On 12.01.2022 20:11, Robert Hancock wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> The GEM controllers on ZynqMP were missing some initialization steps which
> are required in some cases when using SGMII mode, which uses the PS-GTR
> transceivers managed by the phy-zynqmp driver.
>
> The GEM core appears to need a hardware-level reset in order to work
> properly in SGMII mode in cases where the GT reference clock was not
> present at initial power-on. This can be done using a reset mapped to
> the zynqmp-reset driver in the device tree.
>
> Also, when in SGMII mode, the GEM driver needs to ensure the PHY is
> initialized and powered on when it is initializing.
>
> Signed-off-by: Robert Hancock <robert.hancock@xxxxxxxxxx>
> ---
> drivers/net/ethernet/cadence/macb_main.c | 47 +++++++++++++++++++++++-
> 1 file changed, 46 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
> index a363da928e8b..65b0360c487a 100644
> --- a/drivers/net/ethernet/cadence/macb_main.c
> +++ b/drivers/net/ethernet/cadence/macb_main.c
> @@ -34,7 +34,9 @@
> #include <linux/udp.h>
> #include <linux/tcp.h>
> #include <linux/iopoll.h>
> +#include <linux/phy/phy.h>
> #include <linux/pm_runtime.h>
> +#include <linux/reset.h>
> #include "macb.h"
>
> /* This structure is only used for MACB on SiFive FU540 devices */
> @@ -4455,6 +4457,49 @@ static int fu540_c000_init(struct platform_device *pdev)
> return macb_init(pdev);
> }
>
> +static int zynqmp_init(struct platform_device *pdev)
> +{
> + struct net_device *dev = platform_get_drvdata(pdev);
> + struct macb *bp = netdev_priv(dev);
> + int ret;
> +
> + /* Fully reset GEM controller at hardware level using zynqmp-reset driver,
> + * if mapped in device tree.
> + */
> + ret = device_reset(&pdev->dev);
> + if (ret) {
> + dev_err_probe(&pdev->dev, ret, "failed to reset controller");
> + return ret;
If using old device trees this will fail, right? If yes, you should take
care this code will also work with old device trees.
Thank you,
Claudiu Beznea
> + }
> +
> + if (bp->phy_interface == PHY_INTERFACE_MODE_SGMII) {
> + /* Ensure PS-GTR PHY device used in SGMII mode is ready */
> + struct phy *sgmii_phy = devm_phy_get(&pdev->dev, "sgmii-phy");
> +
> + if (IS_ERR(sgmii_phy)) {
> + ret = PTR_ERR(sgmii_phy);
> + dev_err_probe(&pdev->dev, ret,
> + "failed to get PS-GTR PHY\n");
> + return ret;
> + }
> +
> + ret = phy_init(sgmii_phy);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to init PS-GTR PHY: %d\n",
> + ret);
> + return ret;
> + }
> +
> + ret = phy_power_on(sgmii_phy);
> + if (ret) {
> + dev_err(&pdev->dev, "failed to power on PS-GTR PHY: %d\n",
> + ret);
> + return ret;
> + }
> + }
> + return macb_init(pdev);
> +}
> +
> static const struct macb_usrio_config sama7g5_usrio = {
> .mii = 0,
> .rmii = 1,
> @@ -4550,7 +4595,7 @@ static const struct macb_config zynqmp_config = {
> MACB_CAPS_GEM_HAS_PTP | MACB_CAPS_BD_RD_PREFETCH,
> .dma_burst_length = 16,
> .clk_init = macb_clk_init,
> - .init = macb_init,
> + .init = zynqmp_init,
> .jumbo_max_len = 10240,
> .usrio = &macb_default_usrio,
> };
> --
> 2.31.1
>
