firewire: debug interrupt events

This adds debug printks for asynchronous transmission and reception and
for self ID reception.  They can be enabled at module load time, and at
runtime via /sys/module/firewire_ohci/parameters/debug.

Signed-off-by: Jarod Wilson <jwilson@redhat.com>

Also added:  Logging of interrupt event codes and of cancelled AT
packets.

The code now depends on a Kconfig variable.  This makes it easier to
build firewire-ohci without the feature or to make it an option in the
future.  The variable is currently hidden and always on.

This feature inflates firewire-ohci.ko by 7 kB = 27% on x86-64 and by
4 kB = 23% on i686.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

2 files changed, 187 insertions, 0 deletions

diff --git a/drivers/firewire/Kconfig b/drivers/firewire/Kconfig
index 25bdc2dd9ce1..fb4d391810b6 100644
--- a/drivers/firewire/Kconfig
+++ b/drivers/firewire/Kconfig
@@ -54,6 +54,11 @@ config FIREWIRE_OHCI
           directive, use "install modulename /bin/true" for the modules to be
           blacklisted.
 
+config FIREWIRE_OHCI_DEBUG
+        bool
+        depends on FIREWIRE_OHCI
+        default y
+
 config FIREWIRE_SBP2
         tristate "Support for storage devices (SBP-2 protocol driver)"
         depends on FIREWIRE && SCSI
diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index 0c4a07f11a59..b564b1aae52f 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -27,6 +27,7 @@
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/pci.h>
 #include <linux/spinlock.h>
 
@@ -237,6 +238,179 @@ static inline struct fw_ohci *fw_ohci(struct fw_card *card)
 
 static char ohci_driver_name[] = KBUILD_MODNAME;
 
