[ofw] [Patch][IPoIB_NIDS6_CM] Adding shutter_shut for Adapter Reset flow

[Smith, Stan]

Please see comments below.

________________________________
From: ofw-bounces at lists.openfabrics.org [mailto:ofw-bounces at lists.openfabrics.org] On Behalf Of Alex Naslednikov
Sent: Wednesday, October 06, 2010 4:13 AM
To: ofw at lists.openfabrics.org
Subject: [ofw] [Patch][IPoIB_NIDS6_CM] Adding shutter_shut for Adapter Reset flow

The patch below prevents race with BSOD when NDIS call receive callback of ipoib while
some ipoib global objects are under destruction (like p_adapter ->p_port).
It was tested by night regression run on IPoIB driver
---
Adding shutter_shut for Adapter Reset flow
Signed-off by: Alexander Naslednikov (xalex at mellanox.co.il)

Index: kernel/ipoib_adapter.cpp
===================================================================
--- kernel/ipoib_adapter.cpp      (revision 2938)
+++ kernel/ipoib_adapter.cpp   (working copy)
@@ -988,10 +988,13 @@
                p_adapter->reset = TRUE;

                if( p_adapter->h_pnp )
-              {
+             {
+                           Why the extra blank line? Please remove.
                                h_pnp = p_adapter->h_pnp;
                                p_adapter->h_pnp  = NULL;
                                status = p_adapter->p_ifc->dereg_pnp( h_pnp, __ipoib_pnp_dereg );
+                             // Wait until NDIS will return all indicated NBLs that were received
+                             shutter_shut( &p_adapter->recv_shutter );

I'm a bit concerned in that shutter_shut( &p_adapter->recv_shutter) could be called twice as 'ipoib_shutdown_ex()' also calls
shutter_shut( &p_adapter->recv_shutter) and then the PNP callback would also call shutter_shut( &p_adapter->recv_shutter) ?
I do not see a checked build assert() from shutter.h for shutter_shut() being called on the same shutter, so it must be OK?
Thoughts?

Otherwise the patch looks OK and tests OK.

                                if( status == IB_SUCCESS )
                                                status = IB_NOT_DONE;
                }
Index: kernel/ipoib_port.cpp
===================================================================
--- kernel/ipoib_port.cpp             (revision 2946)
+++ kernel/ipoib_port.cpp          (working copy)
@@ -830,11 +830,15 @@
                IPOIB_PRINT( TRACE_LEVEL_ERROR, IPOIB_DBG_OBJ,
                                ("ref type %d ref_cnt %d\n", ref_init, p_port->obj.ref_cnt) );
 #endif
-              // The port is started as paused and NDIS calls latter to ipoib_restart. We
-              // shut the recv_shuter for now and alive it on ipoib_restart. We did
-              // it in this way since MpInitializeInternal also calls in reset and than
-              // we need to set the rec ref count to 1 //TODO !!!!!!!!!!1
-              //
+             /* The steps of the initialization are as depicted below:
+             I.            adapter_init() calls shutter_init(), the shutter counter is set to 0
+             II.            ipoib_pnp_cb() calls to ipoib_port_init() that calls to __port_init() that SHOULD set shutter counter to -MAX_OPERATIONS
+                             That is, the code below should call to shutter_shut()
+             III.NDIS calls to ipoib_restart() that calls to shutter_alive. Now, shutter_counter is again 0.
+             IV.          NDIS call to ipoib_pause() that sets the adapter to pause state, calls to shutter_shut.
+                             Now, the counter is again equals to -MAX_OPERATIONS
+             V.            NDIS calls to ipoib_restart that calls to shutter_alive. Shutter counter is 0 and we can start working
+             */

                if ( p_adapter->ipoib_state == IPOIB_INIT) {
                                IPOIB_PRINT( TRACE_LEVEL_INFORMATION, IPOIB_DBG_RECV,

Alexander (XaleX) Naslednikov
SW Networking Team
Mellanox Technologies

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