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net: dsa: mxl862xx: support firmware update

PATCH Superseded Daniel Golle 3 participants 8 messages Jul 14 – Jul 22

Subsystems (4)

v2 of 19 Superseded Latest is v19 →

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Daniel Golle

author maintainer
#0 lore raw

v2 cover net: dsa: mxl862xx: support firmware update

The firmware of MxL862xx managed Ethernet switches can be updated in-system via the same MDIO bus which is also used to manage the switch. Wire up the devlink flash_update operation for DSA drivers and implement firmware update and version reporting in the mxl862xx driver.

Changes since RFC [1]:
- detect a switch stuck in MCUboot rescue mode at probe, register the switch without any ports and report "mcuboot-rescue" as the running firmware version, so devlink flash can recover from a failed or interrupted update (Andrew Lunn)
- clarify in the commit message of patch 2 that the per-transaction MDIO bus locking is about other, non-switch devices on the same MDIO bus (Andrew Lunn)
- mention in the commit message of patch 3 that closing the ports also stops phylib from polling the switch-internal PHYs during the transfer (Andrew Lunn)
- split up run-on sentence and explain the dynamically allocated reprobe work item instead of just pointing at iwlwifi in the commit message of patch 3 (Manuel Ebner)
- use kzalloc_obj() (Manuel Ebner)
- state the actual duration of a complete flash and reprobe cycle (just under a minute) in comments and the commit message, and clarify that the timeout values are generous upper bounds (Manuel Ebner)

[1] https://lore.kernel.org/all/[email protected]/

Daniel Golle (4):
net: dsa: wire flash_update devlink callback to drivers
net: dsa: mxl862xx: add SMDIO clause-22 register access
net: dsa: mxl862xx: add devlink flash_update and info_get
net: dsa: mxl862xx: recover switch stuck in MCUboot rescue mode

 drivers/net/dsa/mxl862xx/Makefile           |   2 +-
 drivers/net/dsa/mxl862xx/mxl862xx-cmd.h     |   1 +
 drivers/net/dsa/mxl862xx/mxl862xx-fw.c      | 439 ++++++++++++++++++++
 drivers/net/dsa/mxl862xx/mxl862xx-fw.h      |  18 +
 drivers/net/dsa/mxl862xx/mxl862xx-host.c    |  45 ++
 drivers/net/dsa/mxl862xx/mxl862xx-host.h    |   2 +
 drivers/net/dsa/mxl862xx/mxl862xx-phylink.c |   2 +
 drivers/net/dsa/mxl862xx/mxl862xx.c         |  41 +-
 drivers/net/dsa/mxl862xx/mxl862xx.h         |   9 +
 include/net/dsa.h                           |   3 +
 net/dsa/devlink.c                           |  13 +
 11 files changed, 571 insertions(+), 4 deletions(-)
 create mode 100644 drivers/net/dsa/mxl862xx/mxl862xx-fw.c
 create mode 100644 drivers/net/dsa/mxl862xx/mxl862xx-fw.h

base-commit: f6f3b36c15ed44de1fbb44e645e4fae8c4a4453e

Signature · 1 line
2.55.0
author maintainer
#1 lore raw

PATCH v2 1/4 net: dsa: wire flash_update devlink callback to drivers

Add a devlink_flash_update callback to dsa_switch_ops so that DSA drivers can support devlink dev flash without open-coding the devlink plumbing. The new trampoline in net/dsa/devlink.c follows the existing dsa_devlink_info_get pattern exactly.

---
v2: align continuation lines with the open parenthesis

 include/net/dsa.h |  3 +++
 net/dsa/devlink.c | 13 +++++++++++++
 2 files changed, 16 insertions(+)
include/net/dsa.h +3 -0
index 8c16ef23cc10..c9e19348de61 100644
@@ -1170,6 +1170,9 @@ struct dsa_switch_ops {
 	int	(*devlink_info_get)(struct dsa_switch *ds,
 				    struct devlink_info_req *req,
 				    struct netlink_ext_ack *extack);
+	int	(*devlink_flash_update)(struct dsa_switch *ds,
+					struct devlink_flash_update_params *params,
+					struct netlink_ext_ack *extack);
 	int	(*devlink_sb_pool_get)(struct dsa_switch *ds,
 				       unsigned int sb_index, u16 pool_index,
 				       struct devlink_sb_pool_info *pool_info);
net/dsa/devlink.c +13 -0
index ed342f345692..25311a87cbc5 100644
@@ -20,6 +20,18 @@ static int dsa_devlink_info_get(struct devlink *dl,
 	return -EOPNOTSUPP;
 }
 
