[PATCH net-queue 1/3] Partial revert "e1000e: Avoid receiver overrun interrupt bursts"

[PATCH net-queue 1/3] Partial revert "e1000e: Avoid receiver overrun interrupt bursts"

[Benjamin Poirier]

This partially reverts commit 4aea7a5c5e940c1723add439f4088844cd26196d.

We keep the fix for the first part of the problem (1) described in the log
of that commit, that is to read ICR in the other interrupt handler. We
remove the fix for the second part of the problem (2), Other interrupt
throttling.

Bursts of "Other" interrupts may once again occur during rxo (receive
overflow) traffic conditions. This is deemed acceptable in the interest of
avoiding unforeseen fallout from changes that are not strictly necessary.
As discussed, the e1000e driver should be in "maintenance mode".

Link: https://www.spinics.net/lists/netdev/msg480675.html
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
---
 drivers/net/ethernet/intel/e1000e/netdev.c | 16 ++--------------
 1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 153ad406c65e..3b36efa6228d 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -1915,21 +1915,10 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 	struct e1000_hw *hw = &adapter->hw;
 	u32 icr;
-	bool enable = true;
 
 	icr = er32(ICR);
 	ew32(ICR, E1000_ICR_OTHER);
 
-	if (icr & E1000_ICR_RXO) {
-		ew32(ICR, E1000_ICR_RXO);
-		enable = false;
-		/* napi poll will re-enable Other, make sure it runs */
-		if (napi_schedule_prep(&adapter->napi)) {
-			adapter->total_rx_bytes = 0;
-			adapter->total_rx_packets = 0;
-			__napi_schedule(&adapter->napi);
-		}
-	}
 	if (icr & E1000_ICR_LSC) {
 		ew32(ICR, E1000_ICR_LSC);
 		hw->mac.get_link_status = true;
@@ -1938,7 +1927,7 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
 			mod_timer(&adapter->watchdog_timer, jiffies + 1);
 	}
 
-	if (enable && !test_bit(__E1000_DOWN, &adapter->state))
+	if (!test_bit(__E1000_DOWN, &adapter->state))
 		ew32(IMS, E1000_IMS_OTHER);
 
 	return IRQ_HANDLED;
@@ -2708,8 +2697,7 @@ static int e1000e_poll(struct napi_struct *napi, int weight)
 		napi_complete_done(napi, work_done);
 		if (!test_bit(__E1000_DOWN, &adapter->state)) {
 			if (adapter->msix_entries)
-				ew32(IMS, adapter->rx_ring->ims_val |
-				     E1000_IMS_OTHER);
+				ew32(IMS, adapter->rx_ring->ims_val);
 			else
 				e1000_irq_enable(adapter);
 		}
-- 
2.16.1

[PATCH net-queue 2/3] e1000e: Fix queue interrupt re-raising in Other interrupt.

[Benjamin Poirier]

restores the ICS write for rx/tx queue interrupts which was present before
commit 16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt",
v4.5-rc1) but was not restored in commit 4aea7a5c5e94 ("e1000e: Avoid
receiver overrun interrupt bursts", v4.15-rc1).

This re-raises the queue interrupts in case the txq or rxq bits were set in
ICR and the Other interrupt handler read and cleared ICR before the queue
interrupt was raised.

Fixes: 4aea7a5c5e94 ("e1000e: Avoid receiver overrun interrupt bursts")
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
---
 drivers/net/ethernet/intel/e1000e/netdev.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 3b36efa6228d..2c9609bee2ae 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -1919,6 +1919,9 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
 	icr = er32(ICR);
 	ew32(ICR, E1000_ICR_OTHER);
 
+	if (icr & adapter->eiac_mask)
+		ew32(ICS, (icr & adapter->eiac_mask));
+
 	if (icr & E1000_ICR_LSC) {
 		ew32(ICR, E1000_ICR_LSC);
 		hw->mac.get_link_status = true;
-- 
2.16.1

[PATCH net-queue 3/3] e1000e: Avoid missed interrupts following ICR read.

[Benjamin Poirier]

The 82574 specification update errata 12 states that interrupts may be
missed if ICR is read while INT_ASSERTED is not set. Avoid that problem by
setting all bits related to events that can trigger the Other interrupt in
IMS.

