1394 OHCI hardware triggers PCI interrupts to notify any events to
software. Current driver for the hardware is programmed by the typical
way to utilize top- and bottom- halves, thus it has a timing gap to handle
the notification in softIRQ (tasklet).
This commit adds a tracepoint event for the hardIRQ event. The comparison
of the tracepoint event to tracepoints events in firewire subsystem is
helpful to diagnose the timing gap.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
drivers/firewire/ohci.c | 1 +
include/trace/events/firewire_ohci.h | 33 +++++++++++++++++++++++++++-
2 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 07adb4ddd444..df16a8f4ee7f 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -2185,6 +2185,7 @@ static irqreturn_t irq_handler(int irq, void *data)
*/
reg_write(ohci, OHCI1394_IntEventClear,
event & ~(OHCI1394_busReset | OHCI1394_postedWriteErr));
+ trace_irqs(ohci->card.index, event);
log_irqs(ohci, event);
// The flag is masked again at bus_reset_work() scheduled by selfID event.
if (event & OHCI1394_busReset)
diff --git a/include/trace/events/firewire_ohci.h b/include/trace/events/firewire_ohci.h
index 67fa3c1c8f6d..483aeeb033af 100644
--- a/include/trace/events/firewire_ohci.h
+++ b/include/trace/events/firewire_ohci.h
@@ -9,7 +9,38 @@
#include <linux/tracepoint.h>
-// Placeholder for future use.
+TRACE_EVENT(irqs,
+ TP_PROTO(unsigned int card_index, u32 events),
+ TP_ARGS(card_index, events),
+ TP_STRUCT__entry(
+ __field(u8, card_index)
+ __field(u32, events)
+ ),
+ TP_fast_assign(
+ __entry->card_index = card_index;
+ __entry->events = events;
+ ),
+ TP_printk(
+ "card_index=%u events=%s",
+ __entry->card_index,
+ __print_flags(__entry->events, "|",
+ { OHCI1394_selfIDComplete, "selfIDComplete" },
+ { OHCI1394_RQPkt, "RQPkt" },
+ { OHCI1394_RSPkt, "RSPkt" },
+ { OHCI1394_reqTxComplete, "reqTxComplete" },
+ { OHCI1394_respTxComplete, "respTxComplete" },
+ { OHCI1394_isochRx, "isochRx" },
+ { OHCI1394_isochTx, "isochTx" },
+ { OHCI1394_postedWriteErr, "postedWriteErr" },
+ { OHCI1394_cycleTooLong, "cycleTooLong" },
+ { OHCI1394_cycle64Seconds, "cycle64Seconds" },
+ { OHCI1394_cycleInconsistent, "cycleInconsistent" },
+ { OHCI1394_regAccessFail, "regAccessFail" },
+ { OHCI1394_unrecoverableError, "unrecoverableError" },
+ { OHCI1394_busReset, "busReset" }
+ )
+ )
+);
#endif // _FIREWIRE_OHCI_TRACE_EVENT_H
--
2.43.0