[PATCH net-next v6 4/5] net: phy: mediatek: Extend 1G TX/RX link pulse time
From: Sky Huang
Date: Mon Jun 03 2024 - 08:21:54 EST
From: "SkyLake.Huang" <skylake.huang@xxxxxxxxxxxx>
We observe that some 10G devices' (mostly Marvell's chips inside) 1G
training time violates specification, which may last 2230ms and affect
later TX/RX link pulse time. This will invalidate MediaTek series
gigabit Ethernet PHYs' hardware auto downshift mechanism.
Without this patch, if someone is trying to use "4-wire" cable to
connect above devices, MediaTek' gigabit Ethernet PHYs may fail
to downshift to 100Mbps. (If partner 10G devices' downshift mechanism
stops at 1G)
This patch extends our 1G TX/RX link pulse time so that we can still
link up with those 10G devices.
Tested device:
- Netgear GS110EMX's 10G port (Marvell 88X3340P)
- QNAP QSW-M408-4C
Signed-off-by: SkyLake.Huang <skylake.huang@xxxxxxxxxxxx>
---
Changes in v3:
- Refactor mtk_gphy_cl22_read_status() with genphy_read_status().
Changes in v4:
1. Change extend_an_new_lp_cnt_limit()'s return type and all return values
2. Refactor comments in extend_an_new_lp_cnt_limit()
Changes in v6:
1. Add LP_DETECTED so extend_an_new_lp_cnt_limit() won't be called every
time we poll the PHY for its status. It'll be called only when cable is
plugged in and 1G training starts.
2. Call phy_read_paged() instead of calling phy_select_page() &
phy_restore_page() pair.
---
drivers/net/phy/mediatek/mtk-ge-soc.c | 2 +
drivers/net/phy/mediatek/mtk-ge.c | 5 +-
drivers/net/phy/mediatek/mtk-phy-lib.c | 90 ++++++++++++++++++++++++++
drivers/net/phy/mediatek/mtk.h | 21 ++++++
4 files changed, 114 insertions(+), 4 deletions(-)
diff --git a/drivers/net/phy/mediatek/mtk-ge-soc.c b/drivers/net/phy/mediatek/mtk-ge-soc.c
index e0bbf99..fac6121 100644
--- a/drivers/net/phy/mediatek/mtk-ge-soc.c
+++ b/drivers/net/phy/mediatek/mtk-ge-soc.c
@@ -1399,6 +1399,7 @@ static struct phy_driver mtk_socphy_driver[] = {
PHY_ID_MATCH_EXACT(MTK_GPHY_ID_MT7981),
.name = "MediaTek MT7981 PHY",
.config_init = mt798x_phy_config_init,
+ .read_status = mtk_gphy_cl22_read_status,
.config_intr = genphy_no_config_intr,
.handle_interrupt = genphy_handle_interrupt_no_ack,
.probe = mt7981_phy_probe,
@@ -1416,6 +1417,7 @@ static struct phy_driver mtk_socphy_driver[] = {
PHY_ID_MATCH_EXACT(MTK_GPHY_ID_MT7988),
.name = "MediaTek MT7988 PHY",
.config_init = mt798x_phy_config_init,
+ .read_status = mtk_gphy_cl22_read_status,
.config_intr = genphy_no_config_intr,
.handle_interrupt = genphy_handle_interrupt_no_ack,
.probe = mt7988_phy_probe,
diff --git a/drivers/net/phy/mediatek/mtk-ge.c b/drivers/net/phy/mediatek/mtk-ge.c
index bd907c1..ce5786d 100644
--- a/drivers/net/phy/mediatek/mtk-ge.c
+++ b/drivers/net/phy/mediatek/mtk-ge.c
@@ -8,10 +8,6 @@
#define MTK_GPHY_ID_MT7530 0x03a29412
#define MTK_GPHY_ID_MT7531 0x03a29441
-#define MTK_PHY_PAGE_EXTENDED_1 0x0001
-#define MTK_PHY_AUX_CTRL_AND_STATUS 0x14
-#define MTK_PHY_ENABLE_DOWNSHIFT BIT(4)
-
#define MTK_PHY_PAGE_EXTENDED_2 0x0002
#define MTK_PHY_PAGE_EXTENDED_3 0x0003
#define MTK_PHY_RG_LPI_PCS_DSP_CTRL_REG11 0x11
@@ -220,6 +216,7 @@ static struct phy_driver mtk_gephy_driver[] = {
.name = "MediaTek MT7531 PHY",
.probe = mt7531_phy_probe,
.config_init = mt7531_phy_config_init,
+ .read_status = mtk_gphy_cl22_read_status,
/* Interrupts are handled by the switch, not the PHY
* itself.