The Other interrupt is raised for such events regardless of whether or not
they are set in IMS. However, only when they are set is the INT_ASSERTED
bit also set in ICR.

By doing this, we ensure that INT_ASSERTED is always set when we read ICR
in e1000_msix_other() and steer clear of the errata. This also ensures that
ICR will automatically be cleared on read, therefore we no longer need to
clear bits explicitly.

Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
---
 drivers/net/ethernet/intel/e1000e/defines.h | 21 ++++++++++++++++++++-
 drivers/net/ethernet/intel/e1000e/netdev.c  | 11 ++++-------
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/intel/e1000e/defines.h b/drivers/net/ethernet/intel/e1000e/defines.h
index afb7ebe20b24..824fd44e25f0 100644
--- a/drivers/net/ethernet/intel/e1000e/defines.h
+++ b/drivers/net/ethernet/intel/e1000e/defines.h
@@ -400,6 +400,10 @@
 #define E1000_ICR_RXDMT0        0x00000010 /* Rx desc min. threshold (0) */
 #define E1000_ICR_RXO           0x00000040 /* Receiver Overrun */
 #define E1000_ICR_RXT0          0x00000080 /* Rx timer intr (ring 0) */
+#define E1000_ICR_MDAC          0x00000200 /* MDIO Access Complete */
+#define E1000_ICR_SRPD          0x00010000 /* Small Receive Packet Detected */
+#define E1000_ICR_ACK           0x00020000 /* Receive ACK Frame Detected */
+#define E1000_ICR_MNG           0x00040000 /* Manageability Event Detected */
 #define E1000_ICR_ECCER         0x00400000 /* Uncorrectable ECC Error */
 /* If this bit asserted, the driver should claim the interrupt */
 #define E1000_ICR_INT_ASSERTED	0x80000000
@@ -407,7 +411,7 @@
 #define E1000_ICR_RXQ1          0x00200000 /* Rx Queue 1 Interrupt */
 #define E1000_ICR_TXQ0          0x00400000 /* Tx Queue 0 Interrupt */
 #define E1000_ICR_TXQ1          0x00800000 /* Tx Queue 1 Interrupt */
-#define E1000_ICR_OTHER         0x01000000 /* Other Interrupts */
+#define E1000_ICR_OTHER         0x01000000 /* Other Interrupt */
 
 /* PBA ECC Register */
 #define E1000_PBA_ECC_COUNTER_MASK  0xFFF00000 /* ECC counter mask */
@@ -431,12 +435,27 @@
 	E1000_IMS_RXSEQ  |    \
 	E1000_IMS_LSC)
 
+/* These are all of the events related to the OTHER interrupt.
+ */
+#define IMS_OTHER_MASK ( \
+	E1000_IMS_LSC  | \
+	E1000_IMS_RXO  | \
+	E1000_IMS_MDAC | \
+	E1000_IMS_SRPD | \
+	E1000_IMS_ACK  | \
+	E1000_IMS_MNG)
+
 /* Interrupt Mask Set */
 #define E1000_IMS_TXDW      E1000_ICR_TXDW      /* Transmit desc written back */
 #define E1000_IMS_LSC       E1000_ICR_LSC       /* Link Status Change */
 #define E1000_IMS_RXSEQ     E1000_ICR_RXSEQ     /* Rx sequence error */
 #define E1000_IMS_RXDMT0    E1000_ICR_RXDMT0    /* Rx desc min. threshold */
+#define E1000_IMS_RXO       E1000_ICR_RXO       /* Receiver Overrun */
 #define E1000_IMS_RXT0      E1000_ICR_RXT0      /* Rx timer intr */
+#define E1000_IMS_MDAC      E1000_ICR_MDAC      /* MDIO Access Complete */
+#define E1000_IMS_SRPD      E1000_ICR_SRPD      /* Small Receive Packet */
+#define E1000_IMS_ACK       E1000_ICR_ACK       /* Receive ACK Frame Detected */
+#define E1000_IMS_MNG       E1000_ICR_MNG       /* Manageability Event */
 #define E1000_IMS_ECCER     E1000_ICR_ECCER     /* Uncorrectable ECC Error */
 #define E1000_IMS_RXQ0      E1000_ICR_RXQ0      /* Rx Queue 0 Interrupt */
 #define E1000_IMS_RXQ1      E1000_ICR_RXQ1      /* Rx Queue 1 Interrupt */
diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 2c9609bee2ae..9fd4050a91ca 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -1914,16 +1914,12 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
 	struct net_device *netdev = data;
 	struct e1000_adapter *adapter = netdev_priv(netdev);
 	struct e1000_hw *hw = &adapter->hw;
-	u32 icr;
-
-	icr = er32(ICR);
-	ew32(ICR, E1000_ICR_OTHER);
+	u32 icr = er32(ICR);
 
