RE: [RFC Patch net-next v1 5/9] r8169: add support for msix

Javen
2026-04-27T06:41:33Z

>On 20.04.2026 04:19, javen wrote:
>> From: Javen Xu <javen_xu@realsil.com.cn>
>>
>> This patch add support for msix. But we still use MSI here. And we
>> force nvecs to 1. We will modify it in rss patch.
>
>This description is wrong. Also as of today r8169 supports MSIX.
>Reason likely is that you're copying code from vendor driver.
>
>>
>> Signed-off-by: Javen Xu <javen_xu@realsil.com.cn>
>> ---
>> drivers/net/ethernet/realtek/r8169_main.c | 162
>> ++++++++++++++++++++--
>> 1 file changed, 151 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/realtek/r8169_main.c
>> b/drivers/net/ethernet/realtek/r8169_main.c
>> index 52e690eba644..7d493342ab4b 100644
>> --- a/drivers/net/ethernet/realtek/r8169_main.c
>> +++ b/drivers/net/ethernet/realtek/r8169_main.c
>> @@ -1764,26 +1764,40 @@ static u32 rtl_get_events(struct
>> rtl8169_private *tp)
>>
>> static void rtl_ack_events(struct rtl8169_private *tp, u32 bits) {
>> - if (rtl_is_8125(tp))
>> + if (rtl_is_8125(tp)) {
>> RTL_W32(tp, IntrStatus_8125, bits);
>> - else
>> + if (tp->features & RTL_FEATURE_MSIX) {
>> + RTL_W32(tp, ISR_V2_8125, 0xffffffff);
>> + RTL_W32(tp, ISR_V4_L2_8125, 0xffffffff);
>> + }
>> + } else {
>> RTL_W16(tp, IntrStatus, bits);
>> + }
>> }
>>
>> static void rtl_irq_disable(struct rtl8169_private *tp) {
>> - if (rtl_is_8125(tp))
>> + if (rtl_is_8125(tp)) {
>> RTL_W32(tp, IntrMask_8125, 0);
>> - else
>> + if (tp->features & RTL_FEATURE_MSIX) {
>> + RTL_W32(tp, IMR_V2_CLEAR_REG_8125, 0xffffffff);
>> + RTL_W32(tp, IMR_V4_L2_CLEAR_REG_8125, 0xffffffff);
>> + }
>> + } else {
>> RTL_W16(tp, IntrMask, 0);
>> + }
>> }
>>
>> static void rtl_irq_enable(struct rtl8169_private *tp) {
>> - if (rtl_is_8125(tp))
>> - RTL_W32(tp, IntrMask_8125, tp->irq_mask);
>> - else
>> + if (rtl_is_8125(tp)) {
>> + if (tp->features & RTL_FEATURE_MSIX)
>> + RTL_W32(tp, IMR_V2_SET_REG_8125, tp->irq_mask);
>> + else
>> + RTL_W32(tp, IntrMask_8125, tp->irq_mask);
>> + } else {
>> RTL_W16(tp, IntrMask, tp->irq_mask);
>> + }
>> }
>>
>> static void rtl8169_irq_mask_and_ack(struct rtl8169_private *tp) @@
>> -2894,6 +2908,10 @@ static void rtl_software_parameter_initialize(struct
>rtl8169_private *tp)
>> tp->InitRxDescType = RX_DESC_RING_TYPE_DEAFULT;
>> tp->HwCurrIsrVer = tp->HwSuppIsrVer;
>>
>> + /* This just force nvecs, and will be remove in the following patch*/
>> + tp->min_irq_nvecs = 1;
>> + tp->max_irq_nvecs = 1;
>> +
>> rtl_setup_mqs_reg(tp);
>> rtl_set_ring_size(tp, NUM_RX_DESC, NUM_TX_DESC); } @@ -5321,6
>> +5339,44 @@ static void rtl8169_free_irq(struct rtl8169_private *tp)
>> }
>> }
>>
>> +static void rtl8169_disable_hw_interrupt_msix(struct rtl8169_private
>> +*tp, int message_id) {
>> + RTL_W32(tp, IMR_V2_CLEAR_REG_8125, BIT(message_id)); }
>> +
>> +static void rtl8169_clear_hw_isr(struct rtl8169_private *tp, int
