Re: [RFC Patch net-next v1 5/9] r8169: add support for msix
From: Heiner Kallweit
Date: Sat Apr 25 2026 - 18:14:30 EST
On 20.04.2026 04:19, javen wrote:
> From: Javen Xu <javen_xu@xxxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxx>
> ---
> 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.
> + }
> +
> 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;