This reverts commit 19110cfbb34d4af0cdfe14cd243f3b09dc95b013.
This reverts commit 4110e02eb45ea447ec6f5459c9934de0a273fb91.
This reverts commit d3604515c9eda464a92e8e67aae82dfe07fe3c98.
Commit 19110cfbb34d ("e1000e: Separate signaling for link check/link up")
changed what happens to the link status when there is an error which
happens after "get_link_status = false" in the copper check_for_link
callbacks. Previously, such an error would be ignored and the link
considered up. After that commit, any error implies that the link is down.
Revert commit 19110cfbb34d ("e1000e: Separate signaling for link check/link
up") and its followups. After reverting, the race condition described in
the log of commit 19110cfbb34d is reintroduced. It may still be triggered
by LSC events but this should keep the link down in case the link is
electrically unstable, as discussed. The race may no longer be
triggered by RXO events because commit 4aea7a5c5e94 ("e1000e: Avoid
receiver overrun interrupt bursts") restored reading icr in the Other
handler.
Link: https://lkml.org/lkml/2018/3/1/789
Signed-off-by: Benjamin Poirier <[email protected]>
---
drivers/net/ethernet/intel/e1000e/ich8lan.c | 13 ++++---------
drivers/net/ethernet/intel/e1000e/mac.c | 13 ++++---------
drivers/net/ethernet/intel/e1000e/netdev.c | 2 +-
3 files changed, 9 insertions(+), 19 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index ff308b05d68c..d6d4ed7acf03 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -1367,9 +1367,6 @@ static s32 e1000_disable_ulp_lpt_lp(struct e1000_hw *hw, bool force)
* Checks to see of the link status of the hardware has changed. If a
* change in link status has been detected, then we read the PHY registers
* to get the current speed/duplex if link exists.
- *
- * Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link
- * up).
**/
static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
{
@@ -1385,7 +1382,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
* Change or Rx Sequence Error interrupt.
*/
if (!mac->get_link_status)
- return 1;
+ return 0;
/* First we want to see if the MII Status Register reports
* link. If so, then we want to get the current speed/duplex
@@ -1602,7 +1599,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
* we have already determined whether we have link or not.
*/
if (!mac->autoneg)
- return 1;
+ return -E1000_ERR_CONFIG;
/* Auto-Neg is enabled. Auto Speed Detection takes care
* of MAC speed/duplex configuration. So we only need to
@@ -1616,12 +1613,10 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
* different link partner.
*/
ret_val = e1000e_config_fc_after_link_up(hw);
- if (ret_val) {
+ if (ret_val)
e_dbg("Error configuring flow control\n");
- return ret_val;
- }
- return 1;
+ return ret_val;
}
static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter)
diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c
index db735644b312..b322011ec282 100644
--- a/drivers/net/ethernet/intel/e1000e/mac.c
+++ b/drivers/net/ethernet/intel/e1000e/mac.c
@@ -410,9 +410,6 @@ void e1000e_clear_hw_cntrs_base(struct e1000_hw *hw)
* Checks to see of the link status of the hardware has changed. If a
* change in link status has been detected, then we read the PHY registers
* to get the current speed/duplex if link exists.
- *
- * Returns a negative error code (-E1000_ERR_*) or 0 (link down) or 1 (link
- * up).
**/
s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
{
@@ -426,7 +423,7 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
* Change or Rx Sequence Error interrupt.
*/
if (!mac->get_link_status)
- return 1;
+ return 0;
/* First we want to see if the MII Status Register reports
* link. If so, then we want to get the current speed/duplex
@@ -450,7 +447,7 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
* we have already determined whether we have link or not.
*/
if (!mac->autoneg)
- return 1;
+ return -E1000_ERR_CONFIG;
/* Auto-Neg is enabled. Auto Speed Detection takes care
* of MAC speed/duplex configuration. So we only need to
@@ -464,12 +461,10 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
* different link partner.
