net: dsa: microchip: fix DCB apptrust configuration on KSZ88x3

Remove KSZ88x3-specific priority and apptrust configuration logic that was
based on incorrect register access assumptions. Also fix the register
offset for KSZ8_REG_PORT_1_CTRL_0 to align with get_port_addr() logic.

The KSZ88x3 switch family uses a different register layout compared to
KSZ9477-compatible variants. Specifically, port control registers need
offset adjustment through get_port_addr(), and do not match the datasheet
values directly.

Commit a1ea57710c9d ("net: dsa: microchip: dcb: add special handling for
KSZ88X3 family") introduced quirks based on datasheet offsets, which do
not work with the driver's internal addressing model. As a result, these
quirks addressed the wrong ports and caused unstable behavior.

This patch removes all KSZ88x3-specific DCB quirks and corrects the port
control register offset, effectively restoring working and predictable
apptrust configuration.

Fixes: a1ea57710c9d ("net: dsa: microchip: dcb: add special handling for KSZ88X3 family")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250321141044.2128973-1-o.rempel@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/dsa/microchip/ksz8.c b/drivers/net/dsa/microchip/ksz8.c
index da7110d675583dfb7c9be876d5ec5d12cddcf9b4..be433b4e2b1ca8f10a97b3dc47ebdc28017e602f 100644 (file)
--- a/drivers/net/dsa/microchip/ksz8.c
+++ b/drivers/net/dsa/microchip/ksz8.c
@@ -1625,7 +1625,6 @@ void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
        const u16 *regs = dev->info->regs;
        struct dsa_switch *ds = dev->ds;
        const u32 *masks;
-       int queues;
        u8 member;
 
        masks = dev->info->masks;
@@ -1633,15 +1632,7 @@ void ksz8_port_setup(struct ksz_device *dev, int port, bool cpu_port)
        /* enable broadcast storm limit */
        ksz_port_cfg(dev, port, P_BCAST_STORM_CTRL, PORT_BROADCAST_STORM, true);
 
-       /* For KSZ88x3 enable only one queue by default, otherwise we won't
-        * be able to get rid of PCP prios on Port 2.
-        */
-       if (ksz_is_ksz88x3(dev))
-               queues = 1;
-       else
-               queues = dev->info->num_tx_queues;
-
-       ksz8_port_queue_split(dev, port, queues);
+       ksz8_port_queue_split(dev, port, dev->info->num_tx_queues);
 
        /* replace priority */
        ksz_port_cfg(dev, port, P_802_1P_CTRL,

diff --git a/drivers/net/dsa/microchip/ksz_dcb.c b/drivers/net/dsa/microchip/ksz_dcb.c
index 30b4a6186e38f43099c7ff503cf9a53bcc1b4909..c3b501997ac948f3da02c96ee9af7cc5d35de81b 100644 (file)
--- a/drivers/net/dsa/microchip/ksz_dcb.c
+++ b/drivers/net/dsa/microchip/ksz_dcb.c
@@ -10,7 +10,12 @@
 #include "ksz_dcb.h"
 #include "ksz8.h"
 
-#define KSZ8_REG_PORT_1_CTRL_0                 0x10
+/* Port X Control 0 register.
+ * The datasheet specifies: Port 1 - 0x10, Port 2 - 0x20, Port 3 - 0x30.
+ * However, the driver uses get_port_addr(), which maps Port 1 to offset 0.
+ * Therefore, we define the base offset as 0x00 here to align with that logic.
+ */
+#define KSZ8_REG_PORT_1_CTRL_0                 0x00
 #define KSZ8_PORT_DIFFSERV_ENABLE              BIT(6)
 #define KSZ8_PORT_802_1P_ENABLE                        BIT(5)
 #define KSZ8_PORT_BASED_PRIO_M                 GENMASK(4, 3)
@@ -181,49 +186,6 @@ int ksz_port_get_default_prio(struct dsa_switch *ds, int port)
        return (data & mask) >> shift;
 }
 