 	if (icr & adapter->eiac_mask)
 		ew32(ICS, (icr & adapter->eiac_mask));
 
 	if (icr & E1000_ICR_LSC) {
-		ew32(ICR, E1000_ICR_LSC);
 		hw->mac.get_link_status = true;
 		/* guard against interrupt when we're going down */
 		if (!test_bit(__E1000_DOWN, &adapter->state))
@@ -1931,7 +1927,7 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
 	}
 
 	if (!test_bit(__E1000_DOWN, &adapter->state))
-		ew32(IMS, E1000_IMS_OTHER);
+		ew32(IMS, E1000_IMS_OTHER | IMS_OTHER_MASK);
 
 	return IRQ_HANDLED;
 }
@@ -2258,7 +2254,8 @@ static void e1000_irq_enable(struct e1000_adapter *adapter)
 
 	if (adapter->msix_entries) {
 		ew32(EIAC_82574, adapter->eiac_mask & E1000_EIAC_MASK_82574);
-		ew32(IMS, adapter->eiac_mask | E1000_IMS_OTHER | E1000_IMS_LSC);
+		ew32(IMS, adapter->eiac_mask | E1000_IMS_OTHER |
+		     IMS_OTHER_MASK);
 	} else if (hw->mac.type >= e1000_pch_lpt) {
 		ew32(IMS, IMS_ENABLE_MASK | E1000_IMS_ECCER);
 	} else {
-- 
2.16.1

Re: [PATCH net-queue 1/3] Partial revert "e1000e: Avoid receiver overrun interrupt bursts"

[Benjamin Poirier]

I forgot to mark it as such but this is v2 of the series originally
submitted in this thread:
https://lkml.org/lkml/2018/1/26/93

Changes since v1:
* series rebased to apply over "e1000e: Remove Other from EIAC."
  http://patchwork.ozlabs.org/patch/867833/
  This essentially removes patch 3/3 from the original series.
* dropped [PATCH 2/3] Revert "e1000e: Separate signaling for link
  check/link up". After Alex's feedback, I think that problem needs to
  be addressed differently and I will submit a separate patch for it.
* patch 1 was split into three parts. Instead of manually clearing OTHER
  via a write to icr as in v1, in v2 we make sure that INT_ASSERTED is
  always set via bits for all events related to the Other interrupt in
  IMS.

Benjamin Poirier (3):
  Partial revert "e1000e: Avoid receiver overrun interrupt bursts"
  e1000e: Fix queue interrupt re-raising in Other interrupt.
  e1000e: Avoid missed interrupts following ICR read.

 drivers/net/ethernet/intel/e1000e/defines.h | 21 ++++++++++++++++++-
 drivers/net/ethernet/intel/e1000e/netdev.c  | 32 +++++++++--------------------
 2 files changed, 30 insertions(+), 23 deletions(-)