*/
ret_val = e1000e_config_fc_after_link_up(hw);
- if (ret_val) {
+ if (ret_val)
e_dbg("Error configuring flow control\n");
- return ret_val;
- }
- return 1;
+ return ret_val;
}
/**
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 9fd4050a91ca..8a3aa85b159c 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5090,7 +5090,7 @@ static bool e1000e_has_link(struct e1000_adapter *adapter)
case e1000_media_type_copper:
if (hw->mac.get_link_status) {
ret_val = hw->mac.ops.check_for_link(hw);
- link_active = ret_val > 0;
+ link_active = !hw->mac.get_link_status;
} else {
link_active = true;
}
--
2.16.2
Alex reported the following race condition:
/* link goes up... interrupt... schedule watchdog */
\ e1000_watchdog_task
\ e1000e_has_link
\ hw->mac.ops.check_for_link() === e1000e_check_for_copper_link
\ e1000e_phy_has_link_generic(..., &link)
link = true
/* link goes down... interrupt */
\ e1000_msix_other
hw->mac.get_link_status = true
/* link is up */
mac->get_link_status = false
link_active = true
/* link_active is true, wrongly, and stays so because
* get_link_status is false */
Avoid this problem by making sure that we don't set get_link_status = false
after having checked the link.
It seems this problem has been present since the introduction of e1000e.
Link: https://lkml.org/lkml/2018/1/29/338
Reported-by: Alexander Duyck <[email protected]>
Signed-off-by: Benjamin Poirier <[email protected]>
---
drivers/net/ethernet/intel/e1000e/ich8lan.c | 31 ++++++++++++++++-------------
drivers/net/ethernet/intel/e1000e/mac.c | 14 ++++++-------
2 files changed, 24 insertions(+), 21 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/ich8lan.c b/drivers/net/ethernet/intel/e1000e/ich8lan.c
index d6d4ed7acf03..1dddfb7b2de6 100644
--- a/drivers/net/ethernet/intel/e1000e/ich8lan.c
+++ b/drivers/net/ethernet/intel/e1000e/ich8lan.c
@@ -1383,6 +1383,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
*/
if (!mac->get_link_status)
return 0;
+ mac->get_link_status = false;
/* First we want to see if the MII Status Register reports
* link. If so, then we want to get the current speed/duplex
@@ -1390,12 +1391,12 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
*/
ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link);
if (ret_val)
- return ret_val;
+ goto out;
if (hw->mac.type == e1000_pchlan) {
ret_val = e1000_k1_gig_workaround_hv(hw, link);
if (ret_val)
- return ret_val;
+ goto out;
}
/* When connected at 10Mbps half-duplex, some parts are excessively
@@ -1428,7 +1429,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
ret_val = hw->phy.ops.acquire(hw);
if (ret_val)
- return ret_val;
+ goto out;
if (hw->mac.type == e1000_pch2lan)
emi_addr = I82579_RX_CONFIG;
@@ -1450,7 +1451,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
hw->phy.ops.release(hw);
if (ret_val)
- return ret_val;
+ goto out;
if (hw->mac.type >= e1000_pch_spt) {
u16 data;
@@ -1459,14 +1460,14 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
if (speed == SPEED_1000) {
ret_val = hw->phy.ops.acquire(hw);
if (ret_val)
- return ret_val;
+ goto out;
ret_val = e1e_rphy_locked(hw,
PHY_REG(776, 20),
&data);
if (ret_val) {
hw->phy.ops.release(hw);
- return ret_val;
+ goto out;
}
ptr_gap = (data & (0x3FF << 2)) >> 2;
@@ -1480,18 +1481,18 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
}
hw->phy.ops.release(hw);
if (ret_val)
- return ret_val;
+ goto out;
} else {
ret_val = hw->phy.ops.acquire(hw);
if (ret_val)
- return ret_val;
+ goto out;
ret_val = e1e_wphy_locked(hw,
PHY_REG(776, 20),
0xC023);
hw->phy.ops.release(hw);
if (ret_val)
- return ret_val;
+ goto out;
}
}
@@ -1518,7 +1519,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
(hw->adapter->pdev->device == E1000_DEV_ID_PCH_I218_V3)) {
ret_val = e1000_k1_workaround_lpt_lp(hw, link);
if (ret_val)
- return ret_val;
+ goto out;
}
if (hw->mac.type >= e1000_pch_lpt) {