+#ifdef CONFIG_FIREWIRE_OHCI_DEBUG
+
+#define OHCI_PARAM_DEBUG_IRQS           1
+#define OHCI_PARAM_DEBUG_SELFIDS        2
+#define OHCI_PARAM_DEBUG_AT_AR          4
+
+static int param_debug;
+module_param_named(debug, param_debug, int, 0644);
+MODULE_PARM_DESC(debug, "Verbose logging (default = 0"
+        ", IRQs = "             __stringify(OHCI_PARAM_DEBUG_IRQS)
+        ", self-IDs = "         __stringify(OHCI_PARAM_DEBUG_SELFIDS)
+        ", AT/AR events = "     __stringify(OHCI_PARAM_DEBUG_AT_AR)
+        ", or a combination, or all = -1)");
+
+static void log_irqs(u32 evt)
+{
+        if (likely(!(param_debug & OHCI_PARAM_DEBUG_IRQS)))
+                return;
+
+        printk(KERN_DEBUG KBUILD_MODNAME ": IRQ %08x%s%s%s%s%s%s%s%s%s%s%s\n",
+               evt,
+               evt & OHCI1394_selfIDComplete    ? " selfID"             : "",
+               evt & OHCI1394_RQPkt             ? " AR_req"             : "",
+               evt & OHCI1394_RSPkt             ? " AR_resp"            : "",
+               evt & OHCI1394_reqTxComplete     ? " AT_req"             : "",
+               evt & OHCI1394_respTxComplete    ? " AT_resp"            : "",
+               evt & OHCI1394_isochRx           ? " IR"                 : "",
+               evt & OHCI1394_isochTx           ? " IT"                 : "",
+               evt & OHCI1394_postedWriteErr    ? " postedWriteErr"     : "",
+               evt & OHCI1394_cycleTooLong      ? " cycleTooLong"       : "",
+               evt & OHCI1394_cycle64Seconds    ? " cycle64Seconds"     : "",
+               evt & ~(OHCI1394_selfIDComplete | OHCI1394_RQPkt |
+                       OHCI1394_RSPkt | OHCI1394_reqTxComplete |
+                       OHCI1394_respTxComplete | OHCI1394_isochRx |
+                       OHCI1394_isochTx | OHCI1394_postedWriteErr |
+                       OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds)
+                                                ? " ?"                  : "");
+}
+
+static const char *speed[] = {
+        [0] = "S100", [1] = "S200", [2] = "S400",    [3] = "beta",
+};
+static const char *power[] = {
+        [0] = "+0W",  [1] = "+15W", [2] = "+30W",    [3] = "+45W",
+        [4] = "-3W",  [5] = " ?W",  [6] = "-3..-6W", [7] = "-3..-10W",
+};
+static const char port[] = { '.', '-', 'p', 'c', };
+
+static char _p(u32 *s, int shift)
+{
+        return port[*s >> shift & 3];
+}
+
+static void log_selfids(int generation, int self_id_count, u32 *s)
+{
+        if (likely(!(param_debug & OHCI_PARAM_DEBUG_SELFIDS)))
+                return;
+
+        printk(KERN_DEBUG KBUILD_MODNAME ": %d selfIDs, generation %d\n",
+               self_id_count, generation);
+
+        for (; self_id_count--; ++s)
+                if ((*s & 1 << 23) == 0)
+                        printk(KERN_DEBUG "selfID 0: %08x, phy %d [%c%c%c] "
+                               "%s gc=%d %s %s%s%s\n",
+                               *s, *s >> 24 & 63, _p(s, 6), _p(s, 4), _p(s, 2),
+                               speed[*s >> 14 & 3], *s >> 16 & 63,
+                               power[*s >> 8 & 7], *s >> 22 & 1 ? "L" : "",
+                               *s >> 11 & 1 ? "c" : "", *s & 2 ? "i" : "");
+                else
+                        printk(KERN_DEBUG "selfID n: %08x, phy %d "
+                               "[%c%c%c%c%c%c%c%c]\n",
+                               *s, *s >> 24 & 63,
+                               _p(s, 16), _p(s, 14), _p(s, 12), _p(s, 10),
+                               _p(s,  8), _p(s,  6), _p(s,  4), _p(s,  2));
+}
+
+static const char *evts[] = {
+        [0x00] = "evt_no_status",       [0x01] = "-reserved-",
+        [0x02] = "evt_long_packet",     [0x03] = "evt_missing_ack",
+        [0x04] = "evt_underrun",        [0x05] = "evt_overrun",
+        [0x06] = "evt_descriptor_read", [0x07] = "evt_data_read",
+        [0x08] = "evt_data_write",      [0x09] = "evt_bus_reset",
+        [0x0a] = "evt_timeout",         [0x0b] = "evt_tcode_err",
+        [0x0c] = "-reserved-",          [0x0d] = "-reserved-",
+        [0x0e] = "evt_unknown",         [0x0f] = "evt_flushed",
+        [0x10] = "-reserved-",          [0x11] = "ack_complete",
+        [0x12] = "ack_pending ",        [0x13] = "-reserved-",
+        [0x14] = "ack_busy_X",          [0x15] = "ack_busy_A",
+        [0x16] = "ack_busy_B",          [0x17] = "-reserved-",
+        [0x18] = "-reserved-",          [0x19] = "-reserved-",
+        [0x1a] = "-reserved-",          [0x1b] = "ack_tardy",
+        [0x1c] = "-reserved-",          [0x1d] = "ack_data_error",
+        [0x1e] = "ack_type_error",      [0x1f] = "-reserved-",
+        [0x20] = "pending/cancelled",
+};
+static const char *tcodes[] = {
+        [0x0] = "QW req",               [0x1] = "BW req",
+        [0x2] = "W resp",               [0x3] = "-reserved-",
+        [0x4] = "QR req",               [0x5] = "BR req",
+        [0x6] = "QR resp",              [0x7] = "BR resp",
+        [0x8] = "cycle start",          [0x9] = "Lk req",
+        [0xa] = "async stream packet",  [0xb] = "Lk resp",
+        [0xc] = "-reserved-",           [0xd] = "-reserved-",
+        [0xe] = "link internal",        [0xf] = "-reserved-",
+};
+static const char *phys[] = {
+        [0x0] = "phy config packet",    [0x1] = "link-on packet",
+        [0x2] = "self-id packet",       [0x3] = "-reserved-",
+};
+
+static void log_ar_at_event(char dir, int speed, u32 *header, int evt)
+{
+        int tcode = header[0] >> 4 & 0xf;
+        char specific[12];
+
+        if (likely(!(param_debug & OHCI_PARAM_DEBUG_AT_AR)))
+                return;
+
+        if (unlikely(evt >= ARRAY_SIZE(evts)))
+                        evt = 0x1f;
+
+        if (header[0] == ~header[1]) {
+                printk(KERN_DEBUG "A%c %s, %s, %08x\n",
+                       dir, evts[evt], phys[header[0] >> 30 & 0x3],
+                       header[0]);
+                return;
+        }
+
+        switch (tcode) {
+        case 0x0: case 0x6: case 0x8:
+                snprintf(specific, sizeof(specific), " = %08x",
+                         be32_to_cpu((__force __be32)header[3]));
+                break;
+        case 0x1: case 0x5: case 0x7: case 0x9: case 0xb:
+                snprintf(specific, sizeof(specific), " %x,%x",
+                         header[3] >> 16, header[3] & 0xffff);
+                break;
+        default:
+                specific[0] = '\0';
+        }
+
+        switch (tcode) {
+        case 0xe: case 0xa:
+                printk(KERN_DEBUG "A%c %s, %s\n",
+                       dir, evts[evt], tcodes[tcode]);
+                break;
+        case 0x0: case 0x1: case 0x4: case 0x5: case 0x9:
+                printk(KERN_DEBUG "A%c spd %x tl %02x, "
+                       "%04x -> %04x, %s, "
+                       "%s, %04x%08x%s\n",
+                       dir, speed, header[0] >> 10 & 0x3f,
+                       header[1] >> 16, header[0] >> 16, evts[evt],
+                       tcodes[tcode], header[1] & 0xffff, header[2], specific);
+                break;
+        default:
+                printk(KERN_DEBUG "A%c spd %x tl %02x, "
+                       "%04x -> %04x, %s, "
+                       "%s%s\n",
+                       dir, speed, header[0] >> 10 & 0x3f,
+                       header[1] >> 16, header[0] >> 16, evts[evt],
+                       tcodes[tcode], specific);
+        }
+}
+
+#else
+
+#define log_irqs(evt)
+#define log_selfids(generation, self_id_count, sid)
+#define log_ar_at_event(dir, speed, header, evt)
+
+#endif /* CONFIG_FIREWIRE_OHCI_DEBUG */
+
 static inline void reg_write(const struct fw_ohci *ohci, int offset, u32 data)
 {
         writel(data, ohci->registers + offset);
@@ -368,6 +542,8 @@ static __le32 *handle_ar_packet(struct ar_context *ctx, __le32 *buffer)
         p.timestamp  = status & 0xffff;
         p.generation = ohci->request_generation;
 
