netdev - [PATCH net 1/2] ibmvnic: drop bad optimization in reuse_rx

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Message-Id: <20211201054836.3488211-1-sukadev@linux.ibm.com>
Date:   Tue, 30 Nov 2021 21:48:35 -0800
From:   Sukadev Bhattiprolu <sukadev@...ux.ibm.com>
To:     netdev@...r.kernel.org
Cc:     Brian King <brking@...ux.ibm.com>, Dany Madden <drt@...ux.ibm.com>,
        Rick Lindsley <ricklind@...ux.ibm.com>
Subject: [PATCH net 1/2] ibmvnic: drop bad optimization in reuse_rx_pools()

When trying to decide whether or not reuse existing rx/tx pools
we tried to allow a range of values for the pool parameters rather
than exact matches. This was intended to reuse the resources for
instance when switching between two VIO servers with different
default parameters.

But this optimization is incomplete and breaks when we try to
change the number of queues for instance. The optimization needs
to be updated, so drop it for now and simplify the code.

Fixes: 489de956e7a2 ("ibmvnic: Reuse rx pools when possible")
Reported-by: Dany Madden <drt@...ux.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@...ux.ibm.com>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 3cca51735421..6df92a872f0f 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -628,17 +628,9 @@ static bool reuse_rx_pools(struct ibmvnic_adapter *adapter)
 	old_buff_size = adapter->prev_rx_buf_sz;
 	new_buff_size = adapter->cur_rx_buf_sz;
 
-	/* Require buff size to be exactly same for now */
-	if (old_buff_size != new_buff_size)
-		return false;
-
-	if (old_num_pools == new_num_pools && old_pool_size == new_pool_size)
-		return true;
-
-	if (old_num_pools < adapter->min_rx_queues ||
-	    old_num_pools > adapter->max_rx_queues ||
-	    old_pool_size < adapter->min_rx_add_entries_per_subcrq ||
-	    old_pool_size > adapter->max_rx_add_entries_per_subcrq)
+	if (old_buff_size != new_buff_size ||
+	    old_num_pools != new_num_pools ||
+	    old_pool_size != new_pool_size)
 		return false;
 
 	return true;
-- 
2.27.0