[SRU,Bionic,1/1] e1000e: Remove Other from EIAC

From: Benjamin Poirier <bpoirier@suse.com>

BugLink: http://bugs.launchpad.net/bugs/1764892

It was reported that emulated e1000e devices in vmware esxi 6.5 Build
7526125 do not link up after commit 4aea7a5c5e94 ("e1000e: Avoid receiver
overrun interrupt bursts", v4.15-rc1). Some tracing shows that after
e1000e_trigger_lsc() is called, ICR reads out as 0x0 in e1000_msix_other()
on emulated e1000e devices. In comparison, on real e1000e 82574 hardware,
icr=0x80000004 (_INT_ASSERTED | _LSC) in the same situation.

Some experimentation showed that this flaw in vmware e1000e emulation can
be worked around by not setting Other in EIAC. This is how it was before
16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt", v4.5-rc1).

Fixes: 4aea7a5c5e94 ("e1000e: Avoid receiver overrun interrupt bursts")
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit 745d0bd3af99ccc8c5f5822f808cd133eadad6ac)
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
---
 drivers/net/ethernet/intel/e1000e/netdev.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

On 04/27/18 20:31, Joseph Salisbury wrote:
> From: Benjamin Poirier <bpoirier@suse.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/1764892
> 
> It was reported that emulated e1000e devices in vmware esxi 6.5 Build
> 7526125 do not link up after commit 4aea7a5c5e94 ("e1000e: Avoid receiver
> overrun interrupt bursts", v4.15-rc1). Some tracing shows that after
> e1000e_trigger_lsc() is called, ICR reads out as 0x0 in e1000_msix_other()
> on emulated e1000e devices. In comparison, on real e1000e 82574 hardware,
> icr=0x80000004 (_INT_ASSERTED | _LSC) in the same situation.
> 
> Some experimentation showed that this flaw in vmware e1000e emulation can
> be worked around by not setting Other in EIAC. This is how it was before
> 16ecba59bc33 ("e1000e: Do not read ICR in Other interrupt", v4.5-rc1).
> 
> Fixes: 4aea7a5c5e94 ("e1000e: Avoid receiver overrun interrupt bursts")
> Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
> Tested-by: Aaron Brown <aaron.f.brown@intel.com>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
> (cherry picked from commit 745d0bd3af99ccc8c5f5822f808cd133eadad6ac)
> Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>

Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

Clean cherry-pick, fixes a regression and tested by the reporter.

Thanks,
Kleber

> ---
>  drivers/net/ethernet/intel/e1000e/netdev.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
> index 6103023..6758bda 100644
> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
> @@ -1918,6 +1918,8 @@ static irqreturn_t e1000_msix_other(int __always_unused irq, void *data)
>  	bool enable = true;
>  
>  	icr = er32(ICR);
> +	ew32(ICR, E1000_ICR_OTHER);
> +
>  	if (icr & E1000_ICR_RXO) {
>  		ew32(ICR, E1000_ICR_RXO);
>  		enable = false;
> @@ -2040,7 +2042,6 @@ static void e1000_configure_msix(struct e1000_adapter *adapter)
>  		       hw->hw_addr + E1000_EITR_82574(vector));
>  	else
>  		writel(1, hw->hw_addr + E1000_EITR_82574(vector));
> -	adapter->eiac_mask |= E1000_IMS_OTHER;
>  
>  	/* Cause Tx interrupts on every write back */
>  	ivar |= BIT(31);
> @@ -2265,7 +2266,7 @@ 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_LSC);
> +		ew32(IMS, adapter->eiac_mask | E1000_IMS_OTHER | E1000_IMS_LSC);
>  	} else if (hw->mac.type >= e1000_pch_lpt) {
>  		ew32(IMS, IMS_ENABLE_MASK | E1000_IMS_ECCER);
>  	} else {
>