[NIU]: Fix slowpath interrupt handling.

niu_slowpath_interrupt() expects values to be setup in lp->{v0,v1,v2}
but they aren't.  That's only done by niu_schedule_napi() which is
done later in the interrupt path.

If niu_rx_error() returns zero, and v0 is clear, hit the
RX_DMA_CTL_STATE register with a RX_DMA_CTL_STAT_MEX.

Only emit verbose RX error logs if a fatal channel or port error is
signalled.  Other cases will be recorded into statistics by
niu_log_rxchan_errors().

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 23 insertions, 11 deletions

diff --git a/drivers/net/niu.c b/drivers/net/niu.c
index abfc61c3a38c..32ed87d54706 100644
--- a/drivers/net/niu.c
+++ b/drivers/net/niu.c
@@ -2508,15 +2508,19 @@ static int niu_rx_error(struct niu *np, struct rx_ring_info *rp)
         u64 stat = nr64(RX_DMA_CTL_STAT(rp->rx_channel));
         int err = 0;
 
-        dev_err(np->device, PFX "%s: RX channel %u error, stat[%llx]\n",
-                np->dev->name, rp->rx_channel, (unsigned long long) stat);
-
-        niu_log_rxchan_errors(np, rp, stat);
 
         if (stat & (RX_DMA_CTL_STAT_CHAN_FATAL |
                     RX_DMA_CTL_STAT_PORT_FATAL))
                 err = -EINVAL;
 
+        if (err) {
+                dev_err(np->device, PFX "%s: RX channel %u error, stat[%llx]\n",
+                        np->dev->name, rp->rx_channel,
+                        (unsigned long long) stat);
+
+                niu_log_rxchan_errors(np, rp, stat);
+        }
+
         nw64(RX_DMA_CTL_STAT(rp->rx_channel),
              stat & RX_DMA_CTL_WRITE_CLEAR_ERRS);
 
@@ -2749,13 +2753,16 @@ static int niu_device_error(struct niu *np)
         return -ENODEV;
 }
 
-static int niu_slowpath_interrupt(struct niu *np, struct niu_ldg *lp)
+static int niu_slowpath_interrupt(struct niu *np, struct niu_ldg *lp,
+                              u64 v0, u64 v1, u64 v2)
 {
-        u64 v0 = lp->v0;
-        u64 v1 = lp->v1;
-        u64 v2 = lp->v2;
+
         int i, err = 0;
 
+        lp->v0 = v0;
+        lp->v1 = v1;
+        lp->v2 = v2;
+
         if (v1 & 0x00000000ffffffffULL) {
                 u32 rx_vec = (v1 & 0xffffffff);
 
@@ -2764,8 +2771,13 @@ static int niu_slowpath_interrupt(struct niu *np, struct niu_ldg *lp)
 
                         if (rx_vec & (1 << rp->rx_channel)) {
                                 int r = niu_rx_error(np, rp);
-                                if (r)
+                                if (r) {
                                         err = r;
+                                } else {
+                                        if (!v0)
+                                                nw64(RX_DMA_CTL_STAT(rp->rx_channel),
+                                                     RX_DMA_CTL_STAT_MEX);
+                                }
                         }
                 }
         }
@@ -2803,7 +2815,7 @@ static int niu_slowpath_interrupt(struct niu *np, struct niu_ldg *lp)
         if (err)
                 niu_enable_interrupts(np, 0);
 
-        return -EINVAL;
+        return err;
 }
 
 static void niu_rxchan_intr(struct niu *np, struct rx_ring_info *rp,
@@ -2905,7 +2917,7 @@ static irqreturn_t niu_interrupt(int irq, void *dev_id)
         }
 
         if (unlikely((v0 & ((u64)1 << LDN_MIF)) || v1 || v2)) {
-                int err = niu_slowpath_interrupt(np, lp);
+                int err = niu_slowpath_interrupt(np, lp, v0, v1, v2);
                 if (err)
                         goto out;
         }