net: eqos: fix bug in qinx calculation

qinx calculation assumed that irq numbers returned from platform_get_irq()
will be linearly mapped based on hwirq. This is not the case with kernel v4.4.

This leads wrong qinx and so there was a flood of interrupts causing 
soft lockup.

Fixing by comparing actual values without any assumption of irq ordering.

Bug 200195187

Change-Id: I80b9f9135606e37c4e25e7847d3ed972f4e7a586
Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
Reviewed-on: http://git-master/r/1147711
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: David Lim <dlim@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Tested-by: Bharat Nihalani <bnihalani@nvidia.com>

1 files changed, 8 insertions, 4 deletions

diff --git a/drivers/net/ethernet/nvidia/eqos/drv.c b/drivers/net/ethernet/nvidia/eqos/drv.c
index 2c56f3bda..e2532a9b0 100644
--- a/drivers/net/ethernet/nvidia/eqos/drv.c
+++ b/drivers/net/ethernet/nvidia/eqos/drv.c
@@ -519,10 +519,14 @@ irqreturn_t eqos_ch_isr(int irq, void *device_id)
 
         i = smp_processor_id();
 
-        if (irq < pdata->rx_irqs[0])
-                qinx = irq - pdata->tx_irqs[0];
-        else
-                qinx = irq - pdata->rx_irqs[0];
+        if ((irq == pdata->rx_irqs[0]) || (irq == pdata->tx_irqs[0]))
+                qinx = 0;
+        else if ((irq == pdata->rx_irqs[1]) || (irq == pdata->tx_irqs[1]))
+                qinx = 1;
+        else if ((irq == pdata->rx_irqs[2]) || (irq == pdata->tx_irqs[2]))
+                qinx = 2;
+        else if ((irq == pdata->rx_irqs[3]) || (irq == pdata->tx_irqs[3]))
+                qinx = 3;
 
         DBGPR("-->%s(): cpu=%d, chan=%d\n", __func__, i, qinx);