+static int dsa_devlink_flash_update(struct devlink *dl,
+				    struct devlink_flash_update_params *params,
+				    struct netlink_ext_ack *extack)
+{
+	struct dsa_switch *ds = dsa_devlink_to_ds(dl);
+
+	if (!ds->ops->devlink_flash_update)
+		return -EOPNOTSUPP;
+
+	return ds->ops->devlink_flash_update(ds, params, extack);
+}
+
 static int dsa_devlink_sb_pool_get(struct devlink *dl,
 				   unsigned int sb_index, u16 pool_index,
 				   struct devlink_sb_pool_info *pool_info)
@@ -169,6 +181,7 @@ dsa_devlink_sb_occ_tc_port_bind_get(struct devlink_port *dlp,
 
 static const struct devlink_ops dsa_devlink_ops = {
 	.info_get			= dsa_devlink_info_get,
+	.flash_update			= dsa_devlink_flash_update,
 	.sb_pool_get			= dsa_devlink_sb_pool_get,
 	.sb_pool_set			= dsa_devlink_sb_pool_set,
 	.sb_port_pool_get		= dsa_devlink_sb_port_pool_get,
Signature · 1 line
2.55.0
author maintainer
#2 lore raw

PATCH v2 2/4 net: dsa: mxl862xx: add SMDIO clause-22 register access

In reply to Daniel Golle

Add mxl862xx_smdio_read() and mxl862xx_smdio_write() for clause-22 SMDIO register access. MCUboot rescue mode only exposes clause-22 registers; the existing clause-45 MMD interface is unavailable during firmware transfer. The MDIO bus lock is held per-transaction (not across polls) so that SB PDI polling during flash erase does not starve other non-switch users of the same MDIO bus, such as separate PHYs providing WAN or management interfaces.

---
v2: clarify in the commit message that the per-transaction bus locking
is about unrelated non-switch devices on the same MDIO bus (Andrew Lunn)

 drivers/net/dsa/mxl862xx/mxl862xx-host.c | 35 ++++++++++++++++++++++++
 drivers/net/dsa/mxl862xx/mxl862xx-host.h |  2 ++
 2 files changed, 37 insertions(+)
drivers/net/dsa/mxl862xx/mxl862xx-host.c +35 -0
index 4acd216f7cc0..6e582caea1fa 100644
@@ -495,6 +495,41 @@ int mxl862xx_reset(struct mxl862xx_priv *priv)
 	return ret;
 }
 
+#define MXL862XX_SMDIO_ADDR_REG		0x1f
+#define MXL862XX_SMDIO_PAGE_MASK	0xfff0
+#define MXL862XX_SMDIO_OFF_MASK		0x000f
+
+int mxl862xx_smdio_read(struct mxl862xx_priv *priv, u32 addr)
+{
+	struct mii_bus *bus = priv->mdiodev->bus;
+	int phy = priv->mdiodev->addr;
+	int ret;
+
+	mutex_lock(&bus->mdio_lock);
+	ret = __mdiobus_write(bus, phy, MXL862XX_SMDIO_ADDR_REG,
+			      addr & MXL862XX_SMDIO_PAGE_MASK);
+	if (ret >= 0)
+		ret = __mdiobus_read(bus, phy, addr & MXL862XX_SMDIO_OFF_MASK);
+	mutex_unlock(&bus->mdio_lock);
+	return ret;
+}
+
+int mxl862xx_smdio_write(struct mxl862xx_priv *priv, u32 addr, u16 val)
+{
+	struct mii_bus *bus = priv->mdiodev->bus;
+	int phy = priv->mdiodev->addr;
+	int ret;
+
+	mutex_lock(&bus->mdio_lock);
+	ret = __mdiobus_write(bus, phy, MXL862XX_SMDIO_ADDR_REG,
+			      addr & MXL862XX_SMDIO_PAGE_MASK);
+	if (ret >= 0)
+		ret = __mdiobus_write(bus, phy, addr & MXL862XX_SMDIO_OFF_MASK,
+				      val);
+	mutex_unlock(&bus->mdio_lock);
+	return ret;
+}
+
 void mxl862xx_host_init(struct mxl862xx_priv *priv)
 {
 	INIT_WORK(&priv->crc_err_work, mxl862xx_crc_err_work_fn);
drivers/net/dsa/mxl862xx/mxl862xx-host.h +2 -0
index 66d6ae198aff..4e054c6e4c0e 100644
@@ -18,5 +18,7 @@ int mxl862xx_api_wrap(struct mxl862xx_priv *priv, u16 cmd, void *data, u16 size,
 	mxl862xx_api_wrap(dev, cmd, &(data), sizeof((data)), true, true)
 
 int mxl862xx_reset(struct mxl862xx_priv *priv);
+int mxl862xx_smdio_read(struct mxl862xx_priv *priv, u32 addr);
+int mxl862xx_smdio_write(struct mxl862xx_priv *priv, u32 addr, u16 val);
 