>> +message_id) {
>> + RTL_W32(tp, ISR_V2_8125, BIT(message_id)); }
>> +
>> +static void rtl8169_enable_hw_interrupt_msix(struct rtl8169_private
>> +*tp, int message_id) {
>> + RTL_W32(tp, IMR_V2_SET_REG_8125, BIT(message_id)); }
>> +
>> +static irqreturn_t rtl8169_interrupt_msix(int irq, void
>> +*dev_instance) {
>> + struct rtl8169_napi *napi = dev_instance;
>> + struct rtl8169_private *tp = napi->priv;
>> + int message_id = napi->index;
>> +
>> + rtl8169_disable_hw_interrupt_msix(tp, message_id);
>> +
>> + rtl8169_clear_hw_isr(tp, message_id);
>> +
>> + if (message_id == MSIX_ID_V4_LINKCHG) {
>> + phy_mac_interrupt(tp->phydev);
>> + rtl8169_enable_hw_interrupt_msix(tp, message_id);
>> + return IRQ_HANDLED;
>> + }
>> +
>> + tp->recheck_desc_ownbit = true;
>> +
>> + napi_schedule(&napi->napi);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> static int rtl8169_request_irq(struct rtl8169_private *tp) {
>> struct net_device *dev = tp->dev; @@ -5331,10 +5387,14 @@ static
>> int rtl8169_request_irq(struct rtl8169_private *tp)
>>
>> for (int i = 0; i < tp->irq_nvecs; i++) {
>> irq = &tp->irq_tbl[i];
>> + if (tp->features & RTL_FEATURE_MSIX && tp->HwCurrIsrVer > 1)
>> + irq->handler = rtl8169_interrupt_msix;
>> + else
>> + irq->handler = rtl8169_interrupt;
>>
>> napi = &tp->r8169napi[i];
>> snprintf(irq->name, len, "%s-%d", dev->name, i);
>> - rc = pci_request_irq(tp->pci_dev, i, rtl8169_interrupt, NULL, napi,
>irq->name);
>> + rc = pci_request_irq(tp->pci_dev, i, irq->handler, NULL,
>> + napi, irq->name);
>>
>> if (rc)
>> break;
>> @@ -5786,10 +5846,18 @@ static const struct net_device_ops
>> rtl_netdev_ops = {
>>
>> static void rtl_set_irq_mask(struct rtl8169_private *tp) {
>> - tp->irq_mask = RxOK | RxErr | TxOK | TxErr | LinkChg;
>> + if (tp->features & RTL_FEATURE_MSIX) {
>> + tp->irq_mask = ISRIMR_V6_LINKCHG;
>> + for (int i = 0; i < tp->num_tx_rings; i++)
>> + tp->irq_mask |= ISRIMR_V6_TOK_Q0 << i;
>> + for (int i = 0; i < tp->num_rx_rings; i++)
>> + tp->irq_mask |= ISRIMR_V6_ROK_Q0 << i;
>> + } else {
>> + tp->irq_mask = RxOK | RxErr | TxOK | TxErr | LinkChg;
>>
>> - if (tp->mac_version <= RTL_GIGA_MAC_VER_06)
>> - tp->irq_mask |= SYSErr | RxFIFOOver;
>> + if (tp->mac_version <= RTL_GIGA_MAC_VER_06)
>> + tp->irq_mask |= SYSErr | RxFIFOOver;
>> + }
>> }
>>
>> static int rtl_alloc_irq(struct rtl8169_private *tp) @@ -5817,6
>> +5885,18 @@ static int rtl_alloc_irq(struct rtl8169_private *tp)
>> if (nvecs < 0)
>> nvecs = pci_alloc_irq_vectors(pdev, 1, 1,
>> PCI_IRQ_ALL_TYPES);
>>
>> + tp->features &= ~(RTL_FEATURE_MSIX | RTL_FEATURE_MSI);
>> +
>> + if (nvecs > 0) {
>> + tp->irq_nvecs = nvecs;
>> + tp->irq = pci_irq_vector(pdev, 0);
>> + if (nvecs > 1)
>> + tp->features |= RTL_FEATURE_MSIX;
>> + else if (pci_dev_msi_enabled(pdev))
>> + tp->features |= RTL_FEATURE_MSI;
>> + return 0;
>
>Such feature flags, especially for MSI/MSIX, are ugly.