*/
diff --git a/drivers/net/phy/mediatek/mtk-phy-lib.c b/drivers/net/phy/mediatek/mtk-phy-lib.c
index c51c9d8..e92102b 100644
--- a/drivers/net/phy/mediatek/mtk-phy-lib.c
+++ b/drivers/net/phy/mediatek/mtk-phy-lib.c
@@ -108,6 +108,96 @@ int mtk_phy_write_page(struct phy_device *phydev, int page)
}
EXPORT_SYMBOL_GPL(mtk_phy_write_page);
+/* This function deals with the case that 1G AN starts but isn't completed. We
+ * set AN_NEW_LP_CNT_LIMIT with different values time after time to let our
+ * 1G->100Mbps hardware automatic downshift to fit more partner devices.
+ */
+static int extend_an_new_lp_cnt_limit(struct phy_device *phydev)
+{
+ int mmd_read_ret;
+ u32 reg_val;
+ int timeout;
+
+ /* According to table 28-9 & Figure 28-18 in IEEE 802.3,
+ * link_fail_inhibit_timer of 10/100/1000 Mbps devices ranges from 750
+ * to "1000ms". Once MTK_PHY_FINAL_SPEED_1000 is set, it means that we
+ * enter "FLP LINK GOOD CHECK" state, link_fail_inhibit_timer starts and
+ * this PHY's 1G training starts. If 1G training never starts, we do
+ * nothing but leave.
+ */
+ timeout = read_poll_timeout(mmd_read_ret = phy_read_mmd, reg_val,
+ (mmd_read_ret < 0) ||
+ reg_val & MTK_PHY_FINAL_SPEED_1000,
+ 10000, 1000000, false, phydev,
+ MDIO_MMD_VEND1, MTK_PHY_LINK_STATUS_MISC);
+ if (mmd_read_ret < 0)
+ return mmd_read_ret;
+
+ if (!timeout) {
+ /* Once we found MTK_PHY_FINAL_SPEED_1000 is set, no matter 1G
+ * AN is completed or not, we'll set AN_NEW_LP_CNT_LIMIT again
+ * and again.
+ */
+ tr_modify(phydev, 0x0, 0xf, 0x3c, AN_NEW_LP_CNT_LIMIT_MASK,
+ FIELD_PREP(AN_NEW_LP_CNT_LIMIT_MASK, 0xf));
+ mdelay(1500);
+
+ timeout = read_poll_timeout(tr_read, reg_val,
+ (reg_val & AN_STATE_MASK) !=
+ (AN_STATE_TX_DISABLE <<
+ AN_STATE_SHIFT),
+ 10000, 1000000, false, phydev,
+ 0x0, 0xf, 0x2);
+ if (!timeout) {
+ mdelay(625);
+ tr_modify(phydev, 0x0, 0xf, 0x3c,
+ AN_NEW_LP_CNT_LIMIT_MASK,
+ FIELD_PREP(AN_NEW_LP_CNT_LIMIT_MASK, 0x8));
+ mdelay(500);
+ tr_modify(phydev, 0x0, 0xf, 0x3c,
+ AN_NEW_LP_CNT_LIMIT_MASK,
+ FIELD_PREP(AN_NEW_LP_CNT_LIMIT_MASK, 0xf));
+ } else {
+ return -ETIMEDOUT;
+ }
+ }
+
+ return 0;
+}
+
+int mtk_gphy_cl22_read_status(struct phy_device *phydev)
+{
+ int ret;
+
+ ret = genphy_read_status(phydev);
+ if (ret)
+ return ret;
+
+ if (phydev->autoneg == AUTONEG_ENABLE && !phydev->autoneg_complete) {
+ ret = phy_read_paged(phydev, MTK_PHY_PAGE_EXTENDED_1,
+ MTK_PHY_AUX_CTRL_AND_STATUS);
+ if (ret < 0)
+ return ret;
+
+ /* Once LP_DETECTED is set, it means that"ability_match" in
+ * IEEE 802.3 Figure 28-18 is set. This happens after we plug in
+ * cable. Also, LP_DETECTED will be cleared after AN complete.
