[net,v2, 0/4] Bug fixes to amd-xgbe driver

[net,v2, 0/4] Bug fixes to amd-xgbe driver

[Shyam Sundar S K]

General fixes on amd-xgbe driver are addressed in this series, mostly
on the mailbox communication failures and improving the link stability
of the amd-xgbe device.

Shyam Sundar S K (4):
  net: amd-xgbe: Reset the PHY rx data path when mailbox command timeout
  net: amd-xgbe: Fix NETDEV WATCHDOG transmit queue timeout warning
  net: amd-xgbe: Reset link when the link never comes back
  net: amd-xgbe: Fix network fluctuations when using 1G BELFUSE SFP

 drivers/net/ethernet/amd/xgbe/xgbe-common.h | 14 ++++++++
 drivers/net/ethernet/amd/xgbe/xgbe-drv.c    |  1 +
 drivers/net/ethernet/amd/xgbe/xgbe-mdio.c   |  3 +-
 drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c | 39 ++++++++++++++++++++-
 4 files changed, 54 insertions(+), 3 deletions(-)

-- 
2.25.1

[net,v2, 1/4] net: amd-xgbe: Reset the PHY rx data path when mailbox command timeout

[Shyam Sundar S K]

Sometimes mailbox commands timeout when the RX data path becomes
unresponsive. This prevents the submission of new mailbox commands to DXIO.
This patch identifies the timeout and resets the RX data path so that the
next message can be submitted properly.

Fixes: 549b32af9f7c ("amd-xgbe: Simplify mailbox interface rate change code")
Co-developed-by: Sudheesh Mavila <sudheesh.mavila@amd.com>
Signed-off-by: Sudheesh Mavila <sudheesh.mavila@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
---
v1->v2:
- Add Co-Developed-by: and Fixes: tag
- Changes suggested by Tom on right usage for PSEQ_STATE.

 drivers/net/ethernet/amd/xgbe/xgbe-common.h | 14 +++++++++++
 drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c | 28 ++++++++++++++++++++-
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-common.h b/drivers/net/ethernet/amd/xgbe/xgbe-common.h
index b40d4377cc71..b2cd3bdba9f8 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-common.h
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-common.h
@@ -1279,10 +1279,18 @@
 #define MDIO_PMA_10GBR_FECCTRL		0x00ab
 #endif
 
+#ifndef MDIO_PMA_RX_CTRL1
+#define MDIO_PMA_RX_CTRL1		0x8051
+#endif
+
 #ifndef MDIO_PCS_DIG_CTRL
 #define MDIO_PCS_DIG_CTRL		0x8000
 #endif
 
+#ifndef MDIO_PCS_DIGITAL_STAT
+#define MDIO_PCS_DIGITAL_STAT		0x8010
+#endif
+
 #ifndef MDIO_AN_XNP
 #define MDIO_AN_XNP			0x0016
 #endif
@@ -1358,6 +1366,8 @@
 #define XGBE_KR_TRAINING_ENABLE		BIT(1)
 
 #define XGBE_PCS_CL37_BP		BIT(12)
+#define XGBE_PCS_PSEQ_STATE_MASK	0x1c
+#define XGBE_PCS_PSEQ_STATE_POWER_GOOD	0x10
 
 #define XGBE_AN_CL37_INT_CMPLT		BIT(0)
 #define XGBE_AN_CL37_INT_MASK		0x01
@@ -1375,6 +1385,10 @@
 #define XGBE_PMA_CDR_TRACK_EN_OFF	0x00
 #define XGBE_PMA_CDR_TRACK_EN_ON	0x01
 
+#define XGBE_PMA_RX_RST_0_MASK		BIT(4)
+#define XGBE_PMA_RX_RST_0_RESET_ON	0x10
+#define XGBE_PMA_RX_RST_0_RESET_OFF	0x00
+
 /* Bit setting and getting macros
  *  The get macro will extract the current bit field value from within
  *  the variable
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
index 859ded0c06b0..087948085ae1 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
@@ -1953,6 +1953,27 @@ static void xgbe_phy_set_redrv_mode(struct xgbe_prv_data *pdata)
 	xgbe_phy_put_comm_ownership(pdata);
 }
 
+static void xgbe_phy_rx_reset(struct xgbe_prv_data *pdata)
+{
+	int reg;
+
+	reg = XMDIO_READ_BITS(pdata, MDIO_MMD_PCS, MDIO_PCS_DIGITAL_STAT,
+			      XGBE_PCS_PSEQ_STATE_MASK);
+	if (reg == XGBE_PCS_PSEQ_STATE_POWER_GOOD) {
+		/* Mailbox command timed out, reset of RX block is required.
+		 * This can be done by asseting the reset bit and wait for
+		 * its compeletion.
+		 */
+		XMDIO_WRITE_BITS(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_RX_CTRL1,
+				 XGBE_PMA_RX_RST_0_MASK, XGBE_PMA_RX_RST_0_RESET_ON);
+		ndelay(20);
+		XMDIO_WRITE_BITS(pdata, MDIO_MMD_PMAPMD, MDIO_PMA_RX_CTRL1,
+				 XGBE_PMA_RX_RST_0_MASK, XGBE_PMA_RX_RST_0_RESET_OFF);
+		usleep_range(40, 50);
+		netif_err(pdata, link, pdata->netdev, "firmware mailbox reset performed\n");
+	}
+}
+
 static void xgbe_phy_perform_ratechange(struct xgbe_prv_data *pdata,
 					unsigned int cmd, unsigned int sub_cmd)
 {
@@ -1960,9 +1981,11 @@ static void xgbe_phy_perform_ratechange(struct xgbe_prv_data *pdata,
 	unsigned int wait;
 