>Why don't you leave the interrupt type selection to PCI core?
>This needs at least an explanation.

I completely agree that it is misleading and ugly.
The reason why I used tp-> features here is that I want to distinguish new interrupt mapping and old interrupt mapping. For RTL8127 with rss enabled, 8 rx queues refer to interrupt 0-7. For other chip with rss disabled, all tx/rx queues share the same interrupt. The specific differences are in function rtl8169_request_irq().
And I will rename the flag more appropriately to indicate the mapping method.

>
>> + }
>> +
>> tp->irq = pdev->irq;
>> tp->irq_nvecs = 1;
>>
>> @@ -6087,6 +6167,52 @@ static bool rtl_aspm_is_safe(struct
>rtl8169_private *tp)
>> return false;
>> }
>>
>> +static int rtl8169_poll_msix_rx(struct napi_struct *napi, int budget)
>> +{
>> + struct rtl8169_napi *r8169_napi = container_of(napi, struct rtl8169_napi,
>napi);
>> + struct rtl8169_private *tp = r8169_napi->priv;
>> + struct net_device *dev = tp->dev;
>> + const int message_id = r8169_napi->index;
>> + int work_done = 0;
>> +
>> + if (message_id < tp->num_rx_rings)
>> + work_done += rtl_rx(dev, tp, &tp->rx_ring[message_id],
>> + budget);
>> +
>> + if (work_done < budget && napi_complete_done(napi, work_done))
>> + rtl8169_enable_hw_interrupt_msix(tp, message_id);
>> +
>> + return work_done;
>> +}
>> +
>> +static int rtl8169_poll_msix_tx(struct napi_struct *napi, int budget)
>> +{
>> + struct rtl8169_napi *r8169_napi = container_of(napi, struct rtl8169_napi,
>napi);
>> + struct rtl8169_private *tp = r8169_napi->priv;
>> + struct net_device *dev = tp->dev;
>> + unsigned int work_done = 0;
>> + const int message_id = r8169_napi->index;
>> + int tx_ring_idx = message_id - 8;
>> +
>> + if (tx_ring_idx >= 0 && tx_ring_idx < tp->num_tx_rings)
>> + work_done += rtl_tx(dev, tp, &tp->tx_ring[tx_ring_idx],
>> + budget);
>> +
>> + if (work_done < budget && napi_complete_done(napi, work_done))
>> + rtl8169_enable_hw_interrupt_msix(tp, message_id);
>> +
>> + return work_done;
>> +}
>> +
>> +static int rtl8169_poll_msix_other(struct napi_struct *napi, int
>> +budget) {
>> + struct rtl8169_napi *r8169_napi = container_of(napi, struct rtl8169_napi,
>napi);
>> + struct rtl8169_private *tp = r8169_napi->priv;
>> + const int message_id = r8169_napi->index;
>> +
>> + napi_complete_done(napi, budget);
>> + rtl8169_enable_hw_interrupt_msix(tp, message_id);
>> +
>> + return 1;
>> +}
>>
>> static void r8169_init_napi(struct rtl8169_private *tp) { @@ -6095,6
>> +6221,20 @@ static void r8169_init_napi(struct rtl8169_private *tp)
>> int (*poll)(struct napi_struct *napi, int budget);
>>
>> poll = rtl8169_poll;
>> + if (tp->features & RTL_FEATURE_MSIX) {
>> + switch (tp->HwCurrIsrVer) {
>> + case 6:
>> + if (i < R8127_MAX_RX_QUEUES)
>> + poll = rtl8169_poll_msix_rx;
>> + else if (i > 7 && i < 16)
>> + poll = rtl8169_poll_msix_tx;
>> + else
>> + poll = rtl8169_poll_msix_other;
>> + break;
>> + default:
>> + break;
>> + }
>> + }
>> netif_napi_add(tp->dev, &r8169napi->napi, poll);
>> r8169napi->priv = tp;
>> r8169napi->index = i;