On 2018/02/08 15:47, Benjamin Poirier wrote:
> This partially reverts commit 4aea7a5c5e940c1723add439f4088844cd26196d.
> 
> We keep the fix for the first part of the problem (1) described in the log
> of that commit, that is to read ICR in the other interrupt handler. We
> remove the fix for the second part of the problem (2), Other interrupt
> throttling.
> 
> Bursts of "Other" interrupts may once again occur during rxo (receive
> overflow) traffic conditions. This is deemed acceptable in the interest of
> avoiding unforeseen fallout from changes that are not strictly necessary.
> As discussed, the e1000e driver should be in "maintenance mode".
> 
> Link: https://www.spinics.net/lists/netdev/msg480675.html
> Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c | 16 ++--------------
>  1 file changed, 2 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index 153ad406c65e..3b36efa6228d 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -1915,21 +1915,10 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
>  	struct e1000_adapter *adapter = netdev_priv(netdev);
>  	struct e1000_hw *hw = &adapter->hw;
>  	u32 icr;
> -	bool enable = true;
>  
>  	icr = er32(ICR);
>  	ew32(ICR, E1000_ICR_OTHER);
>  
> -	if (icr & E1000_ICR_RXO) {
> -		ew32(ICR, E1000_ICR_RXO);
> -		enable = false;
> -		/* napi poll will re-enable Other, make sure it runs */
> -		if (napi_schedule_prep(&adapter->napi)) {
> -			adapter->total_rx_bytes = 0;
> -			adapter->total_rx_packets = 0;
> -			__napi_schedule(&adapter->napi);
> -		}
> -	}
>  	if (icr & E1000_ICR_LSC) {
>  		ew32(ICR, E1000_ICR_LSC);
>  		hw->mac.get_link_status = true;
> @@ -1938,7 +1927,7 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
>  			mod_timer(&adapter->watchdog_timer, jiffies + 1);
>  	}
>  
> -	if (enable && !test_bit(__E1000_DOWN, &adapter->state))
> +	if (!test_bit(__E1000_DOWN, &adapter->state))
>  		ew32(IMS, E1000_IMS_OTHER);
>  
>  	return IRQ_HANDLED;
> @@ -2708,8 +2697,7 @@ static int e1000e_poll(struct napi_struct *napi, int weight)
>  		napi_complete_done(napi, work_done);
>  		if (!test_bit(__E1000_DOWN, &adapter->state)) {
>  			if (adapter->msix_entries)
> -				ew32(IMS, adapter->rx_ring->ims_val |
> -				     E1000_IMS_OTHER);
> +				ew32(IMS, adapter->rx_ring->ims_val);
>  			else
>  				e1000_irq_enable(adapter);
>  		}
> -- 
> 2.16.1
> 

Re: [PATCH net-queue 1/3] Partial revert "e1000e: Avoid receiver overrun interrupt bursts"

[Alexander Duyck]

On Wed, Feb 7, 2018 at 10:47 PM, Benjamin Poirier <bpoirier@suse.com> wrote:
> This partially reverts commit 4aea7a5c5e940c1723add439f4088844cd26196d.
>
> We keep the fix for the first part of the problem (1) described in the log
> of that commit, that is to read ICR in the other interrupt handler. We
> remove the fix for the second part of the problem (2), Other interrupt
> throttling.
>
> Bursts of "Other" interrupts may once again occur during rxo (receive
> overflow) traffic conditions. This is deemed acceptable in the interest of
> avoiding unforeseen fallout from changes that are not strictly necessary.
> As discussed, the e1000e driver should be in "maintenance mode".
>
> Link: https://www.spinics.net/lists/netdev/msg480675.html
> Signed-off-by: Benjamin Poirier <bpoirier@suse.com>

Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>

> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c | 16 ++--------------
>  1 file changed, 2 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index 153ad406c65e..3b36efa6228d 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -1915,21 +1915,10 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
>         struct e1000_adapter *adapter = netdev_priv(netdev);
>         struct e1000_hw *hw = &adapter->hw;
>         u32 icr;
> -       bool enable = true;
>
>         icr = er32(ICR);
>         ew32(ICR, E1000_ICR_OTHER);
>
> -       if (icr & E1000_ICR_RXO) {
> -               ew32(ICR, E1000_ICR_RXO);
> -               enable = false;
> -               /* napi poll will re-enable Other, make sure it runs */
> -               if (napi_schedule_prep(&adapter->napi)) {
> -                       adapter->total_rx_bytes = 0;
> -                       adapter->total_rx_packets = 0;
> -                       __napi_schedule(&adapter->napi);
> -               }
> -       }
>         if (icr & E1000_ICR_LSC) {
>                 ew32(ICR, E1000_ICR_LSC);
>                 hw->mac.get_link_status = true;
> @@ -1938,7 +1927,7 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
>                         mod_timer(&adapter->watchdog_timer, jiffies + 1);
>         }
>
> -       if (enable && !test_bit(__E1000_DOWN, &adapter->state))
> +       if (!test_bit(__E1000_DOWN, &adapter->state))
>                 ew32(IMS, E1000_IMS_OTHER);
>
>         return IRQ_HANDLED;
> @@ -2708,8 +2697,7 @@ static int e1000e_poll(struct napi_struct *napi, int weight)
>                 napi_complete_done(napi, work_done);
>                 if (!test_bit(__E1000_DOWN, &adapter->state)) {
>                         if (adapter->msix_entries)
> -                               ew32(IMS, adapter->rx_ring->ims_val |
> -                                    E1000_IMS_OTHER);
> +                               ew32(IMS, adapter->rx_ring->ims_val);
>                         else
>                                 e1000_irq_enable(adapter);
>                 }
> --
> 2.16.1
>

Re: [PATCH net-queue 2/3] e1000e: Fix queue interrupt re-raising in Other interrupt.