 #endif /* __MXL862XX_HOST_H */
Signature · 1 line
2.55.0
author maintainer
#3 lore raw

PATCH v2 3/4 net: dsa: mxl862xx: add devlink flash_update and info_get

In reply to Daniel Golle

Implement runtime firmware upgrade via "devlink dev flash" and version reporting via "devlink dev info":

devlink dev info mdio_bus/<bus>/<addr>
devlink dev flash mdio_bus/<bus>/<addr> file <firmware.bin>

The driver sends SYS_MISC_FW_UPDATE to enter MCUboot rescue mode and transfers the signed image over the SB PDI bulk-transfer protocol (clause-22 SMDIO). Once the transfer has finished and the switch has rebooted, the driver schedules device_reprobe() for a clean remove()+probe() cycle.

Before the transfer begins the driver closes all conduit interfaces and marks every netdev (user and conduit) not-present via netif_device_detach() so that userspace cannot bring ports back up during the flash and reprobe cycle, which takes just under a minute. Closing the ports also stops phylib from polling the switch-internal PHYs, whose firmware-relayed MDIO access is unavailable while the switch is in MCUboot mode. Progress is reported through devlink status notifications. Once the FW_UPDATE command has been sent the switch is in MCUboot mode and normal operation can only be restored by a reprobe, so the driver always schedules one regardless of transfer outcome.

The reprobe work item is dynamically allocated because device_reprobe() triggers remove() which frees the devm-managed priv while the work item is still executing, so the work struct cannot be a member of priv. iwlwifi uses the same approach for its firmware-triggered device removal, see iwl_trans_pcie_removal_wk().

---
v2:
- factor out SB PDI slice flush and devlink status notification helpers, resolving checkpatch issues
- use kzalloc_obj() (Manuel Ebner)
- add kernel-doc for the new mxl862xx_priv members
- trim comments and state the actual duration of a flash and reprobe cycle, just under a minute (Manuel Ebner)
- reword commit message: split up run-on sentence, explain the dynamically allocated reprobe work item (Manuel Ebner), mention that closing the ports stops phylib polling (Andrew Lunn)

 drivers/net/dsa/mxl862xx/Makefile        |   2 +-
 drivers/net/dsa/mxl862xx/mxl862xx-cmd.h  |   1 +
 drivers/net/dsa/mxl862xx/mxl862xx-fw.c   | 410 +++++++++++++++++++++++
 drivers/net/dsa/mxl862xx/mxl862xx-fw.h   |  15 +
 drivers/net/dsa/mxl862xx/mxl862xx-host.c |   7 +
 drivers/net/dsa/mxl862xx/mxl862xx.c      |   3 +
 drivers/net/dsa/mxl862xx/mxl862xx.h      |   6 +
 7 files changed, 443 insertions(+), 1 deletion(-)
 create mode 100644 drivers/net/dsa/mxl862xx/mxl862xx-fw.c
 create mode 100644 drivers/net/dsa/mxl862xx/mxl862xx-fw.h
drivers/net/dsa/mxl862xx/Makefile +1 -1
index a7be0e6669df..bccac0d0f703 100644
@@ -1,3 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_NET_DSA_MXL862) += mxl862xx_dsa.o
-mxl862xx_dsa-y := mxl862xx.o mxl862xx-host.o mxl862xx-phylink.o
+mxl862xx_dsa-y := mxl862xx.o mxl862xx-host.o mxl862xx-phylink.o mxl862xx-fw.o
drivers/net/dsa/mxl862xx/mxl862xx-cmd.h +1 -0
index c87a955c13c4..e2aa2934e9e1 100644
@@ -70,6 +70,7 @@
 #define INT_GPHY_READ			(GPY_GPY2XX_MAGIC + 0x1)
 #define INT_GPHY_WRITE			(GPY_GPY2XX_MAGIC + 0x2)
 
+#define SYS_MISC_FW_UPDATE		(SYS_MISC_MAGIC + 0x1)
 #define SYS_MISC_FW_VERSION		(SYS_MISC_MAGIC + 0x2)
 
