Re: [PATCH 1/4] net: ethernet: ti: am65-cpsw: Fix set channel operation

From: Roger Quadros
Date: Thu Nov 17 2022 - 04:39:01 EST




On 16/11/2022 18:49, Roger Quadros wrote:
> The set channel operation "ethtool -L tx <n>" broke with
> the recent suspend/resume changes.
>
> Revert back to original driver behaviour of not freeing
> the TX/RX IRQs at am65_cpsw_nuss_common_stop(). We will
> now free them only on .suspend() as we need to release
> the DMA channels (as DMA looses context) and re-acquiring
> them on .resume() may not necessarily give us the same
> IRQs.
>
> Introduce am65_cpsw_nuss_remove_rx_chns() which is similar
> to am65_cpsw_nuss_remove_tx_chns() and invoke them both in
> .suspend().
>
> At .resume() call am65_cpsw_nuss_init_rx/tx_chns() to
> acquire the DMA channels.
>
> To as IRQs need to be requested after knowing the IRQ
> numbers, move am65_cpsw_nuss_ndev_add_tx_napi() call to
> am65_cpsw_nuss_init_tx_chns().
>
> Also fixes the below warning during suspend/resume on multi
> CPU system.
>
> [ 67.347684] ------------[ cut here ]------------
> [ 67.347700] Unbalanced enable for IRQ 119
> [ 67.347726] WARNING: CPU: 0 PID: 1080 at kernel/irq/manage.c:781 __enable_irq+0x4c/0x80
> [ 67.347754] Modules linked in: wlcore_sdio wl18xx wlcore mac80211 libarc4 cfg80211 rfkill crct10dif_ce sch_fq_codel ipv6
> [ 67.347803] CPU: 0 PID: 1080 Comm: rtcwake Not tainted 6.1.0-rc4-00023-gc826e5480732-dirty #203
> [ 67.347812] Hardware name: Texas Instruments AM625 (DT)
> [ 67.347818] pstate: 400000c5 (nZcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> [ 67.347829] pc : __enable_irq+0x4c/0x80
> [ 67.347838] lr : __enable_irq+0x4c/0x80
> [ 67.347846] sp : ffff80000999ba00
> [ 67.347850] x29: ffff80000999ba00 x28: ffff0000011c1c80 x27: 0000000000000000
> [ 67.347863] x26: 00000000000001f4 x25: ffff000001058358 x24: ffff000001059080
> [ 67.347876] x23: ffff000001058080 x22: ffff000001060000 x21: 0000000000000077
> [ 67.347888] x20: ffff0000011c1c80 x19: ffff000001429600 x18: 0000000000000001
> [ 67.347900] x17: 0000000000000080 x16: fffffc000176e008 x15: ffff0000011c21b0
> [ 67.347913] x14: 0000000000000000 x13: 3931312051524920 x12: 726f6620656c6261
> [ 67.347925] x11: 656820747563205b x10: 000000000000000a x9 : ffff80000999ba00
> [ 67.347938] x8 : ffff800009121068 x7 : ffff80000999b810 x6 : 00000000fffff17f
> [ 67.347950] x5 : ffff00007fb99b18 x4 : 0000000000000000 x3 : 0000000000000027
> [ 67.347962] x2 : ffff00007fb99b20 x1 : 50dd48f7f19deb00 x0 : 0000000000000000
> [ 67.347975] Call trace:
> [ 67.347980] __enable_irq+0x4c/0x80
> [ 67.347989] enable_irq+0x4c/0xa0
> [ 67.347999] am65_cpsw_nuss_ndo_slave_open+0x4b0/0x568
> [ 67.348015] am65_cpsw_nuss_resume+0x68/0x160
> [ 67.348025] dpm_run_callback.isra.0+0x28/0x88
> [ 67.348040] device_resume+0x78/0x160
> [ 67.348050] dpm_resume+0xc0/0x1f8
> [ 67.348057] dpm_resume_end+0x18/0x30
> [ 67.348063] suspend_devices_and_enter+0x1cc/0x4e0
> [ 67.348075] pm_suspend+0x1f8/0x268
> [ 67.348084] state_store+0x8c/0x118
> [ 67.348092] kobj_attr_store+0x18/0x30
> [ 67.348104] sysfs_kf_write+0x44/0x58
> [ 67.348117] kernfs_fop_write_iter+0x118/0x1a8
> [ 67.348127] vfs_write+0x31c/0x418
> [ 67.348140] ksys_write+0x6c/0xf8
> [ 67.348150] __arm64_sys_write+0x1c/0x28
> [ 67.348160] invoke_syscall+0x44/0x108
> [ 67.348172] el0_svc_common.constprop.0+0x44/0xf0
> [ 67.348182] do_el0_svc+0x2c/0xc8
> [ 67.348191] el0_svc+0x2c/0x88
> [ 67.348201] el0t_64_sync_handler+0xb8/0xc0
> [ 67.348209] el0t_64_sync+0x18c/0x190
> [ 67.348218] ---[ end trace 0000000000000000 ]---
>
> Fixes: fd23df72f2be ("net: ethernet: ti: am65-cpsw: Add suspend/resume support")
> Signed-off-by: Roger Quadros <rogerq@xxxxxxxxxx>
> ---
> drivers/net/ethernet/ti/am65-cpsw-nuss.c | 160 +++++++++++++----------
