From de856a5b802cf030c8e242e98df3bc88446a4ea1 Mon Sep 17 00:00:00 2001 Message-ID: In-Reply-To: References: From: Lorenzo Bianconi Date: Fri, 20 Mar 2026 11:09:40 +0100 Subject: [PATCH 07/13] net: airoha: Do not stop GDM port if it is shared Theoretically, in the current codebase, two independent net_devices can be connected to the same GDM port so we need to check the GDM port is not used by any other running net_device before setting the forward configuration to FE_PSE_PORT_DROP. Moreover, always set in GDM_LONG_LEN_MASK field of REG_GDM_LEN_CFG register the maximum MTU of all running net_devices connected to the same GDM port. Tested-by: Xuegang Lu Signed-off-by: Lorenzo Bianconi --- drivers/net/ethernet/airoha/airoha_eth.c | 59 +++++++++++++++++++----- drivers/net/ethernet/airoha/airoha_eth.h | 1 + 2 files changed, 48 insertions(+), 12 deletions(-) --- a/drivers/net/ethernet/airoha/airoha_eth.c +++ b/drivers/net/ethernet/airoha/airoha_eth.c @@ -1858,8 +1858,8 @@ static int airoha_dev_open(struct net_de int err, len = ETH_HLEN + netdev->mtu + ETH_FCS_LEN; struct airoha_gdm_dev *dev = netdev_priv(netdev); struct airoha_gdm_port *port = dev->port; + u32 cur_len, pse_port = FE_PSE_PORT_PPE1; struct airoha_qdma *qdma = dev->qdma; - u32 pse_port = FE_PSE_PORT_PPE1; #if defined(CONFIG_PCS_AIROHA) if (airhoa_is_phy_external(port)) { @@ -1887,10 +1887,20 @@ static int airoha_dev_open(struct net_de airoha_fe_clear(qdma->eth, REG_GDM_INGRESS_CFG(port->id), GDM_STAG_EN_MASK); - airoha_fe_rmw(qdma->eth, REG_GDM_LEN_CFG(port->id), - GDM_SHORT_LEN_MASK | GDM_LONG_LEN_MASK, - FIELD_PREP(GDM_SHORT_LEN_MASK, 60) | - FIELD_PREP(GDM_LONG_LEN_MASK, len)); + cur_len = airoha_fe_get(qdma->eth, REG_GDM_LEN_CFG(port->id), + GDM_LONG_LEN_MASK); + if (!port->users || len > cur_len) { + /* Opening a sibling net_device with a larger MTU updates the + * MTU of already running devices. This is required to allow + * multiple net_devices with different MTUs to share the same + * GDM port. + */ + airoha_fe_rmw(qdma->eth, REG_GDM_LEN_CFG(port->id), + GDM_SHORT_LEN_MASK | GDM_LONG_LEN_MASK, + FIELD_PREP(GDM_SHORT_LEN_MASK, 60) | + FIELD_PREP(GDM_LONG_LEN_MASK, len)); + } + port->users++; airoha_qdma_set(qdma, REG_QDMA_GLOBAL_CFG, GLOBAL_CFG_TX_DMA_EN_MASK | @@ -1906,6 +1916,30 @@ static int airoha_dev_open(struct net_de return 0; } +static void airoha_set_port_mtu(struct airoha_eth *eth, + struct airoha_gdm_port *port) +{ + u32 len = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(port->devs); i++) { + struct airoha_gdm_dev *dev = port->devs[i]; + struct net_device *netdev; + + if (!dev) + continue; + + netdev = dev->dev; + if (netif_running(netdev)) + len = max_t(u32, len, netdev->mtu); + } + len += ETH_HLEN + ETH_FCS_LEN; + + airoha_fe_rmw(eth, REG_GDM_LEN_CFG(port->id), + GDM_LONG_LEN_MASK, + FIELD_PREP(GDM_LONG_LEN_MASK, len)); +} + static int airoha_dev_stop(struct net_device *netdev) { struct airoha_gdm_dev *dev = netdev_priv(netdev); @@ -1918,8 +1952,12 @@ static int airoha_dev_stop(struct net_de for (i = 0; i < netdev->num_tx_queues; i++) netdev_tx_reset_subqueue(netdev, i); - airoha_set_gdm_port_fwd_cfg(qdma->eth, REG_GDM_FWD_CFG(port->id), - FE_PSE_PORT_DROP); + if (--port->users) + airoha_set_port_mtu(dev->eth, port); + else + airoha_set_gdm_port_fwd_cfg(qdma->eth, + REG_GDM_FWD_CFG(port->id), + FE_PSE_PORT_DROP); if (atomic_dec_and_test(&qdma->users)) { airoha_qdma_clear(qdma, REG_QDMA_GLOBAL_CFG, @@ -2081,13 +2119,10 @@ static int airoha_dev_change_mtu(struct { struct airoha_gdm_dev *dev = netdev_priv(netdev); struct airoha_gdm_port *port = dev->port; - u32 len = ETH_HLEN + mtu + ETH_FCS_LEN; - struct airoha_eth *eth = dev->eth; - airoha_fe_rmw(eth, REG_GDM_LEN_CFG(port->id), - GDM_LONG_LEN_MASK, - FIELD_PREP(GDM_LONG_LEN_MASK, len)); WRITE_ONCE(netdev->mtu, mtu); + if (port->users) + airoha_set_port_mtu(dev->eth, port); return 0; } --- a/drivers/net/ethernet/airoha/airoha_eth.h +++ b/drivers/net/ethernet/airoha/airoha_eth.h @@ -572,6 +572,7 @@ struct airoha_gdm_dev { struct airoha_gdm_port { struct airoha_gdm_dev *devs[AIROHA_MAX_NUM_GDM_DEVS]; int id; + int users; struct airoha_hw_stats stats;