Commit 3a55402c9387 ("net: bcmgenet: use RGMII loopback for MAC
reset") was intended to resolve issues with reseting the UniMAC
core within the GENET block by providing better control over the
clocks used by the UniMAC core. Unfortunately, it is not
compatible with all of the supported system configurations so an
alternative method must be applied.
This commit set provides such an alternative. The first commit
reverts the previous change and the second commit provides the
alternative reset sequence that addresses the concerns observed
with the previous implementation.
This replacement implementation should be applied to the stable
branches wherever commit 3a55402c9387 ("net: bcmgenet: use RGMII
loopback for MAC reset") has been applied.
Unfortunately, reverting that commit may conflict with some
restructuring changes introduced by commit 4f8d81b77e66 ("net:
bcmgenet: Refactor register access in bcmgenet_mii_config").
The first commit in this set has been manually edited to
resolve the conflict on stable/linux-5.4.y.
Doug Berger (2):
Revert "net: bcmgenet: use RGMII loopback for MAC reset"
net: bcmgenet: keep MAC in reset until PHY is up
.../net/ethernet/broadcom/genet/bcmgenet.c | 10 ++---
.../ethernet/broadcom/genet/bcmgenet_wol.c | 6 ++-
drivers/net/ethernet/broadcom/genet/bcmmii.c | 39 +++----------------
3 files changed, 16 insertions(+), 39 deletions(-)
--
2.34.1
[ Upstream commit 612eb1c3b9e504de24136c947ed7c07bc342f3aa ]
This reverts commit 3a55402c93877d291b0a612d25edb03d1b4b93ac.
This is not a good solution when connecting to an external switch
that may not support the isolation of the TXC signal resulting in
output driver contention on the pin.
A different solution is necessary.
Signed-off-by: Doug Berger <[email protected]>
Acked-by: Florian Fainelli <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
[Adjusted to accommodate lack of commit 4f8d81b77e66]
Signed-off-by: Doug Berger <[email protected]>
---
.../net/ethernet/broadcom/genet/bcmgenet.c | 2 ++
drivers/net/ethernet/broadcom/genet/bcmmii.c | 33 -------------------
2 files changed, 2 insertions(+), 33 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 380bf7a328ba..2afd056056fb 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -2015,6 +2015,8 @@ static void reset_umac(struct bcmgenet_priv *priv)
/* issue soft reset with (rg)mii loopback to ensure a stable rxclk */
bcmgenet_umac_writel(priv, CMD_SW_RESET | CMD_LCL_LOOP_EN, UMAC_CMD);
+ udelay(2);
+ bcmgenet_umac_writel(priv, 0, UMAC_CMD);
}
static void bcmgenet_intr_disable(struct bcmgenet_priv *priv)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 026f00ccaa0c..213434aaf07f 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -187,38 +187,8 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
const char *phy_name = NULL;
u32 id_mode_dis = 0;
u32 port_ctrl;
- int bmcr = -1;
- int ret;
u32 reg;
- /* MAC clocking workaround during reset of umac state machines */
- reg = bcmgenet_umac_readl(priv, UMAC_CMD);
- if (reg & CMD_SW_RESET) {
- /* An MII PHY must be isolated to prevent TXC contention */
- if (priv->phy_interface == PHY_INTERFACE_MODE_MII) {
- ret = phy_read(phydev, MII_BMCR);
- if (ret >= 0) {
- bmcr = ret;
- ret = phy_write(phydev, MII_BMCR,
- bmcr | BMCR_ISOLATE);
- }
- if (ret) {
- netdev_err(dev, "failed to isolate PHY\n");
- return ret;
- }
- }
- /* Switch MAC clocking to RGMII generated clock */
- bcmgenet_sys_writel(priv, PORT_MODE_EXT_GPHY, SYS_PORT_CTRL);
- /* Ensure 5 clks with Rx disabled
- * followed by 5 clks with Reset asserted
- */
- udelay(4);
- reg &= ~(CMD_SW_RESET | CMD_LCL_LOOP_EN);
- bcmgenet_umac_writel(priv, reg, UMAC_CMD);
- /* Ensure 5 more clocks before Rx is enabled */
- udelay(2);
- }
-
priv->ext_phy = !priv->internal_phy &&
(priv->phy_interface != PHY_INTERFACE_MODE_MOCA);
@@ -250,9 +220,6 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
phy_set_max_speed(phydev, SPEED_100);
bcmgenet_sys_writel(priv,
PORT_MODE_EXT_EPHY, SYS_PORT_CTRL);
- /* Restore the MII PHY after isolation */
- if (bmcr >= 0)
- phy_write(phydev, MII_BMCR, bmcr);
break;
case PHY_INTERFACE_MODE_REVMII:
--
2.34.1
[ Upstream commit 88f6c8bf1aaed5039923fb4c701cab4d42176275 ]
As noted in commit 28c2d1a7a0bf ("net: bcmgenet: enable loopback
during UniMAC sw_reset") the UniMAC must be clocked at least 5
cycles while the sw_reset is asserted to ensure a clean reset.
That commit enabled local loopback to provide an Rx clock from the
GENET sourced Tx clk. However, when connected in MII mode the Tx
clk is sourced by the PHY so if an EPHY is not supplying clocks
(e.g. when the link is down) the UniMAC does not receive the
necessary clocks.
