diff mbox series

[net,1/3] bnxt_en: Fix possible bnxt_open() failure caused by wrong RFS flag

Message ID 1651540392-2260-2-git-send-email-michael.chan@broadcom.com (mailing list archive)
State Accepted
Commit 13ba794397e45e52893cfc21d7a69cb5f341b407
Delegated to: Netdev Maintainers
Headers show
Series bnxt_en: Bug fixes | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/cc_maintainers warning 2 maintainers not CCed: edumazet@google.com pabeni@redhat.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/checkpatch warning WARNING: line length of 97 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Michael Chan May 3, 2022, 1:13 a.m. UTC 
From: Somnath Kotur <somnath.kotur@broadcom.com>

bnxt_open() can fail in this code path, especially on a VF when
it fails to reserve default rings:

bnxt_open()
  __bnxt_open_nic()
    bnxt_clear_int_mode()
    bnxt_init_dflt_ring_mode()

RX rings would be set to 0 when we hit this error path.

It is possible for a subsequent bnxt_open() call to potentially succeed
with a code path like this:

bnxt_open()
  bnxt_hwrm_if_change()
    bnxt_fw_init_one()
      bnxt_fw_init_one_p3()
        bnxt_set_dflt_rfs()
          bnxt_rfs_capable()
            bnxt_hwrm_reserve_rings()

On older chips, RFS is capable if we can reserve the number of vnics that
is equal to RX rings + 1.  But since RX rings is still set to 0 in this
code path, we may mistakenly think that RFS is supported for 0 RX rings.

Later, when the default RX rings are reserved and we try to enable
RFS, it would fail and cause bnxt_open() to fail unnecessarily.

We fix this in 2 places.  bnxt_rfs_capable() will always return false if
RX rings is not yet set.  bnxt_init_dflt_ring_mode() will call
bnxt_set_dflt_rfs() which will always clear the RFS flags if RFS is not
supported.

Fixes: 20d7d1c5c9b1 ("bnxt_en: reliably allocate IRQ table on reset to avoid crash")
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 874fad0a5cf8..2818cfef42f8 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -10983,7 +10983,7 @@  static bool bnxt_rfs_capable(struct bnxt *bp)
 
 	if (bp->flags & BNXT_FLAG_CHIP_P5)
 		return bnxt_rfs_supported(bp);
-	if (!(bp->flags & BNXT_FLAG_MSIX_CAP) || !bnxt_can_reserve_rings(bp))
+	if (!(bp->flags & BNXT_FLAG_MSIX_CAP) || !bnxt_can_reserve_rings(bp) || !bp->rx_nr_rings)
 		return false;
 
 	vnics = 1 + bp->rx_nr_rings;
@@ -13234,10 +13234,9 @@  static int bnxt_init_dflt_ring_mode(struct bnxt *bp)
 		goto init_dflt_ring_err;
 
 	bp->tx_nr_rings_per_tc = bp->tx_nr_rings;
-	if (bnxt_rfs_supported(bp) && bnxt_rfs_capable(bp)) {
-		bp->flags |= BNXT_FLAG_RFS;
-		bp->dev->features |= NETIF_F_NTUPLE;
-	}
+
+	bnxt_set_dflt_rfs(bp);
+
 init_dflt_ring_err:
 	bnxt_ulp_irq_restart(bp, rc);
 	return rc;