MLK-22541 ahci: imx: ahci: imx: set the rx water mark to fix the gen3 link issue

- Refine the tx/rx impedance ratio setting.
- Set the RxWaterMark to fix the GEN3 link unstable issue on iMX8QM.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
(cherry picked from commit 13234ea070f3b0048c98b59200bb3ed85659d013)

diff --git a/drivers/ata/ahci_imx.c b/drivers/ata/ahci_imx.c
index 8a93a9f..8170006 100644 (file)
--- a/drivers/ata/ahci_imx.c
+++ b/drivers/ata/ahci_imx.c
@@ -59,7 +59,7 @@ enum {
        IMX8QM_SATA_PHY_REG09_TX_IMPED_RATIO            = 0x09,
        IMX8QM_SATA_PHY_REG10_TX_POST_CURSOR_RATIO      = 0x0a,
        IMX8QM_SATA_PHY_GEN1_TX_POST_CURSOR_RATIO       = 0x15,
-       IMX8QM_SATA_PHY_IMPED_RATIO_85OHM               = 0x6c,
+       IMX8QM_SATA_PHY_IMPED_RATIO_100OHM              = 0x5d,
        IMX8QM_SATA_PHY_REG22_TX_POST_CURSOR_RATIO      = 0x16,
        IMX8QM_SATA_PHY_GEN2_TX_POST_CURSOR_RATIO       = 0x00,
        IMX8QM_SATA_PHY_REG24_TX_AMP_RATIO_MARGIN0      = 0x18,
@@ -98,6 +98,9 @@ enum {
        IMX8QM_SATA_PP3CFG_COMWAKE_BURST_GAP            = 0x08 << 16,
        IMX8QM_SATA_PP3CFG_COMWAKE_BURST_GAP_MAX        = 0x0f << 8,
        IMX8QM_SATA_PP3CFG_COMWAKE_BURST_GAP_MIN        = 0x01 << 0,
+       IMX8QM_SATA_AHCI_VEND_PTC                       = 0xc8,
+       IMX8QM_SATA_AHCI_VEND_PTC_RXWM_MASK             = 0x7f,
+       IMX8QM_SATA_AHCI_VEND_PTC_RXWM                  = 0x29,
 
        IMX8QM_LPCG_PHYX2_PCLK0_MASK            = (0x3 << 16),
        IMX8QM_LPCG_PHYX2_PCLK1_MASK            = (0x3 << 20),
@@ -833,6 +836,12 @@ static int imx8_sata_enable(struct ahci_host_priv *hpriv)
                if (unlikely(reg != imxpriv->imped_ratio))
                        dev_info(dev, "Can't set PHY TX impedance ratio.\n");
 
+               /* RxWaterMark setting */
+               val = readl(hpriv->mmio + IMX8QM_SATA_AHCI_VEND_PTC);
+               val &= ~IMX8QM_SATA_AHCI_VEND_PTC_RXWM_MASK;
+               val |= IMX8QM_SATA_AHCI_VEND_PTC_RXWM;
+               writel(val, hpriv->mmio + IMX8QM_SATA_AHCI_VEND_PTC);
+
                /* Configure the tx_amplitude to pass the tests. */
                writeb(IMX8QM_SATA_PHY_TX_AMP_RATIO_MARGIN0, imxpriv->phy_base +
                                IMX8QM_SATA_PHY_REG24_TX_AMP_RATIO_MARGIN0);
@@ -1251,13 +1260,8 @@ static int imx8_sata_probe(struct device *dev, struct imx_ahci_priv *imxpriv)
        }
 
        if (of_property_read_u32(np, "fsl,phy-imp", &imxpriv->imped_ratio)) {
-               /*
-                * Regarding to the differnet Hw designs,
-                * Set the impedance ratio to 0x6c when 85OHM is used.
-                * Keep it to default value 0x80, when 100OHM is used.
-                */
                dev_info(dev, "phy impedance ratio is not specified.\n");
-               imxpriv->imped_ratio = IMX8QM_SATA_PHY_IMPED_RATIO_85OHM;
+               imxpriv->imped_ratio = IMX8QM_SATA_PHY_IMPED_RATIO_100OHM;
        }
        phy_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "phy");
        if (phy_res) {