 	/* Log if a previous command did not complete */
-	if (XP_IOREAD_BITS(pdata, XP_DRIVER_INT_RO, STATUS))
+	if (XP_IOREAD_BITS(pdata, XP_DRIVER_INT_RO, STATUS)) {
 		netif_dbg(pdata, link, pdata->netdev,
 			  "firmware mailbox not ready for command\n");
+		xgbe_phy_rx_reset(pdata);
+	}
 
 	/* Construct the command */
 	XP_SET_BITS(s0, XP_DRIVER_SCRATCH_0, COMMAND, cmd);
@@ -1984,6 +2007,9 @@ static void xgbe_phy_perform_ratechange(struct xgbe_prv_data *pdata,
 
 	netif_dbg(pdata, link, pdata->netdev,
 		  "firmware mailbox command did not complete\n");
+
+	/* Reset on error */
+	xgbe_phy_rx_reset(pdata);
 }
 
 static void xgbe_phy_rrc(struct xgbe_prv_data *pdata)
-- 
2.25.1

[net,v2, 2/4] net: amd-xgbe: Fix NETDEV WATCHDOG transmit queue timeout warning

[Shyam Sundar S K]

The current driver calls netif_carrier_off() late in the link tear down
which can result in a netdev watchdog timeout.

Calling netif_carrier_off() immediately after netif_tx_stop_all_queues()
avoids the warning.

 ------------[ cut here ]------------
 NETDEV WATCHDOG: enp3s0f2 (amd-xgbe): transmit queue 0 timed out
 WARNING: CPU: 3 PID: 0 at net/sched/sch_generic.c:461 dev_watchdog+0x20d/0x220
 Modules linked in: amd_xgbe(E)  amd-xgbe 0000:03:00.2 enp3s0f2: Link is Down
 CPU: 3 PID: 0 Comm: swapper/3 Tainted: G            E
 Hardware name: AMD Bilby-RV2/Bilby-RV2, BIOS RBB1202A 10/18/2019
 RIP: 0010:dev_watchdog+0x20d/0x220
 Code: 00 49 63 4e e0 eb 92 4c 89 e7 c6 05 c6 e2 c1 00 01 e8 e7 ce fc ff 89 d9 48
 RSP: 0018:ffff90cfc28c3e88 EFLAGS: 00010286
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006
 RDX: 0000000000000007 RSI: 0000000000000086 RDI: ffff90cfc28d63c0
 RBP: ffff90cfb977845c R08: 0000000000000050 R09: 0000000000196018
 R10: ffff90cfc28c3ef8 R11: 0000000000000000 R12: ffff90cfb9778000
 R13: 0000000000000003 R14: ffff90cfb9778480 R15: 0000000000000010
 FS:  0000000000000000(0000) GS:ffff90cfc28c0000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f240ff2d9d0 CR3: 00000001e3e0a000 CR4: 00000000003406e0
 Call Trace:
  <IRQ>
  ? pfifo_fast_reset+0x100/0x100
  call_timer_fn+0x2b/0x130
  run_timer_softirq+0x3e8/0x440
  ? enqueue_hrtimer+0x39/0x90

Fixes: e722ec82374b ("amd-xgbe: Update the BelFuse quirk to support SGMII")
Co-developed-by: Sudheesh Mavila <sudheesh.mavila@amd.com>
Signed-off-by: Sudheesh Mavila <sudheesh.mavila@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
---
v1->v2:
- Add Co-Developed-by: and Fixes: tag
- Commit message changes.

 drivers/net/ethernet/amd/xgbe/xgbe-drv.c  | 1 +
 drivers/net/ethernet/amd/xgbe/xgbe-mdio.c | 1 -
 2 files changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
index 2709a2db5657..395eb0b52680 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
@@ -1368,6 +1368,7 @@ static void xgbe_stop(struct xgbe_prv_data *pdata)
 		return;
 
 	netif_tx_stop_all_queues(netdev);
+	netif_carrier_off(pdata->netdev);
 
 	xgbe_stop_timers(pdata);
 	flush_workqueue(pdata->dev_workqueue);
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c
index 93ef5a30cb8d..19ee4db0156d 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c
@@ -1396,7 +1396,6 @@ static void xgbe_phy_stop(struct xgbe_prv_data *pdata)
 	pdata->phy_if.phy_impl.stop(pdata);
 
 	pdata->phy.link = 0;
-	netif_carrier_off(pdata->netdev);
 
 	xgbe_phy_adjust_link(pdata);
 }
-- 
2.25.1

[net,v2, 3/4] net: amd-xgbe: Reset link when the link never comes back

[Shyam Sundar S K]

Normally, auto negotiation and reconnect should be automatically done by
the hardware. But there seems to be an issue where auto negotiation has
to be restarted manually. This happens because of link training and so
even though still connected to the partner the link never "comes back".
This needs an auto-negotiation restart.