 #define MXL862XX_XPCS_PCS_CONFIG	(MXL862XX_XPCS_MAGIC + 0x1)
drivers/net/dsa/mxl862xx/mxl862xx-fw.c new file +410 -0

410 lines not on this page · raw message

drivers/net/dsa/mxl862xx/mxl862xx-fw.h new file +15 -0
new file mode 100644
index 000000000000..a1b60fbacebf
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef __MXL862XX_FW_H
+#define __MXL862XX_FW_H
+
+#include <net/dsa.h>
+
+int mxl862xx_devlink_info_get(struct dsa_switch *ds,
+			      struct devlink_info_req *req,
+			      struct netlink_ext_ack *extack);
+int mxl862xx_devlink_flash_update(struct dsa_switch *ds,
+				  struct devlink_flash_update_params *params,
+				  struct netlink_ext_ack *extack);
+
+#endif /* __MXL862XX_FW_H */
drivers/net/dsa/mxl862xx/mxl862xx-host.c +7 -0
index 6e582caea1fa..7ba984e94d82 100644
@@ -15,6 +15,7 @@
 #include <linux/unaligned.h>
 #include <net/dsa.h>
 #include "mxl862xx.h"
+#include "mxl862xx-cmd.h"
 #include "mxl862xx-host.h"
 
 #define CTRL_BUSY_MASK			BIT(15)
@@ -336,6 +337,12 @@ int mxl862xx_api_wrap(struct mxl862xx_priv *priv, u16 cmd, void *_data,
 	int ret, cmd_ret;
 	u16 max, crc, i;
 
+	if (priv->skip_teardown)
+		return 0;
+
+	if (priv->block_host && cmd != SYS_MISC_FW_UPDATE)
+		return -EBUSY;
+
 	dev_dbg(&priv->mdiodev->dev, "CMD %04x DATA %*ph\n", cmd, size, data);
 
 	mutex_lock_nested(&priv->mdiodev->bus->mdio_lock, MDIO_MUTEX_NESTED);
drivers/net/dsa/mxl862xx/mxl862xx.c +3 -0
index 45d237b3a40f..e643083d3938 100644
@@ -21,6 +21,7 @@
 #include "mxl862xx.h"
 #include "mxl862xx-api.h"
 #include "mxl862xx-cmd.h"
+#include "mxl862xx-fw.h"
 #include "mxl862xx-host.h"
 #include "mxl862xx-phylink.h"
 
@@ -2086,6 +2087,8 @@ static const struct dsa_switch_ops mxl862xx_switch_ops = {
 	.get_pause_stats = mxl862xx_get_pause_stats,
 	.get_rmon_stats = mxl862xx_get_rmon_stats,
 	.get_stats64 = mxl862xx_get_stats64,
+	.devlink_info_get = mxl862xx_devlink_info_get,
+	.devlink_flash_update = mxl862xx_devlink_flash_update,
 };
 
 static int mxl862xx_probe(struct mdio_device *mdiodev)
drivers/net/dsa/mxl862xx/mxl862xx.h +6 -0
index 432a5f3f2e08..64d91ad51936 100644
@@ -319,6 +319,10 @@ struct mxl862xx_fw_version {
  * @evlan_ingress_size: per-port ingress Extended VLAN block size
  * @evlan_egress_size:  per-port egress Extended VLAN block size
  * @vf_block_size:      per-port VLAN Filter block size
+ * @block_host:         reject firmware API commands (except FW_UPDATE)
+ *                      during a firmware flash
+ * @skip_teardown:      discard firmware API commands during the teardown
+ *                      triggered by the post-flash reprobe
  * @stats_work:         periodic work item that polls RMON hardware counters
  *                      and accumulates them into 64-bit per-port stats
  */
@@ -337,6 +341,8 @@ struct mxl862xx_priv {
 	u16 evlan_ingress_size;
 	u16 evlan_egress_size;
 	u16 vf_block_size;
+	bool block_host;
+	bool skip_teardown;
 	struct delayed_work stats_work;
 };
 
Signature · 1 line
2.55.0
author maintainer
#4 lore raw

Re: [PATCH net-next v2 3/4] net: dsa: mxl862xx: add devlink flash_update and info_get

On Tue, Jul 14, 2026 at 01:51:02AM +0100, Daniel Golle wrote:
[...]