+ */
+ if (!FIELD_GET(MTK_PHY_LP_DETECTED_MASK, ret))
+ return 0;
+
+ ret = phy_read(phydev, MII_CTRL1000);
+ if (ret & (ADVERTISE_1000FULL | ADVERTISE_1000HALF)) {
+ ret = extend_an_new_lp_cnt_limit(phydev);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(mtk_gphy_cl22_read_status);
+
int mtk_phy_led_hw_is_supported(struct phy_device *phydev, u8 index,
unsigned long rules,
unsigned long supported_triggers)
diff --git a/drivers/net/phy/mediatek/mtk.h b/drivers/net/phy/mediatek/mtk.h
index d27226d..2bec3b1 100644
--- a/drivers/net/phy/mediatek/mtk.h
+++ b/drivers/net/phy/mediatek/mtk.h
@@ -10,8 +10,28 @@
#define MTK_EXT_PAGE_ACCESS 0x1f
#define MTK_PHY_PAGE_STANDARD 0x0000
+#define MTK_PHY_PAGE_EXTENDED_1 0x0001
+#define MTK_PHY_AUX_CTRL_AND_STATUS 0x14
+/* suprv_media_select_RefClk */
+#define MTK_PHY_LP_DETECTED_MASK GENMASK(7, 6)
+#define MTK_PHY_ENABLE_DOWNSHIFT BIT(4)
+
#define MTK_PHY_PAGE_EXTENDED_52B5 0x52b5
+/* Registers on Token Ring debug nodes */
+/* ch_addr = 0x0, node_addr = 0xf, data_addr = 0x2 */
+#define AN_STATE_MASK GENMASK(22, 19)
+#define AN_STATE_SHIFT 19
+#define AN_STATE_TX_DISABLE 1
+
+/* ch_addr = 0x0, node_addr = 0xf, data_addr = 0x3c */
+#define AN_NEW_LP_CNT_LIMIT_MASK GENMASK(23, 20)
+#define AUTO_NP_10XEN BIT(6)
+
+/* Registers on MDIO_MMD_VEND1 */
+#define MTK_PHY_LINK_STATUS_MISC (0xa2)
+#define MTK_PHY_FINAL_SPEED_1000 BIT(3)
+
/* Registers on MDIO_MMD_VEND2 */
#define MTK_PHY_LED0_ON_CTRL 0x24
#define MTK_PHY_LED1_ON_CTRL 0x26
@@ -77,6 +97,7 @@ void __tr_clr_bits(struct phy_device *phydev, u8 ch_addr, u8 node_addr,
int mtk_phy_read_page(struct phy_device *phydev);
int mtk_phy_write_page(struct phy_device *phydev, int page);
+int mtk_gphy_cl22_read_status(struct phy_device *phydev);
int mtk_phy_led_hw_is_supported(struct phy_device *phydev, u8 index,
unsigned long rules,
unsigned long supported_triggers);
--
2.34.1