From: =?UTF-8?q?Bj=C3=B6rn=20T=C3=B6pel?= <bjorn.topel@intel.com>
Date: Fri, 12 Jun 2020 13:47:31 +0200
Subject: i40e: fix crash when Rx descriptor count is changed
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Patch-mainline: v5.8-rc3
Git-commit: 3995ecbabc6f8019b3a55aeb551eeb9598b8b354
References: jsc#SLE-13701

When the AF_XDP buffer allocator was introduced, the Rx SW ring
"rx_bi" allocation was moved from i40e_setup_rx_descriptors()
function, and was instead done in the i40e_configure_rx_ring()
function.

This broke the ethtool set_ringparam() hook for changing the Rx
descriptor count, which was relying on i40e_setup_rx_descriptors() to
handle the allocation.

Fix this by adding an explicit i40e_alloc_rx_bi() call to
i40e_set_ringparam().

Fixes: be1222b585fd ("i40e: Separate kernel allocated rx_bi rings from AF_XDP rings")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/intel/i40e/i40e_ethtool.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ethtool.c
@@ -2072,6 +2072,9 @@ static int i40e_set_ringparam(struct net
 			err = i40e_setup_rx_descriptors(&rx_rings[i]);
 			if (err)
 				goto rx_unwind;
+			err = i40e_alloc_rx_bi(&rx_rings[i]);
+			if (err)
+				goto rx_unwind;
 
 			/* now allocate the Rx buffers to make sure the OS
 			 * has enough memory, any failure here means abort