From: Russell King <rmk+kernel@armlinux.org.uk>
To: Andrew Lunn <andrew@lunn.ch>, Heiner Kallweit <hkallweit1@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>
Subject: [PATCH net-next] net: sfp: add debugfs support
Date: Mon, 23 Nov 2020 22:06:16 +0000 [thread overview]
Message-ID: <E1khJyS-0003UU-9O@rmk-PC.armlinux.org.uk> (raw)
Add debugfs support to SFP so that the internal state of the SFP state
machines and hardware signal state can be viewed from userspace, rather
than having to compile a debug kernel to view state state transitions
in the kernel log. The 'state' output looks like:
Module state: empty
Module probe attempts: 0 0
Device state: up
Main state: down
Fault recovery remaining retries: 5
PHY probe remaining retries: 12
moddef0: 0
rx_los: 1
tx_fault: 1
tx_disable: 1
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
This is useful to view the state of the SFP cage when e.g., debugging
a module that the link doesn't seem to be coming up for. Rather than
sending this patch each time there is a query, it seems sensible to
merge it into mainline instead.
drivers/net/phy/sfp.c | 55 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c
index 1e347afa951e..2c32aa891f17 100644
--- a/drivers/net/phy/sfp.c
+++ b/drivers/net/phy/sfp.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/acpi.h>
#include <linux/ctype.h>
+#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/hwmon.h>
@@ -258,6 +259,9 @@ struct sfp {
char *hwmon_name;
#endif
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+ struct dentry *debugfs_dir;
+#endif
};
static bool sff_module_supported(const struct sfp_eeprom_id *id)
@@ -1390,6 +1394,54 @@ static void sfp_module_tx_enable(struct sfp *sfp)
sfp_set_state(sfp, sfp->state);
}
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+static int sfp_debug_state_show(struct seq_file *s, void *data)
+{
+ struct sfp *sfp = s->private;
+
+ seq_printf(s, "Module state: %s\n",
+ mod_state_to_str(sfp->sm_mod_state));
+ seq_printf(s, "Module probe attempts: %d %d\n",
+ R_PROBE_RETRY_INIT - sfp->sm_mod_tries_init,
+ R_PROBE_RETRY_SLOW - sfp->sm_mod_tries);
+ seq_printf(s, "Device state: %s\n",
+ dev_state_to_str(sfp->sm_dev_state));
+ seq_printf(s, "Main state: %s\n",
+ sm_state_to_str(sfp->sm_state));
+ seq_printf(s, "Fault recovery remaining retries: %d\n",
+ sfp->sm_fault_retries);
+ seq_printf(s, "PHY probe remaining retries: %d\n",
+ sfp->sm_phy_retries);
+ seq_printf(s, "moddef0: %d\n", !!(sfp->state & SFP_F_PRESENT));
+ seq_printf(s, "rx_los: %d\n", !!(sfp->state & SFP_F_LOS));
+ seq_printf(s, "tx_fault: %d\n", !!(sfp->state & SFP_F_TX_FAULT));
+ seq_printf(s, "tx_disable: %d\n", !!(sfp->state & SFP_F_TX_DISABLE));
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(sfp_debug_state);
+
+static void sfp_debugfs_init(struct sfp *sfp)
+{
+ sfp->debugfs_dir = debugfs_create_dir(dev_name(sfp->dev), NULL);
+
+ debugfs_create_file("state", 0600, sfp->debugfs_dir, sfp,
+ &sfp_debug_state_fops);
+}
+
+static void sfp_debugfs_exit(struct sfp *sfp)
+{
+ debugfs_remove_recursive(sfp->debugfs_dir);
+}
+#else
+static void sfp_debugfs_init(struct sfp *sfp)
+{
+}
+
+static void sfp_debugfs_exit(struct sfp *sfp)
+{
+}
+#endif
+
static void sfp_module_tx_fault_reset(struct sfp *sfp)
{
unsigned int state = sfp->state;
@@ -2472,6 +2524,8 @@ static int sfp_probe(struct platform_device *pdev)
return -ENOMEM;
}
+ sfp_debugfs_init(sfp);
+
return 0;
}
@@ -2479,6 +2533,7 @@ static int sfp_remove(struct platform_device *pdev)
{
struct sfp *sfp = platform_get_drvdata(pdev);
+ sfp_debugfs_exit(sfp);
sfp_unregister_socket(sfp->sfp_bus);
rtnl_lock();
--
2.20.1
next reply other threads:[~2020-11-23 22:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-23 22:06 Russell King [this message]
2020-11-24 0:14 ` [PATCH net-next] net: sfp: add debugfs support Andrew Lunn
2020-11-24 8:41 ` Ido Schimmel
2020-11-24 9:49 ` Russell King - ARM Linux admin
2020-11-24 10:46 ` Ido Schimmel
2020-12-02 13:03 ` Russell King - ARM Linux admin
2020-12-02 16:59 ` Jakub Kicinski
2020-12-02 17:01 ` Jakub Kicinski
2020-12-07 16:06 ` Russell King - ARM Linux admin
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