-/**
- * ksz88x3_port_set_default_prio_quirks - Quirks for default priority
- * @dev: Pointer to the KSZ switch device structure
- * @port: Port number for which to set the default priority
- * @prio: Priority value to set
- *
- * This function implements quirks for setting the default priority on KSZ88x3
- * devices. On Port 2, no other priority providers are working
- * except of PCP. So, configuring default priority on Port 2 is not possible.
- * On Port 1, it is not possible to configure port priority if PCP
- * apptrust on Port 2 is disabled. Since we disable multiple queues on the
- * switch to disable PCP on Port 2, we need to ensure that the default priority
- * configuration on Port 1 is in agreement with the configuration on Port 2.
- *
- * Return: 0 on success, or a negative error code on failure
- */
-static int ksz88x3_port_set_default_prio_quirks(struct ksz_device *dev, int port,
-                                               u8 prio)
-{
-       if (!prio)
-               return 0;
-
-       if (port == KSZ_PORT_2) {
-               dev_err(dev->dev, "Port priority configuration is not working on Port 2\n");
-               return -EINVAL;
-       } else if (port == KSZ_PORT_1) {
-               u8 port2_data;
-               int ret;
-
-               ret = ksz_pread8(dev, KSZ_PORT_2, KSZ8_REG_PORT_1_CTRL_0,
-                                &port2_data);
-               if (ret)
-                       return ret;
-
-               if (!(port2_data & KSZ8_PORT_802_1P_ENABLE)) {
-                       dev_err(dev->dev, "Not possible to configure port priority on Port 1 if PCP apptrust on Port 2 is disabled\n");
-                       return -EINVAL;
-               }
-       }
-
-       return 0;
-}
-
 /**
  * ksz_port_set_default_prio - Sets the default priority for a port on a KSZ
  *                            switch
@@ -239,18 +201,12 @@ static int ksz88x3_port_set_default_prio_quirks(struct ksz_device *dev, int port
 int ksz_port_set_default_prio(struct dsa_switch *ds, int port, u8 prio)
 {
        struct ksz_device *dev = ds->priv;
-       int reg, shift, ret;
+       int reg, shift;
        u8 mask;
 
        if (prio >= dev->info->num_ipms)
                return -EINVAL;
 
-       if (ksz_is_ksz88x3(dev)) {
-               ret = ksz88x3_port_set_default_prio_quirks(dev, port, prio);
-               if (ret)
-                       return ret;
-       }
-
        ksz_get_default_port_prio_reg(dev, &reg, &mask, &shift);
 
        return ksz_prmw8(dev, port, reg, mask, (prio << shift) & mask);
@@ -518,155 +474,6 @@ err_sel_not_vaild:
        return -EINVAL;
 }
 