Also, a change in xgbe-mdio is needed to get ethtool to recognize the
link down and get the link change message. This change is only
required in a backplane connection mode.

Fixes: abf0a1c2b26a ("amd-xgbe: Add support for SFP+ modules")
Co-developed-by: Sudheesh Mavila <sudheesh.mavila@amd.com>
Signed-off-by: Sudheesh Mavila <sudheesh.mavila@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
---
v1->v2:
- Commit message changes
- Add Co-Developed-by: and Fixes: tag

 drivers/net/ethernet/amd/xgbe/xgbe-mdio.c   | 2 +-
 drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c
index 19ee4db0156d..4e97b4869522 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c
@@ -1345,7 +1345,7 @@ static void xgbe_phy_status(struct xgbe_prv_data *pdata)
 							     &an_restart);
 	if (an_restart) {
 		xgbe_phy_config_aneg(pdata);
-		return;
+		goto adjust_link;
 	}
 
 	if (pdata->phy.link) {
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
index 087948085ae1..d3f72faecd1d 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
@@ -2610,6 +2610,14 @@ static int xgbe_phy_link_status(struct xgbe_prv_data *pdata, int *an_restart)
 	if (reg & MDIO_STAT1_LSTATUS)
 		return 1;
 
+	if (pdata->phy.autoneg == AUTONEG_ENABLE &&
+	    phy_data->port_mode == XGBE_PORT_MODE_BACKPLANE) {
+		if (!test_bit(XGBE_LINK_INIT, &pdata->dev_state)) {
+			netif_carrier_off(pdata->netdev);
+			*an_restart = 1;
+		}
+	}
+
 	/* No link, attempt a receiver reset cycle */
 	if (phy_data->rrc_count++ > XGBE_RRC_FREQUENCY) {
 		phy_data->rrc_count = 0;
-- 
2.25.1

[net,v2, 4/4] net: amd-xgbe: Fix network fluctuations when using 1G BELFUSE SFP

[Shyam Sundar S K]

Frequent link up/down events can happen when a Bel Fuse SFP part is
connected to the amd-xgbe device. Try to avoid the frequent link
issues by resetting the PHY as documented in Bel Fuse SFP datasheets.

Fixes: e722ec82374b ("amd-xgbe: Update the BelFuse quirk to support SGMII")
Co-developed-by: Sudheesh Mavila <sudheesh.mavila@amd.com>
Signed-off-by: Sudheesh Mavila <sudheesh.mavila@amd.com>
Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
---
v1->v2:
- Add Co-Developed-by: and Fixes: tag
- Use genphy_soft_reset() as suggested by Florian.

 drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
index d3f72faecd1d..18e48b3bc402 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-phy-v2.c
@@ -922,6 +922,9 @@ static bool xgbe_phy_belfuse_phy_quirks(struct xgbe_prv_data *pdata)
 	if ((phy_id & 0xfffffff0) != 0x03625d10)
 		return false;
 
+	/* Reset PHY - wait for self-clearing reset bit to clear */
+	genphy_soft_reset(phy_data->phydev);
+
 	/* Disable RGMII mode */
 	phy_write(phy_data->phydev, 0x18, 0x7007);
 	reg = phy_read(phy_data->phydev, 0x18);
-- 
2.25.1

Re: [net,v2, 0/4] Bug fixes to amd-xgbe driver

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net.git (refs/heads/master):

On Wed, 17 Feb 2021 00:37:06 +0530 you wrote:
> General fixes on amd-xgbe driver are addressed in this series, mostly
> on the mailbox communication failures and improving the link stability
> of the amd-xgbe device.
> 
> Shyam Sundar S K (4):
>   net: amd-xgbe: Reset the PHY rx data path when mailbox command timeout
>   net: amd-xgbe: Fix NETDEV WATCHDOG transmit queue timeout warning
>   net: amd-xgbe: Reset link when the link never comes back
>   net: amd-xgbe: Fix network fluctuations when using 1G BELFUSE SFP
> 
> [...]

Here is the summary with links:
  - [net,v2,1/4] net: amd-xgbe: Reset the PHY rx data path when mailbox command timeout
    https://git.kernel.org/netdev/net/c/30b7edc82ec8
  - [net,v2,2/4] net: amd-xgbe: Fix NETDEV WATCHDOG transmit queue timeout warning
    https://git.kernel.org/netdev/net/c/186edbb510bd
  - [net,v2,3/4] net: amd-xgbe: Reset link when the link never comes back
    https://git.kernel.org/netdev/net/c/84fe68eb67f9
  - [net,v2,4/4] net: amd-xgbe: Fix network fluctuations when using 1G BELFUSE SFP
    https://git.kernel.org/netdev/net/c/9eab3fdb4199

You are awesome, thank you!
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