/* Set platform power management values for
@@ -1526,7 +1527,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
*/
ret_val = e1000_platform_pm_pch_lpt(hw, link);
if (ret_val)
- return ret_val;
+ goto out;
}
/* Clear link partner's EEE ability */
@@ -1549,9 +1550,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
}
if (!link)
- return 0; /* No link detected */
-
- mac->get_link_status = false;
+ goto out;
switch (hw->mac.type) {
case e1000_pch2lan:
@@ -1617,6 +1616,10 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
e_dbg("Error configuring flow control\n");
return ret_val;
+
+out:
+ mac->get_link_status = true;
+ return ret_val;
}
static s32 e1000_get_variants_ich8lan(struct e1000_adapter *adapter)
diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c
index b322011ec282..5bdc3a2d4fd7 100644
--- a/drivers/net/ethernet/intel/e1000e/mac.c
+++ b/drivers/net/ethernet/intel/e1000e/mac.c
@@ -424,19 +424,15 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
*/
if (!mac->get_link_status)
return 0;
+ mac->get_link_status = false;
/* First we want to see if the MII Status Register reports
* link. If so, then we want to get the current speed/duplex
* of the PHY.
*/
ret_val = e1000e_phy_has_link_generic(hw, 1, 0, &link);
- if (ret_val)
- return ret_val;
-
- if (!link)
- return 0; /* No link detected */
-
- mac->get_link_status = false;
+ if (ret_val || !link)
+ goto out;
/* Check if there was DownShift, must be checked
* immediately after link-up
@@ -465,6 +461,10 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
e_dbg("Error configuring flow control\n");
return ret_val;
+
+out:
+ mac->get_link_status = true;
+ return ret_val;
}
/**
--
2.16.2
On Mon, Mar 5, 2018 at 5:55 PM, Benjamin Poirier <[email protected]> wrote:
> This reverts commit 19110cfbb34d4af0cdfe14cd243f3b09dc95b013.
> This reverts commit 4110e02eb45ea447ec6f5459c9934de0a273fb91.
> This reverts commit d3604515c9eda464a92e8e67aae82dfe07fe3c98.
>
> Commit 19110cfbb34d ("e1000e: Separate signaling for link check/link up")
> changed what happens to the link status when there is an error which
> happens after "get_link_status = false" in the copper check_for_link
> callbacks. Previously, such an error would be ignored and the link
> considered up. After that commit, any error implies that the link is down.
>
> Revert commit 19110cfbb34d ("e1000e: Separate signaling for link check/link
> up") and its followups. After reverting, the race condition described in
> the log of commit 19110cfbb34d is reintroduced. It may still be triggered
> by LSC events but this should keep the link down in case the link is
> electrically unstable, as discussed. The race may no longer be
> triggered by RXO events because commit 4aea7a5c5e94 ("e1000e: Avoid
> receiver overrun interrupt bursts") restored reading icr in the Other
> handler.
>
> Link: https://lkml.org/lkml/2018/3/1/789
> Signed-off-by: Benjamin Poirier <[email protected]>
Personally I am not a fan of the !mac->autoneg causing us to return an
error, but that is how the code was before and the error return code
will be ignored anyway.
Thanks for doing all this.
Acked-by: Alexander Duyck <[email protected]>
On Mon, Mar 5, 2018 at 5:55 PM, Benjamin Poirier <[email protected]> wrote:
> Alex reported the following race condition:
>
> /* link goes up... interrupt... schedule watchdog */
> \ e1000_watchdog_task
> \ e1000e_has_link
> \ hw->mac.ops.check_for_link() === e1000e_check_for_copper_link
> \ e1000e_phy_has_link_generic(..., &link)
> link = true
>
> /* link goes down... interrupt */
> \ e1000_msix_other
> hw->mac.get_link_status = true
>
> /* link is up */
> mac->get_link_status = false
>
> link_active = true
> /* link_active is true, wrongly, and stays so because
> * get_link_status is false */
>
> Avoid this problem by making sure that we don't set get_link_status = false
> after having checked the link.
