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Message-Id: <1485330909-12037-3-git-send-email-michael.chan@broadcom.com>
Date: Wed, 25 Jan 2017 02:55:08 -0500
From: Michael Chan <michael.chan@...adcom.com>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org
Subject: [PATCH net 2/3] bnxt_en: Fix RTNL lock usage on bnxt_update_link().
bnxt_update_link() is called from multiple code paths. Most callers,
such as open, ethtool, already hold RTNL. Only the caller bnxt_sp_task()
does not. So it is a bug to take RTNL inside bnxt_update_link().
Fix it by removing the RTNL inside bnxt_update_link(). The function
now expects the caller to always hold RTNL.
In bnxt_sp_task(), call bnxt_rtnl_lock_sp() before calling
bnxt_update_link(). We also need to move the call to the end of
bnxt_sp_task() since it will be clearing the BNXT_STATE_IN_SP_TASK bit.
Signed-off-by: Michael Chan <michael.chan@...adcom.com>
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 37 +++++++++++++++----------------
1 file changed, 18 insertions(+), 19 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 30d7d64..69b0fce 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -5314,17 +5314,12 @@ static int bnxt_update_link(struct bnxt *bp, bool chng_link_state)
if ((link_info->support_auto_speeds | diff) !=
link_info->support_auto_speeds) {
/* An advertised speed is no longer supported, so we need to
- * update the advertisement settings. See bnxt_reset() for
- * comments about the rtnl_lock() sequence below.
+ * update the advertisement settings. Caller holds RTNL
+ * so we can modify link settings.
*/
- clear_bit(BNXT_STATE_IN_SP_TASK, &bp->state);
- rtnl_lock();
link_info->advertising = link_info->support_auto_speeds;
- if (test_bit(BNXT_STATE_OPEN, &bp->state) &&
- (link_info->autoneg & BNXT_AUTONEG_SPEED))
+ if (link_info->autoneg & BNXT_AUTONEG_SPEED)
bnxt_hwrm_set_link_setting(bp, true, false);
- set_bit(BNXT_STATE_IN_SP_TASK, &bp->state);
- rtnl_unlock();
}
return 0;
}
@@ -6231,7 +6226,6 @@ static void bnxt_reset(struct bnxt *bp, bool silent)
static void bnxt_sp_task(struct work_struct *work)
{
struct bnxt *bp = container_of(work, struct bnxt, sp_task);
- int rc;
set_bit(BNXT_STATE_IN_SP_TASK, &bp->state);
smp_mb__after_atomic();
@@ -6245,16 +6239,6 @@ static void bnxt_sp_task(struct work_struct *work)
if (test_and_clear_bit(BNXT_RX_NTP_FLTR_SP_EVENT, &bp->sp_event))
bnxt_cfg_ntp_filters(bp);
- if (test_and_clear_bit(BNXT_LINK_CHNG_SP_EVENT, &bp->sp_event)) {
- if (test_and_clear_bit(BNXT_LINK_SPEED_CHNG_SP_EVENT,
- &bp->sp_event))
- bnxt_hwrm_phy_qcaps(bp);
-
- rc = bnxt_update_link(bp, true);
- if (rc)
- netdev_err(bp->dev, "SP task can't update link (rc: %x)\n",
- rc);
- }
if (test_and_clear_bit(BNXT_HWRM_EXEC_FWD_REQ_SP_EVENT, &bp->sp_event))
bnxt_hwrm_exec_fwd_req(bp);
if (test_and_clear_bit(BNXT_VXLAN_ADD_PORT_SP_EVENT, &bp->sp_event)) {
@@ -6284,6 +6268,21 @@ static void bnxt_sp_task(struct work_struct *work)
/* These functions below will clear BNXT_STATE_IN_SP_TASK. They
* must be the last functions to be called before exiting.
*/
+ if (test_and_clear_bit(BNXT_LINK_CHNG_SP_EVENT, &bp->sp_event)) {
+ int rc = 0;
+
+ if (test_and_clear_bit(BNXT_LINK_SPEED_CHNG_SP_EVENT,
+ &bp->sp_event))
+ bnxt_hwrm_phy_qcaps(bp);
+
+ bnxt_rtnl_lock_sp(bp);
+ if (test_bit(BNXT_STATE_OPEN, &bp->state))
+ rc = bnxt_update_link(bp, true);
+ bnxt_rtnl_unlock_sp(bp);
+ if (rc)
+ netdev_err(bp->dev, "SP task can't update link (rc: %x)\n",
+ rc);
+ }
if (test_and_clear_bit(BNXT_RESET_TASK_SP_EVENT, &bp->sp_event))
bnxt_reset(bp, false);
--
1.8.3.1
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