44 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -3585,10 +3585,13 @@ static int rtl8152_rumtime_suspend(struct r8152 *tp)
struct net_device *netdev = tp->netdev;
int ret = 0;
 
+   set_bit(SELECTIVE_SUSPEND, >flags);
+
if (netif_running(netdev) && test_bit(WORK_ENABLE, >flags)) {
u32 rcr = 0;
 
if (delay_autosuspend(tp)) {
+   clear_bit(SELECTIVE_SUSPEND, >flags);
ret = -EBUSY;
goto out1;
}
@@ -3605,6 +3608,7 @@ static int rtl8152_rumtime_suspend(struct r8152 *tp)
if (!(ocp_data & RXFIFO_EMPTY)) {
rxdy_gated_en(tp, false);
ocp_write_dword(tp, MCU_TYPE_PLA, PLA_RCR, rcr);
+   clear_bit(SELECTIVE_SUSPEND, >flags);
ret = -EBUSY;
goto out1;
}
@@ -3624,8 +3628,6 @@ static int rtl8152_rumtime_suspend(struct r8152 *tp)
}
}
 
-   set_bit(SELECTIVE_SUSPEND, >flags);
-
 out1:
return ret;
 }
@@ -3681,12 +3683,12 @@ static int rtl8152_resume(struct usb_interface *intf)
if (netif_running(tp->netdev) && tp->netdev->flags & IFF_UP) {
if (test_bit(SELECTIVE_SUSPEND, >flags)) {
tp->rtl_ops.autosuspend_en(tp, false);
-   clear_bit(SELECTIVE_SUSPEND, >flags);
napi_disable(>napi);
set_bit(WORK_ENABLE, >flags);
if (netif_carrier_ok(tp->netdev))
rtl_start_rx(tp);
napi_enable(>napi);
+   clear_bit(SELECTIVE_SUSPEND, >flags);
} else {
tp->rtl_ops.up(tp);
netif_carrier_off(tp->netdev);
-- 
2.7.4