+        log_ar_at_event('R', p.speed, p.header, status >> 16 & 0x1f);
+
         /*
          * The OHCI bus reset handler synthesizes a phy packet with
          * the new generation number when a bus reset happens (see
@@ -817,6 +993,8 @@ static int handle_at_packet(struct context *context,
         evt = le16_to_cpu(last->transfer_status) & 0x1f;
         packet->timestamp = le16_to_cpu(last->res_count);
 
+        log_ar_at_event('T', packet->speed, packet->header, evt);
+
         switch (evt) {
         case OHCI1394_evt_timeout:
                 /* Async response transmit timed out. */
@@ -1118,6 +1296,8 @@ static void bus_reset_tasklet(unsigned long data)
                 dma_free_coherent(ohci->card.device, CONFIG_ROM_SIZE,
                                   free_rom, free_rom_bus);
 
+        log_selfids(generation, self_id_count, ohci->self_id_buffer);
+
         fw_core_handle_bus_reset(&ohci->card, ohci->node_id, generation,
                                  self_id_count, ohci->self_id_buffer);
 }
@@ -1134,6 +1314,7 @@ static irqreturn_t irq_handler(int irq, void *data)
                 return IRQ_NONE;
 
         reg_write(ohci, OHCI1394_IntEventClear, event);
+        log_irqs(event);
 
         if (event & OHCI1394_selfIDComplete)
                 tasklet_schedule(&ohci->bus_reset_tasklet);
@@ -1436,6 +1617,7 @@ static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
         if (packet->ack != 0)
                 goto out;
 
+        log_ar_at_event('T', packet->speed, packet->header, 0x20);
         driver_data->packet = NULL;
         packet->ack = RCODE_CANCELLED;
         packet->callback(packet, &ohci->card, packet->ack);