This commit extends the sw_reset window until the PHY reports that
the link is up thereby ensuring that the clocks are being provided
to the MAC to produce a clean reset.
One consequence is that if the system attempts to enter a Wake on
LAN suspend state when the PHY link has not been active the MAC
may not have had a chance to initialize cleanly. In this case, we
remove the sw_reset and enable the WoL reception path as normal
with the hope that the PHY will provide the necessary clocks to
drive the WoL blocks if the link becomes active after the system
has entered suspend.
Fixes: 1c1008c793fa ("net: bcmgenet: add main driver file")
Signed-off-by: Doug Berger <[email protected]>
Acked-by: Florian Fainelli <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
---
drivers/net/ethernet/broadcom/genet/bcmgenet.c | 10 ++++------
drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c | 6 +++++-
drivers/net/ethernet/broadcom/genet/bcmmii.c | 6 ++++++
3 files changed, 15 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 2afd056056fb..bf52bd643846 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -1991,6 +1991,8 @@ static void umac_enable_set(struct bcmgenet_priv *priv, u32 mask, bool enable)
u32 reg;
reg = bcmgenet_umac_readl(priv, UMAC_CMD);
+ if (reg & CMD_SW_RESET)
+ return;
if (enable)
reg |= mask;
else
@@ -2010,13 +2012,9 @@ static void reset_umac(struct bcmgenet_priv *priv)
bcmgenet_rbuf_ctrl_set(priv, 0);
udelay(10);
- /* disable MAC while updating its registers */
- bcmgenet_umac_writel(priv, 0, UMAC_CMD);
-
- /* issue soft reset with (rg)mii loopback to ensure a stable rxclk */
- bcmgenet_umac_writel(priv, CMD_SW_RESET | CMD_LCL_LOOP_EN, UMAC_CMD);
+ /* issue soft reset and disable MAC while updating its registers */
+ bcmgenet_umac_writel(priv, CMD_SW_RESET, UMAC_CMD);
udelay(2);
- bcmgenet_umac_writel(priv, 0, UMAC_CMD);
}
static void bcmgenet_intr_disable(struct bcmgenet_priv *priv)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c b/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
index a2da09da4907..8ebca6bf300e 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
@@ -132,8 +132,12 @@ int bcmgenet_wol_power_down_cfg(struct bcmgenet_priv *priv,
return -EINVAL;
}
- /* disable RX */
+ /* Can't suspend with WoL if MAC is still in reset */
reg = bcmgenet_umac_readl(priv, UMAC_CMD);
+ if (reg & CMD_SW_RESET)
+ reg &= ~CMD_SW_RESET;
+
+ /* disable RX */
reg &= ~CMD_RX_EN;
bcmgenet_umac_writel(priv, reg, UMAC_CMD);
mdelay(10);
diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 213434aaf07f..56fad34461f7 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -96,6 +96,12 @@ void bcmgenet_mii_setup(struct net_device *dev)
CMD_HD_EN |
CMD_RX_PAUSE_IGNORE | CMD_TX_PAUSE_IGNORE);
reg |= cmd_bits;
+ if (reg & CMD_SW_RESET) {
+ reg &= ~CMD_SW_RESET;
+ bcmgenet_umac_writel(priv, reg, UMAC_CMD);
+ udelay(2);
+ reg |= CMD_TX_EN | CMD_RX_EN;
+ }
bcmgenet_umac_writel(priv, reg, UMAC_CMD);
priv->eee.eee_active = phy_init_eee(phydev, 0) >= 0;
--
2.34.1
On Thu, May 16, 2024 at 02:11:51PM -0700, Doug Berger wrote:
> Commit 3a55402c9387 ("net: bcmgenet: use RGMII loopback for MAC
> reset") was intended to resolve issues with reseting the UniMAC
> core within the GENET block by providing better control over the
> clocks used by the UniMAC core. Unfortunately, it is not
> compatible with all of the supported system configurations so an
> alternative method must be applied.
>
> This commit set provides such an alternative. The first commit
> reverts the previous change and the second commit provides the
> alternative reset sequence that addresses the concerns observed
> with the previous implementation.
>
> This replacement implementation should be applied to the stable
> branches wherever commit 3a55402c9387 ("net: bcmgenet: use RGMII
> loopback for MAC reset") has been applied.
>
> Unfortunately, reverting that commit may conflict with some
> restructuring changes introduced by commit 4f8d81b77e66 ("net:
> bcmgenet: Refactor register access in bcmgenet_mii_config").
> The first commit in this set has been manually edited to
> resolve the conflict on stable/linux-5.4.y.
>
> Doug Berger (2):
> Revert "net: bcmgenet: use RGMII loopback for MAC reset"
> net: bcmgenet: keep MAC in reset until PHY is up
>
> .../net/ethernet/broadcom/genet/bcmgenet.c | 10 ++---
> .../ethernet/broadcom/genet/bcmgenet_wol.c | 6 ++-
> drivers/net/ethernet/broadcom/genet/bcmmii.c | 39 +++----------------
> 3 files changed, 16 insertions(+), 39 deletions(-)
>
> --
> 2.34.1
>
>
Both now queued up, thanks.
greg k-h