drivers/net/dsa/mxl862xx/mxl862xx-fw.c line 326

Quoted 5 lines
drivers/net/dsa/mxl862xx/mxl862xx-fw.c new file +5 -0
+	if (!of_property_read_string_index(ds->dev->of_node, "compatible", 0,
+					   &compatible)) {
+		ret = devlink_info_version_fixed_put(req,
+						     DEVLINK_INFO_VERSION_GENERIC_ASIC_ID,
+						     compatible);

Review of the fwupd counterpart of this series[1] made me reconsider what the driver reports as the "asic.id" fixed version. The devicetree compatible string used here ("maxlinear,mxl86252") turned out to be an unfortunate choice as the comma is awkward for userspace consumers, so for v3 I plan to follow the mv88e6xxx example and report a chip name from a per-model info table instead:

fixed:
asic.id MaxLinear MxL86252

Before sending v3 I would like to clarify the preferred format of the value. Existing implementations differ: mv88e6xxx reports for example "Marvell 88E6085", including the vendor name and a space, sja1105 reports "SJA1105E", hellcreek reports "hellcreek", and bnxt and ionic report bare chip identifiers.

Documentation/networking/devlink/devlink-info.rst only describes "asic.id" as "ASIC design identifier" without any format constraints.

Userspace builds firmware matching identifiers from these values, in the case of fwupd for example

MDIO_BUS\COMPONENT_fw&ASIC.ID_MaxLinear MxL86252

and while a space works there, such identifiers commonly avoid spaces in favour of underscores, hyphens or dots.

Is there a preference for new drivers? Should the vendor name be part of "asic.id" as done by mv88e6xxx, or would a single token such as "MxL86252" be more appropriate?

[1] https://github.com/fwupd/fwupd/pull/10667

maintainer
#5 lore raw

Re: [PATCH net-next v2 3/4] net: dsa: mxl862xx: add devlink flash_update and info_get

Quoted 30 lines · Daniel Golle

On Tue, Jul 14, 2026 at 01:51:02AM +0100, Daniel Golle wrote:
[...]

drivers/net/dsa/mxl862xx/mxl862xx-fw.c line 326

Quoted 5 lines
drivers/net/dsa/mxl862xx/mxl862xx-fw.c new file +5 -0
+	if (!of_property_read_string_index(ds->dev->of_node, "compatible", 0,
+					   &compatible)) {
+		ret = devlink_info_version_fixed_put(req,
+						     DEVLINK_INFO_VERSION_GENERIC_ASIC_ID,
+						     compatible);

Review of the fwupd counterpart of this series[1] made me reconsider what the driver reports as the "asic.id" fixed version. The devicetree compatible string used here ("maxlinear,mxl86252") turned out to be an unfortunate choice as the comma is awkward for userspace consumers, so for v3 I plan to follow the mv88e6xxx example and report a chip name from a per-model info table instead:

fixed:
asic.id MaxLinear MxL86252

Before sending v3 I would like to clarify the preferred format of the value. Existing implementations differ: mv88e6xxx reports for example "Marvell 88E6085", including the vendor name and a space, sja1105 reports "SJA1105E", hellcreek reports "hellcreek", and bnxt and ionic report bare chip identifiers.

Documentation/networking/devlink/devlink-info.rst only describes "asic.id" as "ASIC design identifier" without any format constraints.

Userspace builds firmware matching identifiers from these values, in the case of fwupd for example

Quoted 8 lines

MDIO_BUS\COMPONENT_fw&ASIC.ID_MaxLinear MxL86252

and while a space works there, such identifiers commonly avoid spaces in favour of underscores, hyphens or dots.

Is there a preference for new drivers? Should the vendor name be part of "asic.id" as done by mv88e6xxx, or would a single token such as "MxL86252" be more appropriate?

I would say it is a Wild West, and you can put anything sensible here.

Andrew

maintainer
#6 lore raw

Re: [PATCH net-next v2 3/4] net: dsa: mxl862xx: add devlink flash_update and info_get

In reply to Daniel Golle
Quoted 32 lines · On Tue, 14 Jul 2026 20:14:56 +0100 Daniel Golle wrote:

On Tue, Jul 14, 2026 at 01:51:02AM +0100, Daniel Golle wrote:
[...]

drivers/net/dsa/mxl862xx/mxl862xx-fw.c line 326

Quoted 5 lines
drivers/net/dsa/mxl862xx/mxl862xx-fw.c new file +5 -0
+	if (!of_property_read_string_index(ds->dev->of_node, "compatible", 0,
+					   &compatible)) {
+		ret = devlink_info_version_fixed_put(req,
+						     DEVLINK_INFO_VERSION_GENERIC_ASIC_ID,
+						     compatible);  