>
> It seems this problem has been present since the introduction of e1000e.
>
> Link: https://lkml.org/lkml/2018/1/29/338
> Reported-by: Alexander Duyck <[email protected]>
> Signed-off-by: Benjamin Poirier <[email protected]>
Looks good. Thanks.
Acked-by: Alexander Duyck <[email protected]>
> From: Intel-wired-lan [mailto:[email protected]] On
> Behalf Of Benjamin Poirier
> Sent: Monday, March 5, 2018 5:56 PM
> To: Kirsher, Jeffrey T <[email protected]>
> Cc: [email protected]; [email protected]; linux-
> [email protected]; Lennart Sorensen <[email protected]>
> Subject: [Intel-wired-lan] [PATCH 1/2] Revert "e1000e: Separate signaling for
> link check/link up"
>
> This reverts commit 19110cfbb34d4af0cdfe14cd243f3b09dc95b013.
> This reverts commit 4110e02eb45ea447ec6f5459c9934de0a273fb91.
> This reverts commit d3604515c9eda464a92e8e67aae82dfe07fe3c98.
>
> Commit 19110cfbb34d ("e1000e: Separate signaling for link check/link up")
> changed what happens to the link status when there is an error which
> happens after "get_link_status = false" in the copper check_for_link
> callbacks. Previously, such an error would be ignored and the link
> considered up. After that commit, any error implies that the link is down.
>
> Revert commit 19110cfbb34d ("e1000e: Separate signaling for link check/link
> up") and its followups. After reverting, the race condition described in
> the log of commit 19110cfbb34d is reintroduced. It may still be triggered
> by LSC events but this should keep the link down in case the link is
> electrically unstable, as discussed. The race may no longer be
> triggered by RXO events because commit 4aea7a5c5e94 ("e1000e: Avoid
> receiver overrun interrupt bursts") restored reading icr in the Other
> handler.
>
> Link: https://lkml.org/lkml/2018/3/1/789
> Signed-off-by: Benjamin Poirier <[email protected]>
> ---
> drivers/net/ethernet/intel/e1000e/ich8lan.c | 13 ++++---------
> drivers/net/ethernet/intel/e1000e/mac.c | 13 ++++---------
> drivers/net/ethernet/intel/e1000e/netdev.c | 2 +-
> 3 files changed, 9 insertions(+), 19 deletions(-)
>
Tested-by: Aaron Brown <[email protected]>
> From: [email protected] [mailto:netdev-
> [email protected]] On Behalf Of Benjamin Poirier
> Sent: Monday, March 5, 2018 5:56 PM
> To: Kirsher, Jeffrey T <[email protected]>
> Cc: Alexander Duyck <[email protected]>; Lennart Sorensen
> <[email protected]>; [email protected];
> [email protected]; [email protected]
> Subject: [PATCH 2/2] e1000e: Fix link check race condition
>
> Alex reported the following race condition:
>
> /* link goes up... interrupt... schedule watchdog */
> \ e1000_watchdog_task
> \ e1000e_has_link
> \ hw->mac.ops.check_for_link() ===
> e1000e_check_for_copper_link
> \ e1000e_phy_has_link_generic(..., &link)
> link = true
>
> /* link goes down... interrupt */
> \ e1000_msix_other
> hw->mac.get_link_status =
> true
>
> /* link is up */
> mac->get_link_status = false
>
> link_active = true
> /* link_active is true, wrongly, and stays so because
> * get_link_status is false */
>
> Avoid this problem by making sure that we don't set get_link_status = false
> after having checked the link.
>
> It seems this problem has been present since the introduction of e1000e.
>
> Link: https://lkml.org/lkml/2018/1/29/338
> Reported-by: Alexander Duyck <[email protected]>
> Signed-off-by: Benjamin Poirier <[email protected]>
> ---
> drivers/net/ethernet/intel/e1000e/ich8lan.c | 31 ++++++++++++++++-------
> ------
> drivers/net/ethernet/intel/e1000e/mac.c | 14 ++++++-------
> 2 files changed, 24 insertions(+), 21 deletions(-)
Tested-by: Aaron Brown <[email protected]>