[Alexander Duyck]

On Wed, Feb 7, 2018 at 10:47 PM, Benjamin Poirier <bpoirier@suse.com> wrote:
> restores the ICS write for rx/tx queue interrupts which was present before
> commit 16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt",
> v4.5-rc1) but was not restored in commit 4aea7a5c5e94 ("e1000e: Avoid
> receiver overrun interrupt bursts", v4.15-rc1).
>
> This re-raises the queue interrupts in case the txq or rxq bits were set in
> ICR and the Other interrupt handler read and cleared ICR before the queue
> interrupt was raised.
>
> Fixes: 4aea7a5c5e94 ("e1000e: Avoid receiver overrun interrupt bursts")
> Signed-off-by: Benjamin Poirier <bpoirier@suse.com>

Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>

> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index 3b36efa6228d..2c9609bee2ae 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -1919,6 +1919,9 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
>         icr = er32(ICR);
>         ew32(ICR, E1000_ICR_OTHER);
>
> +       if (icr & adapter->eiac_mask)
> +               ew32(ICS, (icr & adapter->eiac_mask));
> +
>         if (icr & E1000_ICR_LSC) {
>                 ew32(ICR, E1000_ICR_LSC);
>                 hw->mac.get_link_status = true;
> --
> 2.16.1
>

Re: [PATCH net-queue 3/3] e1000e: Avoid missed interrupts following ICR read.

[Alexander Duyck]

On Wed, Feb 7, 2018 at 10:47 PM, Benjamin Poirier <bpoirier@suse.com> wrote:
> The 82574 specification update errata 12 states that interrupts may be
> missed if ICR is read while INT_ASSERTED is not set. Avoid that problem by
> setting all bits related to events that can trigger the Other interrupt in
> IMS.
>
> The Other interrupt is raised for such events regardless of whether or not
> they are set in IMS. However, only when they are set is the INT_ASSERTED
> bit also set in ICR.
>
> By doing this, we ensure that INT_ASSERTED is always set when we read ICR
> in e1000_msix_other() and steer clear of the errata. This also ensures that
> ICR will automatically be cleared on read, therefore we no longer need to
> clear bits explicitly.
>
> Signed-off-by: Benjamin Poirier <bpoirier@suse.com>

Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>

> ---
>  drivers/net/ethernet/intel/e1000e/defines.h | 21 ++++++++++++++++++++-
>  drivers/net/ethernet/intel/e1000e/netdev.c  | 11 ++++-------
>  2 files changed, 24 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/e1000e/defines.h b/drivers/net/ethernet/intel/e1000e/defines.h
> index afb7ebe20b24..824fd44e25f0 100644
> --- a/drivers/net/ethernet/intel/e1000e/defines.h
> +++ b/drivers/net/ethernet/intel/e1000e/defines.h
> @@ -400,6 +400,10 @@
>  #define E1000_ICR_RXDMT0        0x00000010 /* Rx desc min. threshold (0) */
>  #define E1000_ICR_RXO           0x00000040 /* Receiver Overrun */
>  #define E1000_ICR_RXT0          0x00000080 /* Rx timer intr (ring 0) */
> +#define E1000_ICR_MDAC          0x00000200 /* MDIO Access Complete */
> +#define E1000_ICR_SRPD          0x00010000 /* Small Receive Packet Detected */
> +#define E1000_ICR_ACK           0x00020000 /* Receive ACK Frame Detected */
> +#define E1000_ICR_MNG           0x00040000 /* Manageability Event Detected */
>  #define E1000_ICR_ECCER         0x00400000 /* Uncorrectable ECC Error */
>  /* If this bit asserted, the driver should claim the interrupt */
>  #define E1000_ICR_INT_ASSERTED 0x80000000
> @@ -407,7 +411,7 @@
>  #define E1000_ICR_RXQ1          0x00200000 /* Rx Queue 1 Interrupt */
>  #define E1000_ICR_TXQ0          0x00400000 /* Tx Queue 0 Interrupt */
>  #define E1000_ICR_TXQ1          0x00800000 /* Tx Queue 1 Interrupt */
> -#define E1000_ICR_OTHER         0x01000000 /* Other Interrupts */
> +#define E1000_ICR_OTHER         0x01000000 /* Other Interrupt */
>
>  /* PBA ECC Register */
>  #define E1000_PBA_ECC_COUNTER_MASK  0xFFF00000 /* ECC counter mask */
> @@ -431,12 +435,27 @@
>         E1000_IMS_RXSEQ  |    \
>         E1000_IMS_LSC)
>
> +/* These are all of the events related to the OTHER interrupt.
> + */
> +#define IMS_OTHER_MASK ( \
> +       E1000_IMS_LSC  | \
> +       E1000_IMS_RXO  | \
> +       E1000_IMS_MDAC | \
> +       E1000_IMS_SRPD | \
> +       E1000_IMS_ACK  | \
> +       E1000_IMS_MNG)
> +
>  /* Interrupt Mask Set */
>  #define E1000_IMS_TXDW      E1000_ICR_TXDW      /* Transmit desc written back */
>  #define E1000_IMS_LSC       E1000_ICR_LSC       /* Link Status Change */
>  #define E1000_IMS_RXSEQ     E1000_ICR_RXSEQ     /* Rx sequence error */
>  #define E1000_IMS_RXDMT0    E1000_ICR_RXDMT0    /* Rx desc min. threshold */
> +#define E1000_IMS_RXO       E1000_ICR_RXO       /* Receiver Overrun */
>  #define E1000_IMS_RXT0      E1000_ICR_RXT0      /* Rx timer intr */
> +#define E1000_IMS_MDAC      E1000_ICR_MDAC      /* MDIO Access Complete */
> +#define E1000_IMS_SRPD      E1000_ICR_SRPD      /* Small Receive Packet */
> +#define E1000_IMS_ACK       E1000_ICR_ACK       /* Receive ACK Frame Detected */
> +#define E1000_IMS_MNG       E1000_ICR_MNG       /* Manageability Event */
>  #define E1000_IMS_ECCER     E1000_ICR_ECCER     /* Uncorrectable ECC Error */
>  #define E1000_IMS_RXQ0      E1000_ICR_RXQ0      /* Rx Queue 0 Interrupt */
>  #define E1000_IMS_RXQ1      E1000_ICR_RXQ1      /* Rx Queue 1 Interrupt */
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index 2c9609bee2ae..9fd4050a91ca 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -1914,16 +1914,12 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
>         struct net_device *netdev = data;
>         struct e1000_adapter *adapter = netdev_priv(netdev);
>         struct e1000_hw *hw = &adapter->hw;
> -       u32 icr;
> -
> -       icr = er32(ICR);
> -       ew32(ICR, E1000_ICR_OTHER);
> +       u32 icr = er32(ICR);
>
>         if (icr & adapter->eiac_mask)
>                 ew32(ICS, (icr & adapter->eiac_mask));
>
>         if (icr & E1000_ICR_LSC) {
> -               ew32(ICR, E1000_ICR_LSC);
>                 hw->mac.get_link_status = true;
>                 /* guard against interrupt when we're going down */
>                 if (!test_bit(__E1000_DOWN, &adapter->state))
> @@ -1931,7 +1927,7 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
>         }
>
>         if (!test_bit(__E1000_DOWN, &adapter->state))
> -               ew32(IMS, E1000_IMS_OTHER);
> +               ew32(IMS, E1000_IMS_OTHER | IMS_OTHER_MASK);
>
>         return IRQ_HANDLED;
>  }
> @@ -2258,7 +2254,8 @@ static void e1000_irq_enable(struct e1000_adapter *adapter)
>
>         if (adapter->msix_entries) {
>                 ew32(EIAC_82574, adapter->eiac_mask & E1000_EIAC_MASK_82574);
> -               ew32(IMS, adapter->eiac_mask | E1000_IMS_OTHER | E1000_IMS_LSC);
> +               ew32(IMS, adapter->eiac_mask | E1000_IMS_OTHER |
> +                    IMS_OTHER_MASK);
>         } else if (hw->mac.type >= e1000_pch_lpt) {
>                 ew32(IMS, IMS_ENABLE_MASK | E1000_IMS_ECCER);
>         } else {
> --
> 2.16.1
>