Review of the fwupd counterpart of this series[1] made me reconsider what the driver reports as the "asic.id" fixed version. The devicetree compatible string used here ("maxlinear,mxl86252") turned out to be an unfortunate choice as the comma is awkward for userspace consumers, so for v3 I plan to follow the mv88e6xxx example and report a chip name from a per-model info table instead:

fixed:
asic.id MaxLinear MxL86252

Before sending v3 I would like to clarify the preferred format of the value. Existing implementations differ: mv88e6xxx reports for example "Marvell 88E6085", including the vendor name and a space, sja1105 reports "SJA1105E", hellcreek reports "hellcreek", and bnxt and ionic report bare chip identifiers.

Documentation/networking/devlink/devlink-info.rst only describes "asic.id" as "ASIC design identifier" without any format constraints.

Userspace builds firmware matching identifiers from these values, in the case of fwupd for example

MDIO_BUS\COMPONENT_fw&ASIC.ID_MaxLinear MxL86252

Quoted 8 lines

and while a space works there, such identifiers commonly avoid spaces in favour of underscores, hyphens or dots.

Is there a preference for new drivers? Should the vendor name be part of "asic.id" as done by mv88e6xxx, or would a single token such as "MxL86252" be more appropriate?

[1] https://github.com/fwupd/fwupd/pull/10667

The embedded drivers are probably doing it wrong, I wasn't paying enough attention. devlink versions are supposed to be broken up into components, the vendor name does not belong in asic id.

IIUC asic.id was supposed to be the numerical version of the design (excluding revision, which is asic.rev). Something that's usually read from a static CSR.

author maintainer
#7 lore raw

PATCH v2 4/4 net: dsa: mxl862xx: recover switch stuck in MCUboot rescue mode

In reply to Daniel Golle

When the application firmware image is broken (e.g. after an interrupted flash update) or the sticky rescue flag is set, the switch stays in MCUboot which only exposes the clause-22 SMDIO interface used for firmware download. The clause-45 MMD API never becomes ready, probe fails with -ETIMEDOUT and the user is left without any way to install a working firmware image other than physical access to the UART console of the switch.

Detect this state during setup by reading the SB PDI STAT register via SMDIO: MCUboot signals readiness for a firmware download with the ready magic. Probe this register first to avoid pointlessly waiting for the MMD API on a switch sitting in rescue mode, and probe it again after a ready timeout to catch firmware which was still alive enough to accept the reset command but then fell into rescue mode due to a broken image on flash.

In rescue mode, complete the switch registration without any user interfaces so that devlink is available: user ports fail port_setup with -ENODEV which makes the DSA core re-register them as unused ports, while shared and unused ports succeed as their setup must not fail for the tree to register. The CPU port works without firmware access since it uses a fixed link and the phylink MAC ops do not touch the hardware; mac_select_pcs returns no PCS in rescue mode. Firmware API commands fail fast with -ENODEV instead of running into the MDIO poll timeout, and the port enable/disable and STP callbacks invoked by the DSA core during registration and teardown become no-ops.

devlink dev info reports the running firmware version as "mcuboot-rescue" so the state can be told apart from an operational switch. devlink flash update skips the FW_UPDATE command in rescue mode as MCUboot is already waiting for a download, and proceeds directly with the SB PDI handshake. After a successful transfer the usual reprobe cycle restores normal operation; after a failed one rescue mode is detected again and the user can simply retry.

---
v2: new patch, allowing recovery from a failed or interrupted update
without physical access to the switch (Andrew Lunn)

 drivers/net/dsa/mxl862xx/mxl862xx-fw.c      | 49 ++++++++++++++++-----
 drivers/net/dsa/mxl862xx/mxl862xx-fw.h      |  3 ++
 drivers/net/dsa/mxl862xx/mxl862xx-host.c    |  3 ++
 drivers/net/dsa/mxl862xx/mxl862xx-phylink.c |  2 +
 drivers/net/dsa/mxl862xx/mxl862xx.c         | 38 ++++++++++++++--
 drivers/net/dsa/mxl862xx/mxl862xx.h         |  3 ++
 6 files changed, 85 insertions(+), 13 deletions(-)
drivers/net/dsa/mxl862xx/mxl862xx-fw.c +39 -10
index b2c23ccf1370..88d53bea336f 100644
@@ -92,6 +92,24 @@ static void mxl862xx_flash_notify(struct devlink *dl, const char *status,
 	devlink_flash_update_status_notify(dl, status, NULL, done, total);
 }
 
