Re: [RTnet-developers] [PATCH 6/6] e1000e: enable MSI again.

[Jan K. <jan...@si...>]

On 2011-10-06 22:35, Arnout Vandecappelle (Essensium/Mind) wrote:
> From: "Arnout Vandecappelle (Essensium/Mind)" <ar...@mi...>
> 
> e1000_test_msi(), which is a workaround for malfunctioning PCIe chipsets,
> is not included.  It is assumed the IntMode module parameter will be used
> if required.

MSI-X is usable under RT as well (see rt-igb changes) and should
generally be preferred over legacy MSI, e.g. due to lower hardware
latencies or separation of config and tx/rx interrupts - the former may
be realized as normal Linux IRQs when lucky.

Jan

> 
> Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <ar...@mi...>
> ---
>  drivers/experimental/e1000e/netdev.c |   35 ++++++++++++++++++++++++++-------
>  drivers/experimental/e1000e/param.c  |    4 +-
>  2 files changed, 29 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/experimental/e1000e/netdev.c b/drivers/experimental/e1000e/netdev.c
> index d005956..7bc606b 100644
> --- a/drivers/experimental/e1000e/netdev.c
> +++ b/drivers/experimental/e1000e/netdev.c
> @@ -1419,14 +1419,16 @@ static void e1000_configure_msix(struct e1000_adapter *adapter)
>  	ew32(CTRL_EXT, ctrl_ext);
>  	e1e_flush();
>  }
> +#endif
>  
>  void e1000e_reset_interrupt_capability(struct e1000_adapter *adapter)
>  {
> -	if (adapter->msix_entries) {
> -		pci_disable_msix(adapter->pdev);
> -		kfree(adapter->msix_entries);
> -		adapter->msix_entries = NULL;
> -	} else if (adapter->flags & FLAG_MSI_ENABLED) {
> +//	if (adapter->msix_entries) {
> +//		pci_disable_msix(adapter->pdev);
> +//		kfree(adapter->msix_entries);
> +//		adapter->msix_entries = NULL;
> +//	} else 
> +	if (adapter->flags & FLAG_MSI_ENABLED) {
>  		pci_disable_msi(adapter->pdev);
>  		adapter->flags &= ~FLAG_MSI_ENABLED;
>  	}
> @@ -1442,11 +1444,12 @@ void e1000e_reset_interrupt_capability(struct e1000_adapter *adapter)
>   **/
>  void e1000e_set_interrupt_capability(struct e1000_adapter *adapter)
>  {
> -	int err;
> -	int numvecs, i;
> +//	int err;
> +//	int numvecs, i;
>  
>  
>  	switch (adapter->int_mode) {
> +#ifdef DISABLED_FOR_RTNET
>  	case E1000E_INT_MODE_MSIX:
>  		if (adapter->flags & FLAG_HAS_MSIX) {
>  			numvecs = 3; /* RxQ0, TxQ0 and other */
> @@ -1470,6 +1473,7 @@ void e1000e_set_interrupt_capability(struct e1000_adapter *adapter)
>  		}
>  		adapter->int_mode = E1000E_INT_MODE_MSI;
>  		/* Fall through */
> +#endif
>  	case E1000E_INT_MODE_MSI:
>  		if (!pci_enable_msi(adapter->pdev)) {
>  			adapter->flags |= FLAG_MSI_ENABLED;
> @@ -1487,6 +1491,7 @@ void e1000e_set_interrupt_capability(struct e1000_adapter *adapter)
>  	return;
>  }
>  
> +#ifdef DISABLED_FOR_RTNET
>  /**
>   * e1000_request_msix - Initialize MSI-X interrupts
>   *
> @@ -1549,6 +1554,16 @@ static int e1000_request_irq(struct e1000_adapter *adapter)
>  
>  	rt_stack_connect(netdev, &STACK_manager);
>  
> +	if (adapter->flags & FLAG_MSI_ENABLED) {
> +		err = rtdm_irq_request(&adapter->irq_handle, adapter->pdev->irq,
> +				       &e1000_intr, 0, netdev->name, netdev);
> +		if (!err)
> +			return err;
> +
> +		/* fall back to legacy interrupt */
> +		e1000e_reset_interrupt_capability(adapter);
> +		adapter->int_mode = E1000E_INT_MODE_LEGACY;
> +	}
>  	err = rtdm_irq_request(&adapter->irq_handle, adapter->pdev->irq,
>  			       &e1000_intr, RTDM_IRQTYPE_SHARED, netdev->name, netdev);
>  	if (err)
> @@ -2884,6 +2899,8 @@ static int __devinit e1000_sw_init(struct e1000_adapter *adapter)
>  	adapter->max_frame_size = netdev->mtu + ETH_HLEN + ETH_FCS_LEN;
>  	adapter->min_frame_size = ETH_ZLEN + ETH_FCS_LEN;
>  
> +	e1000e_set_interrupt_capability(adapter);
> +
>  	if (rtskb_pool_init(&adapter->skb_pool, 16) < 16)
>  	{
>  		rtskb_pool_release(&adapter->skb_pool);
> @@ -4393,7 +4410,7 @@ static int __e1000_shutdown(struct pci_dev *pdev, bool *enable_wake)
>  		e1000e_down(adapter);
>  		e1000_free_irq(adapter);
>  	}
> -//	e1000e_reset_interrupt_capability(adapter);
> +	e1000e_reset_interrupt_capability(adapter);
>  
>  	retval = pci_save_state(pdev);
>  	if (retval)
> @@ -5186,6 +5203,8 @@ static void __devexit e1000_remove(struct pci_dev *pdev)
>  	 */
>  	e1000_release_hw_control(adapter);
>  
> +	e1000e_reset_interrupt_capability(adapter);
> +
>  	rt_unregister_rtnetdev(netdev);
>  
>  	if (!e1000_check_reset_block(&adapter->hw))
> diff --git a/drivers/experimental/e1000e/param.c b/drivers/experimental/e1000e/param.c
> index a57ddb8..09d5e60 100644
> --- a/drivers/experimental/e1000e/param.c
> +++ b/drivers/experimental/e1000e/param.c
> @@ -424,8 +424,8 @@ void __devinit e1000e_check_options(struct e1000_adapter *adapter)
>  		struct e1000_option opt = {
>  			.type = range_option,
>  			.name = "Interrupt Mode",
> -			.err  = "defaulting to 2 (MSI-X)",
> -			.def  = E1000E_INT_MODE_LEGACY, //E1000E_INT_MODE_MSIX,
> +			.err  = "defaulting to 1 (MSI)",
> +			.def  = E1000E_INT_MODE_MSI,
>  			.arg  = { .r = { .min = MIN_INTMODE,
>  					 .max = MAX_INTMODE } }
>  		};

-- 
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