Rohan G Thomas <rohan.g.thomas@xxxxxxxxx> writes:
> Enable Time Based Scheduling(TBS) support for Tx queues through the
> stmmac platform driver. For this a new per-queue tx-config property,
> tbs-enabled is added to the devicetree.
>
> Commit 7eadf57290ec ("net: stmmac: pci: Enable TBS on GMAC5 IPK PCI
> entry") enables similar support for the stmmac pci driver.
>
> Also add check whether TBS support is available for a Tx DMA channel
> before enabling TBS support for that Tx DMA channel.
>
> Signed-off-by: Rohan G Thomas <rohan.g.thomas@xxxxxxxxx>
> ---
> .../net/ethernet/stmicro/stmmac/stmmac_main.c | 25 +++++++++++++++----
> .../ethernet/stmicro/stmmac/stmmac_platform.c | 4 +++
> 2 files changed, 24 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 81b6f3ecdf92..7333f0640b3d 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -3773,12 +3773,18 @@ stmmac_setup_dma_desc(struct stmmac_priv *priv, unsigned int mtu)
> dma_conf->dma_rx_size = DMA_DEFAULT_RX_SIZE;
>
> /* Earlier check for TBS */
> - for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++) {
> - struct stmmac_tx_queue *tx_q = &dma_conf->tx_queue[chan];
> - int tbs_en = priv->plat->tx_queues_cfg[chan].tbs_en;
> + if (priv->dma_cap.tbssel) {
> + /* TBS is available only for tbs_ch_num of Tx DMA channels,
> + * starting from the highest Tx DMA channel.
> + */
> + chan = priv->dma_cap.number_tx_channel - priv->dma_cap.tbs_ch_num;
> + for (; chan < priv->plat->tx_queues_to_use; chan++) {
> + struct stmmac_tx_queue *tx_q = &dma_conf->tx_queue[chan];
> + int tbs_en = priv->plat->tx_queues_cfg[chan].tbs_en;
>
> - /* Setup per-TXQ tbs flag before TX descriptor alloc */
> - tx_q->tbs |= tbs_en ? STMMAC_TBS_AVAIL : 0;
> + /* Setup per-TXQ tbs flag before TX descriptor alloc */
> + tx_q->tbs |= tbs_en ? STMMAC_TBS_AVAIL : 0;
> + }
> }
>
> ret = alloc_dma_desc_resources(priv, dma_conf);
> @@ -7505,6 +7511,15 @@ int stmmac_dvr_probe(struct device *device,
> }
> }
>
> + /* If TBS feature is supported(i.e. tbssel is true), then at least 1 Tx
> + * DMA channel supports TBS. So if tbs_ch_num is 0 and tbssel is true,
> + * assume all Tx DMA channels support TBS. TBS_CH field, which gives
> + * number of Tx DMA channels with TBS support is only available only for
> + * DW xGMAC IP. For other DWMAC IPs all Tx DMA channels can support TBS.
The Ethernet QOS controllers found in various i.MX socs does not support
TBS on TX queue 0. I believe this patch would break the dwmac driver for
these platforms.
> + */
> + if (priv->dma_cap.tbssel && !priv->dma_cap.tbs_ch_num)
> + priv->dma_cap.tbs_ch_num = priv->dma_cap.number_tx_channel;
> +
> ndev->features |= ndev->hw_features | NETIF_F_HIGHDMA;
> ndev->watchdog_timeo = msecs_to_jiffies(watchdog);
> #ifdef STMMAC_VLAN_TAG_USED
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> index 843bd8804bfa..6c0191c84071 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> @@ -279,6 +279,10 @@ static int stmmac_mtl_setup(struct platform_device *pdev,
> plat->tx_queues_cfg[queue].coe_unsupported =
> of_property_read_bool(q_node, "snps,coe-unsupported");
>
> + /* Select TBS for supported queues */
> + plat->tx_queues_cfg[queue].tbs_en =
> + of_property_read_bool(q_node, "snps,tbs-enabled");
> +
> queue++;
> }
> if (queue != plat->tx_queues_to_use) {
/Esben