> 1 file changed, 88 insertions(+), 72 deletions(-)
>
> diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> index f2e377524088..f8899ac5e249 100644
> --- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> +++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
> @@ -133,10 +133,7 @@
> NETIF_MSG_IFUP | NETIF_MSG_PROBE | NETIF_MSG_IFDOWN | \
> NETIF_MSG_RX_ERR | NETIF_MSG_TX_ERR)
>
> -static int am65_cpsw_nuss_init_tx_chns(struct am65_cpsw_common *common);
> -static int am65_cpsw_nuss_init_rx_chns(struct am65_cpsw_common *common);
> -static void am65_cpsw_nuss_free_tx_chns(struct am65_cpsw_common *common);
> -static void am65_cpsw_nuss_free_rx_chns(struct am65_cpsw_common *common);
> +static int am65_cpsw_nuss_ndev_add_tx_napi(struct am65_cpsw_common *common);
>
> static void am65_cpsw_port_set_sl_mac(struct am65_cpsw_port *slave,
> const u8 *dev_addr)
> @@ -379,20 +376,6 @@ static int am65_cpsw_nuss_common_open(struct am65_cpsw_common *common)
> if (common->usage_count)
> return 0;
>
> - /* init tx/rx channels */
> - ret = am65_cpsw_nuss_init_tx_chns(common);
> - if (ret) {
> - dev_err(common->dev, "init_tx_chns failed\n");
> - return ret;
> - }
> -
> - ret = am65_cpsw_nuss_init_rx_chns(common);
> - if (ret) {
> - dev_err(common->dev, "init_rx_chns failed\n");
> - am65_cpsw_nuss_free_tx_chns(common);
> - return ret;
> - }
> -
> /* Control register */
> writel(AM65_CPSW_CTL_P0_ENABLE | AM65_CPSW_CTL_P0_TX_CRC_REMOVE |
> AM65_CPSW_CTL_VLAN_AWARE | AM65_CPSW_CTL_P0_RX_PAD,
> @@ -453,8 +436,7 @@ static int am65_cpsw_nuss_common_open(struct am65_cpsw_common *common)
> GFP_KERNEL);
> if (!skb) {
> dev_err(common->dev, "cannot allocate skb\n");
> - ret = -ENOMEM;
> - goto err;
> + return -ENOMEM;
> }
>
> ret = am65_cpsw_nuss_rx_push(common, skb);
> @@ -463,7 +445,7 @@ static int am65_cpsw_nuss_common_open(struct am65_cpsw_common *common)
> "cannot submit skb to channel rx, error %d\n",
> ret);
> kfree_skb(skb);
> - goto err;
> + return ret;
> }
> kmemleak_not_leak(skb);
> }
> @@ -472,7 +454,7 @@ static int am65_cpsw_nuss_common_open(struct am65_cpsw_common *common)
> for (i = 0; i < common->tx_ch_num; i++) {
> ret = k3_udma_glue_enable_tx_chn(common->tx_chns[i].tx_chn);
> if (ret)
> - goto err;
> + return ret;
> napi_enable(&common->tx_chns[i].napi_tx);
> }
>
> @@ -484,12 +466,6 @@ static int am65_cpsw_nuss_common_open(struct am65_cpsw_common *common)
>
> dev_dbg(common->dev, "cpsw_nuss started\n");
> return 0;
> -
> -err:
> - am65_cpsw_nuss_free_tx_chns(common);
> - am65_cpsw_nuss_free_rx_chns(common);
> -
> - return ret;
> }
>
> static void am65_cpsw_nuss_tx_cleanup(void *data, dma_addr_t desc_dma);
> @@ -543,9 +519,6 @@ static int am65_cpsw_nuss_common_stop(struct am65_cpsw_common *common)
> writel(0, common->cpsw_base + AM65_CPSW_REG_CTL);
> writel(0, common->cpsw_base + AM65_CPSW_REG_STAT_PORT_EN);
>
> - am65_cpsw_nuss_free_tx_chns(common);
> - am65_cpsw_nuss_free_rx_chns(common);
> -
> dev_dbg(common->dev, "cpsw_nuss stopped\n");
> return 0;
> }
> @@ -597,9 +570,6 @@ static int am65_cpsw_nuss_ndo_slave_open(struct net_device *ndev)
> cpsw_sl_ctl_set(port->slave.mac_sl, CPSW_SL_CTL_CMD_IDLE);
>
> tmo = cpsw_sl_wait_for_idle(port->slave.mac_sl, 100);
> - dev_info(common->dev, "down msc_sl %08x tmo %d\n",
> - cpsw_sl_reg_read(port->slave.mac_sl, CPSW_SL_MACSTATUS), tmo);
> -

This produces the below warning. I'll change it to dev_dbg() instead of dropping it entirely.

drivers/net/ethernet/ti/am65-cpsw-nuss.c:562:13: warning: variable 'tmo' set but not used [-Wunused-but-set-variable]

> cpsw_sl_ctl_reset(port->slave.mac_sl);
>
> /* soft reset MAC */
> @@ -1548,9 +1518,9 @@ static void am65_cpsw_nuss_slave_disable_unused(struct am65_cpsw_port *port)
> cpsw_sl_ctl_reset(port->slave.mac_sl);
> }

<snip>

cheers,
-roger