+/**
+ * mxl862xx_rescue_mode_detect - check whether the switch sits in MCUboot
+ * @priv: driver private data
+ *
+ * MCUboot signals readiness for a firmware download with the SB PDI
+ * ready magic; only the clause-22 SMDIO interface works in this state.
+ *
+ * Return: true if MCUboot is waiting for a firmware download.
+ */
+bool mxl862xx_rescue_mode_detect(struct mxl862xx_priv *priv)
+{
+	int ret;
+
+	ret = mxl862xx_smdio_read(priv, MXL862XX_SB_PDI_STAT);
+
+	return ret == MXL862XX_SB_PDI_READY;
+}
+
 /* device_reprobe() -> remove() frees priv while the work runs, so
  * the work struct cannot live in mxl862xx_priv.
  */
@@ -172,13 +190,15 @@ static int mxl862xx_flash_firmware(struct mxl862xx_priv *priv,
 	}
 
 	/* Step 1: reboot the firmware into MCUboot rescue mode */
-	ret = mxl862xx_api_wrap(priv, SYS_MISC_FW_UPDATE, NULL, 0,
-				false, false);
-	if (ret) {
-		dev_err(&priv->mdiodev->dev,
-			"flash: FW_UPDATE command failed: %pe\n",
-			ERR_PTR(ret));
-		return ret;
+	if (!priv->rescue_mode) {
+		ret = mxl862xx_api_wrap(priv, SYS_MISC_FW_UPDATE, NULL, 0,
+					false, false);
+		if (ret) {
+			dev_err(&priv->mdiodev->dev,
+				"flash: FW_UPDATE command failed: %pe\n",
+				ERR_PTR(ret));
+			return ret;
+		}
 	}
 
 	/* Failures from here on must go through end_magic so MCUboot
@@ -328,6 +348,10 @@ int mxl862xx_devlink_info_get(struct dsa_switch *ds,
 			return ret;
 	}
 
+	if (priv->rescue_mode)
+		return devlink_info_version_running_put(req, "fw",
+							"mcuboot-rescue");
+
 	snprintf(ver_str, sizeof(ver_str), "%u.%u.%u",
 		 priv->fw_version.major, priv->fw_version.minor,
 		 priv->fw_version.revision);
@@ -350,9 +374,13 @@ int mxl862xx_devlink_flash_update(struct dsa_switch *ds,
 		return -EOPNOTSUPP;
 	}
 
-	dev_info(ds->dev, "flash: running firmware %u.%u.%u\n",
-		 priv->fw_version.major, priv->fw_version.minor,
-		 priv->fw_version.revision);
+	if (priv->rescue_mode)
+		dev_info(ds->dev,
+			 "flash: recovering switch from MCUboot rescue mode\n");
+	else
+		dev_info(ds->dev, "flash: running firmware %u.%u.%u\n",
+			 priv->fw_version.major, priv->fw_version.minor,
+			 priv->fw_version.revision);
 
 	/* Close ports while the firmware is still alive so the DSA
 	 * core's MDB/FDB tracking is drained, and detach user ports
@@ -383,6 +411,7 @@ int mxl862xx_devlink_flash_update(struct dsa_switch *ds,
 	if (!ret) {
 		/* lift the block to query the new firmware version */
 		priv->block_host = false;
+		priv->rescue_mode = false;
 		memset(&ver, 0, sizeof(ver));
 		if (!MXL862XX_API_READ_QUIET(priv, SYS_MISC_FW_VERSION, ver) &&
 		    ver.iv_major)
drivers/net/dsa/mxl862xx/mxl862xx-fw.h +3 -0
index a1b60fbacebf..57c2000cfee5 100644
@@ -5,6 +5,9 @@
 
 #include <net/dsa.h>
 
+struct mxl862xx_priv;
+
+bool mxl862xx_rescue_mode_detect(struct mxl862xx_priv *priv);
 int mxl862xx_devlink_info_get(struct dsa_switch *ds,
 			      struct devlink_info_req *req,
 			      struct netlink_ext_ack *extack);
drivers/net/dsa/mxl862xx/mxl862xx-host.c +3 -0
index 7ba984e94d82..d6c0cdfa0e68 100644
@@ -340,6 +340,9 @@ int mxl862xx_api_wrap(struct mxl862xx_priv *priv, u16 cmd, void *_data,
 	if (priv->skip_teardown)
 		return 0;
 
