From f83a052f9a0b62318d4f6e9bdddf9fc0103ac908 Mon Sep 17 00:00:00 2001
From: Adam Goldman <adamg@pobox.com>
Date: Mon, 25 Mar 2024 07:37:25 +0900
Subject: [PATCH] firewire: core: option to log bus reset initiation
Add a debug parameter to firewire-core, analogous to the one in
firewire-ohci. When this is set to 1, log when we schedule, delay, or
initiate a bus reset. Since FireWire bus resets can originate from any
node on the bus, specific logging of the resets we initiate provides
additional insight.
Signed-off-by: Adam Goldman <adamg@pobox.com>
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
drivers/firewire/core-card.c | 10 ++++++++++
drivers/firewire/core-transaction.c | 7 +++++++
drivers/firewire/core.h | 4 ++++
3 files changed, 21 insertions(+)
diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 401a77e3b5fa8..dac1b0fc7a428 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -221,11 +221,19 @@ static int reset_bus(struct fw_card *card, bool short_reset)
int reg = short_reset ? 5 : 1;
int bit = short_reset ? PHY_BUS_SHORT_RESET : PHY_BUS_RESET;
+ if (unlikely(fw_core_param_debug & FW_CORE_PARAM_DEBUG_BUSRESETS))
+ fw_notice(card, "initiating %s bus reset\n",
+ short_reset ? "short" : "long");
+
return card->driver->update_phy_reg(card, reg, 0, bit);
}
void fw_schedule_bus_reset(struct fw_card *card, bool delayed, bool short_reset)
{
+ if (unlikely(fw_core_param_debug & FW_CORE_PARAM_DEBUG_BUSRESETS))
+ fw_notice(card, "scheduling %s bus reset\n",
+ short_reset ? "short" : "long");
+
/* We don't try hard to sort out requests of long vs. short resets. */
card->br_short = short_reset;
@@ -244,6 +252,8 @@ static void br_work(struct work_struct *work)
/* Delay for 2s after last reset per IEEE 1394 clause 8.2.1. */
if (card->reset_jiffies != 0 &&
time_before64(get_jiffies_64(), card->reset_jiffies + 2 * HZ)) {
+ if (unlikely(fw_core_param_debug & FW_CORE_PARAM_DEBUG_BUSRESETS))
+ fw_notice(card, "delaying bus reset\n");
if (!queue_delayed_work(fw_workqueue, &card->br_work, 2 * HZ))
fw_card_put(card);
return;
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 130b95aca6290..c427b7861eaf0 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -1385,5 +1385,12 @@ static void __exit fw_core_cleanup(void)
idr_destroy(&fw_device_idr);
}
+int fw_core_param_debug;
+module_param_named(debug, fw_core_param_debug, int, 0644);
+MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
+ ", bus resets = " __stringify(FW_CORE_PARAM_DEBUG_BUSRESETS)
+ ")");
+
+
module_init(fw_core_init);
module_exit(fw_core_cleanup);
diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index 95c10f3d2282f..ff96e5456b5de 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -238,6 +238,10 @@ static inline bool is_next_generation(int new_generation, int old_generation)
/* OHCI-1394's default upper bound for physical DMA: 4 GB */
#define FW_MAX_PHYSICAL_RANGE (1ULL << 32)
+#define FW_CORE_PARAM_DEBUG_BUSRESETS 1
+
+extern int fw_core_param_debug;
+
void fw_core_handle_request(struct fw_card *card, struct fw_packet *request);
void fw_core_handle_response(struct fw_card *card, struct fw_packet *packet);
int fw_get_response_length(struct fw_request *request);
--
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