[PATCH net] r8152: set RTL8152_UNPLUG only for real disconnection

From: Hayes Wang
Date: Thu Jul 04 2019 - 05:37:55 EST


Set the flag of RTL8152_UNPLUG if and only if the device is unplugged.
Some error codes sometimes don't mean the real disconnection of usb device.
For those situations, set the flag of RTL8152_UNPLUG causes the driver skips
some flows of disabling the device, and it let the device stay at incorrect
state.

Signed-off-by: Hayes Wang <hayeswang@xxxxxxxxxxx>
---
drivers/net/usb/r8152.c | 27 ++++++++++++++++-----------
1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index e887ac86fbef..39e0768d734d 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -28,7 +28,7 @@
#define NETNEXT_VERSION "09"

/* Information for net */
-#define NET_VERSION "9"
+#define NET_VERSION "10"

#define DRIVER_VERSION "v1." NETNEXT_VERSION "." NET_VERSION
#define DRIVER_AUTHOR "Realtek linux nic maintainers <nic_swsd@xxxxxxxxxxx>"
@@ -825,6 +825,14 @@ int set_registers(struct r8152 *tp, u16 value, u16 index, u16 size, void *data)
return ret;
}

+static void rtl_set_unplug(struct r8152 *tp)
+{
+ if (tp->udev->state == USB_STATE_NOTATTACHED) {
+ set_bit(RTL8152_UNPLUG, &tp->flags);
+ smp_mb__after_atomic();
+ }
+}
+
static int generic_ocp_read(struct r8152 *tp, u16 index, u16 size,
void *data, u16 type)
{
@@ -863,7 +871,7 @@ static int generic_ocp_read(struct r8152 *tp, u16 index, u16 size,
}

if (ret == -ENODEV)
- set_bit(RTL8152_UNPLUG, &tp->flags);
+ rtl_set_unplug(tp);

return ret;
}
@@ -933,7 +941,7 @@ static int generic_ocp_write(struct r8152 *tp, u16 index, u16 byteen,

error1:
if (ret == -ENODEV)
- set_bit(RTL8152_UNPLUG, &tp->flags);
+ rtl_set_unplug(tp);

return ret;
}
@@ -1321,7 +1329,7 @@ static void read_bulk_callback(struct urb *urb)
napi_schedule(&tp->napi);
return;
case -ESHUTDOWN:
- set_bit(RTL8152_UNPLUG, &tp->flags);
+ rtl_set_unplug(tp);
netif_device_detach(tp->netdev);
return;
case -ENOENT:
@@ -1441,7 +1449,7 @@ static void intr_callback(struct urb *urb)
resubmit:
res = usb_submit_urb(urb, GFP_ATOMIC);
if (res == -ENODEV) {
- set_bit(RTL8152_UNPLUG, &tp->flags);
+ rtl_set_unplug(tp);
netif_device_detach(tp->netdev);
} else if (res) {
netif_err(tp, intr, tp->netdev,
@@ -2036,7 +2044,7 @@ static void tx_bottom(struct r8152 *tp)
struct net_device *netdev = tp->netdev;

if (res == -ENODEV) {
- set_bit(RTL8152_UNPLUG, &tp->flags);
+ rtl_set_unplug(tp);
netif_device_detach(netdev);
} else {
struct net_device_stats *stats = &netdev->stats;
@@ -2110,7 +2118,7 @@ int r8152_submit_rx(struct r8152 *tp, struct rx_agg *agg, gfp_t mem_flags)

ret = usb_submit_urb(agg->urb, mem_flags);
if (ret == -ENODEV) {
- set_bit(RTL8152_UNPLUG, &tp->flags);
+ rtl_set_unplug(tp);
netif_device_detach(tp->netdev);
} else if (ret) {
struct urb *urb = agg->urb;
@@ -5355,10 +5363,7 @@ static void rtl8152_disconnect(struct usb_interface *intf)

usb_set_intfdata(intf, NULL);
if (tp) {
- struct usb_device *udev = tp->udev;
-
- if (udev->state == USB_STATE_NOTATTACHED)
- set_bit(RTL8152_UNPLUG, &tp->flags);
+ rtl_set_unplug(tp);

netif_napi_del(&tp->napi);
unregister_netdev(tp->netdev);
--
2.21.0