RE: [Intel-wired-lan] [PATCH net-queue 1/3] Partial revert "e1000e: Avoid receiver overrun interrupt bursts"

[Brown, Aaron F]

> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On
> Behalf Of Benjamin Poirier
> Sent: Wednesday, February 7, 2018 10:47 PM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>
> Cc: netdev@vger.kernel.org; intel-wired-lan@lists.osuosl.org; linux-
> kernel@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH net-queue 1/3] Partial revert "e1000e:
> Avoid receiver overrun interrupt bursts"
> 
> This partially reverts commit 4aea7a5c5e940c1723add439f4088844cd26196d.
> 
> We keep the fix for the first part of the problem (1) described in the log
> of that commit, that is to read ICR in the other interrupt handler. We
> remove the fix for the second part of the problem (2), Other interrupt
> throttling.
> 
> Bursts of "Other" interrupts may once again occur during rxo (receive
> overflow) traffic conditions. This is deemed acceptable in the interest of
> avoiding unforeseen fallout from changes that are not strictly necessary.
> As discussed, the e1000e driver should be in "maintenance mode".
> 
> Link: https://www.spinics.net/lists/netdev/msg480675.html
> Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c | 16 ++--------------
>  1 file changed, 2 insertions(+), 14 deletions(-)

Tested-by: Aaron Brown <aaron.f.brown@intel.com>

RE: [Intel-wired-lan] [PATCH net-queue 2/3] e1000e: Fix queue interrupt re-raising in Other interrupt.

[Brown, Aaron F]

> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On
> Behalf Of Benjamin Poirier
> Sent: Wednesday, February 7, 2018 10:47 PM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>
> Cc: netdev@vger.kernel.org; intel-wired-lan@lists.osuosl.org; linux-
> kernel@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH net-queue 2/3] e1000e: Fix queue
> interrupt re-raising in Other interrupt.
> 
> restores the ICS write for rx/tx queue interrupts which was present before
> commit 16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt",
> v4.5-rc1) but was not restored in commit 4aea7a5c5e94 ("e1000e: Avoid
> receiver overrun interrupt bursts", v4.15-rc1).
> 
> This re-raises the queue interrupts in case the txq or rxq bits were set in
> ICR and the Other interrupt handler read and cleared ICR before the queue
> interrupt was raised.
> 
> Fixes: 4aea7a5c5e94 ("e1000e: Avoid receiver overrun interrupt bursts")
> Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c | 3 +++
>  1 file changed, 3 insertions(+)

Tested-by: Aaron Brown <aaron.f.brown@intel.com>

RE: [Intel-wired-lan] [PATCH net-queue 3/3] e1000e: Avoid missed interrupts following ICR read.

[Brown, Aaron F]

> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On
> Behalf Of Benjamin Poirier
> Sent: Wednesday, February 7, 2018 10:47 PM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>
> Cc: netdev@vger.kernel.org; intel-wired-lan@lists.osuosl.org; linux-
> kernel@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH net-queue 3/3] e1000e: Avoid missed
> interrupts following ICR read.
> 
> The 82574 specification update errata 12 states that interrupts may be
> missed if ICR is read while INT_ASSERTED is not set. Avoid that problem by
> setting all bits related to events that can trigger the Other interrupt in
> IMS.
> 
> The Other interrupt is raised for such events regardless of whether or not
> they are set in IMS. However, only when they are set is the INT_ASSERTED
> bit also set in ICR.
> 
> By doing this, we ensure that INT_ASSERTED is always set when we read ICR
> in e1000_msix_other() and steer clear of the errata. This also ensures that
> ICR will automatically be cleared on read, therefore we no longer need to
> clear bits explicitly.
> 
> Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
> ---
>  drivers/net/ethernet/intel/e1000e/defines.h | 21
> ++++++++++++++++++++-
>  drivers/net/ethernet/intel/e1000e/netdev.c  | 11 ++++-------
>  2 files changed, 24 insertions(+), 8 deletions(-)
> 

Tested-by: Aaron Brown <aaron.f.brown@intel.com>