-/**
- * ksz88x3_port1_apptrust_quirk - Quirk for apptrust configuration on Port 1
- *                               of KSZ88x3 devices
- * @dev: Pointer to the KSZ switch device structure
- * @port: Port number for which to set the apptrust selectors
- * @reg: Register address for the apptrust configuration
- * @port1_data: Data to set for the apptrust configuration
- *
- * This function implements a quirk for apptrust configuration on Port 1 of
- * KSZ88x3 devices. It ensures that apptrust configuration on Port 1 is not
- * possible if PCP apptrust on Port 2 is disabled. This is because the Port 2
- * seems to be permanently hardwired to PCP classification, so we need to
- * do Port 1 configuration always in agreement with Port 2 configuration.
- *
- * Return: 0 on success, or a negative error code on failure
- */
-static int ksz88x3_port1_apptrust_quirk(struct ksz_device *dev, int port,
-                                       int reg, u8 port1_data)
-{
-       u8 port2_data;
-       int ret;
-
-       /* If no apptrust is requested for Port 1, no need to care about Port 2
-        * configuration.
-        */
-       if (!(port1_data & (KSZ8_PORT_802_1P_ENABLE | KSZ8_PORT_DIFFSERV_ENABLE)))
-               return 0;
-
-       /* We got request to enable any apptrust on Port 1. To make it possible,
-        * we need to enable multiple queues on the switch. If we enable
-        * multiqueue support, PCP classification on Port 2 will be
-        * automatically activated by HW.
-        */
-       ret = ksz_pread8(dev, KSZ_PORT_2, reg, &port2_data);
-       if (ret)
-               return ret;
-
-       /* If KSZ8_PORT_802_1P_ENABLE bit is set on Port 2, the driver showed
-        * the interest in PCP classification on Port 2. In this case,
-        * multiqueue support is enabled and we can enable any apptrust on
-        * Port 1.
-        * If KSZ8_PORT_802_1P_ENABLE bit is not set on Port 2, the PCP
-        * classification on Port 2 is still active, but the driver disabled
-        * multiqueue support and made frame prioritization inactive for
-        * all ports. In this case, we can't enable any apptrust on Port 1.
-        */
-       if (!(port2_data & KSZ8_PORT_802_1P_ENABLE)) {
-               dev_err(dev->dev, "Not possible to enable any apptrust on Port 1 if PCP apptrust on Port 2 is disabled\n");
-               return -EINVAL;
-       }
-
-       return 0;
-}
-
-/**
- * ksz88x3_port2_apptrust_quirk - Quirk for apptrust configuration on Port 2
- *                               of KSZ88x3 devices
- * @dev: Pointer to the KSZ switch device structure
- * @port: Port number for which to set the apptrust selectors
- * @reg: Register address for the apptrust configuration
- * @port2_data: Data to set for the apptrust configuration
- *
- * This function implements a quirk for apptrust configuration on Port 2 of
- * KSZ88x3 devices. It ensures that DSCP apptrust is not working on Port 2 and
- * that it is not possible to disable PCP on Port 2. The only way to disable PCP
- * on Port 2 is to disable multiple queues on the switch.
- *
- * Return: 0 on success, or a negative error code on failure
- */
-static int ksz88x3_port2_apptrust_quirk(struct ksz_device *dev, int port,
-                                       int reg, u8 port2_data)
-{
-       struct dsa_switch *ds = dev->ds;
-       u8 port1_data;
-       int ret;
-
-       /* First validate Port 2 configuration. DiffServ/DSCP is not working
-        * on this port.
-        */
-       if (port2_data & KSZ8_PORT_DIFFSERV_ENABLE) {
-               dev_err(dev->dev, "DSCP apptrust is not working on Port 2\n");
-               return -EINVAL;
-       }
-
-       /* If PCP support is requested, we need to enable all queues on the
-        * switch to make PCP priority working on Port 2.
-        */
-       if (port2_data & KSZ8_PORT_802_1P_ENABLE)
-               return ksz8_all_queues_split(dev, dev->info->num_tx_queues);
-
-       /* We got request to disable PCP priority on Port 2.
-        * Now, we need to compare Port 2 configuration with Port 1
-        * configuration.
-        */
-       ret = ksz_pread8(dev, KSZ_PORT_1, reg, &port1_data);
-       if (ret)
-               return ret;
-
-       /* If Port 1 has any apptrust enabled, we can't disable multiple queues
-        * on the switch, so we can't disable PCP on Port 2.
-        */
-       if (port1_data & (KSZ8_PORT_802_1P_ENABLE | KSZ8_PORT_DIFFSERV_ENABLE)) {
-               dev_err(dev->dev, "Not possible to disable PCP on Port 2 if any apptrust is enabled on Port 1\n");
-               return -EINVAL;
-       }
-
-       /* Now we need to ensure that default priority on Port 1 is set to 0
-        * otherwise we can't disable multiqueue support on the switch.
-        */
-       ret = ksz_port_get_default_prio(ds, KSZ_PORT_1);
-       if (ret < 0) {
-               return ret;
-       } else if (ret) {
-               dev_err(dev->dev, "Not possible to disable PCP on Port 2 if non zero default priority is set on Port 1\n");
-               return -EINVAL;
-       }
-
-       /* Port 1 has no apptrust or default priority set and we got request to
-        * disable PCP on Port 2. We can disable multiqueue support to disable
-        * PCP on Port 2.
-        */
-       return ksz8_all_queues_split(dev, 1);
-}
-
-/**
- * ksz88x3_port_apptrust_quirk - Quirk for apptrust configuration on KSZ88x3
- *                            devices
- * @dev: Pointer to the KSZ switch device structure
- * @port: Port number for which to set the apptrust selectors
- * @reg: Register address for the apptrust configuration
- * @data: Data to set for the apptrust configuration
- *
- * This function implements a quirk for apptrust configuration on KSZ88x3
- * devices. It ensures that apptrust configuration on Port 1 and
- * Port 2 is done in agreement with each other.
- *
- * Return: 0 on success, or a negative error code on failure
- */
-static int ksz88x3_port_apptrust_quirk(struct ksz_device *dev, int port,
-                                      int reg, u8 data)
-{
-       if (port == KSZ_PORT_1)
-               return ksz88x3_port1_apptrust_quirk(dev, port, reg, data);
-       else if (port == KSZ_PORT_2)
-               return ksz88x3_port2_apptrust_quirk(dev, port, reg, data);
-
-       return 0;
-}
-
 /**
  * ksz_port_set_apptrust - Sets the apptrust selectors for a port on a KSZ
  *                        switch
@@ -707,12 +514,6 @@ int ksz_port_set_apptrust(struct dsa_switch *ds, int port,
                }
        }
 
-       if (ksz_is_ksz88x3(dev)) {
-               ret = ksz88x3_port_apptrust_quirk(dev, port, reg, data);
-               if (ret)
-                       return ret;
-       }
-
        return ksz_prmw8(dev, port, reg, mask, data);
 }
 
@@ -799,21 +600,5 @@ int ksz_dcb_init_port(struct ksz_device *dev, int port)
  */
 int ksz_dcb_init(struct ksz_device *dev)
 {
-       int ret;
-
-       ret = ksz_init_global_dscp_map(dev);
-       if (ret)
-               return ret;
-
-       /* Enable 802.1p priority control on Port 2 during switch initialization.
-        * This setup is critical for the apptrust functionality on Port 1, which
-        * relies on the priority settings of Port 2. Note: Port 1 is naturally
-        * configured before Port 2, necessitating this configuration order.
-        */
-       if (ksz_is_ksz88x3(dev))
-               return ksz_prmw8(dev, KSZ_PORT_2, KSZ8_REG_PORT_1_CTRL_0,
-                                KSZ8_PORT_802_1P_ENABLE,
-                                KSZ8_PORT_802_1P_ENABLE);
-
-       return 0;
+       return ksz_init_global_dscp_map(dev);
 }