+	if (priv->rescue_mode)
+		return -ENODEV;
+
 	if (priv->block_host && cmd != SYS_MISC_FW_UPDATE)
 		return -EBUSY;
 
drivers/net/dsa/mxl862xx/mxl862xx-phylink.c +2 -0
index b689652aa9b9..a5b6940b552e 100644
@@ -406,6 +406,8 @@ mxl862xx_phylink_mac_select_pcs(struct phylink_config *config,
 
 	switch (port) {
 	case 9 ... 16:
+		if (priv->rescue_mode)
+			return NULL;
 		if (!MXL862XX_FW_VER_MIN(priv, 1, 0, 84)) {
 			dev_warn_once(dp->ds->dev,
 				      "SerDes PCS unsupported on old firmware.\n");
drivers/net/dsa/mxl862xx/mxl862xx.c +35 -3
index e643083d3938..b7385cfa5474 100644
@@ -629,9 +629,22 @@ static int mxl862xx_setup(struct dsa_switch *ds)
 	if (ret)
 		return ret;
 
-	ret = mxl862xx_wait_ready(ds);
-	if (ret)
-		return ret;
+	priv->rescue_mode = mxl862xx_rescue_mode_detect(priv);
+	if (!priv->rescue_mode) {
+		ret = mxl862xx_wait_ready(ds);
+		if (ret) {
+			/* the reset may only now have triggered rescue mode */
+			priv->rescue_mode = mxl862xx_rescue_mode_detect(priv);
+			if (!priv->rescue_mode)
+				return ret;
+		}
+	}
+
+	if (priv->rescue_mode) {
+		dev_warn(ds->dev,
+			 "switch stuck in MCUboot rescue mode, use devlink to flash new firmware\n");
+		return 0;
+	}
 
 	mutex_init(&priv->serdes_lock);
 	for (i = 0; i < ARRAY_SIZE(priv->serdes_ports); i++)
@@ -716,11 +729,21 @@ static int mxl862xx_port_state(struct dsa_switch *ds, int port, bool enable)
 static int mxl862xx_port_enable(struct dsa_switch *ds, int port,
 				struct phy_device *phydev)
 {
+	struct mxl862xx_priv *priv = ds->priv;
+
+	if (priv->rescue_mode)
+		return 0;
+
 	return mxl862xx_port_state(ds, port, true);
 }
 
 static void mxl862xx_port_disable(struct dsa_switch *ds, int port)
 {
+	struct mxl862xx_priv *priv = ds->priv;
+
+	if (priv->rescue_mode)
+		return;
+
 	if (mxl862xx_port_state(ds, port, false))
 		dev_err(ds->dev, "failed to disable port %d\n", port);
 }
@@ -1338,6 +1361,12 @@ static int mxl862xx_port_setup(struct dsa_switch *ds, int port)
 	bool is_cpu_port = dsa_port_is_cpu(dp);
 	int ret;
 
+	/* DSA reinits failed user ports as unused; shared ports must
+	 * succeed for the tree to register.
+	 */
+	if (priv->rescue_mode)
+		return dsa_port_is_user(dp) ? -ENODEV : 0;
+
 	ret = mxl862xx_port_state(ds, port, false);
 	if (ret)
 		return ret;
@@ -1629,6 +1658,9 @@ static void mxl862xx_port_stp_state_set(struct dsa_switch *ds, int port,
 	struct mxl862xx_priv *priv = ds->priv;
 	int ret;
 
+	if (priv->rescue_mode)
+		return;
+
 	switch (state) {
 	case BR_STATE_DISABLED:
 		param.port_state = cpu_to_le32(MXL862XX_STP_PORT_STATE_DISABLE);
drivers/net/dsa/mxl862xx/mxl862xx.h +3 -0
index 64d91ad51936..5d21296561e3 100644
@@ -323,6 +323,8 @@ struct mxl862xx_fw_version {
  *                      during a firmware flash
  * @skip_teardown:      discard firmware API commands during the teardown
  *                      triggered by the post-flash reprobe
+ * @rescue_mode:        switch is stuck in MCUboot; firmware API commands
+ *                      fail fast, only clause-22 SMDIO works
  * @stats_work:         periodic work item that polls RMON hardware counters
  *                      and accumulates them into 64-bit per-port stats
  */
@@ -343,6 +345,7 @@ struct mxl862xx_priv {
 	u16 vf_block_size;
 	bool block_host;
 	bool skip_teardown;
+	bool rescue_mode;
 	struct delayed_work stats_work;
 };
 
Signature · 1 line
2.55.0