8 files changed, 180 insertions, 124 deletions

diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c
index 4eeaed57e219..3c1ac0933d24 100644
--- a/drivers/firewire/core-cdev.c
+++ b/drivers/firewire/core-cdev.c
@@ -25,6 +25,7 @@
 #include <linux/firewire.h>
 #include <linux/firewire-cdev.h>
 #include <linux/idr.h>
+#include <linux/irqflags.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/kref.h>
@@ -32,7 +33,6 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/poll.h>
-#include <linux/preempt.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
@@ -1035,21 +1035,19 @@ static int ioctl_get_cycle_timer(struct client *client, void *buffer)
 {
         struct fw_cdev_get_cycle_timer *request = buffer;
         struct fw_card *card = client->device->card;
-        unsigned long long bus_time;
         struct timeval tv;
-        unsigned long flags;
+        u32 cycle_time;
 
-        preempt_disable();
-        local_irq_save(flags);
+        local_irq_disable();
 
-        bus_time = card->driver->get_bus_time(card);
+        cycle_time = card->driver->get_cycle_time(card);
         do_gettimeofday(&tv);
 
-        local_irq_restore(flags);
-        preempt_enable();
+        local_irq_enable();
 
         request->local_time = tv.tv_sec * 1000000ULL + tv.tv_usec;
-        request->cycle_timer = bus_time & 0xffffffff;
+        request->cycle_timer = cycle_time;
+
         return 0;
 }
 
diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c
index 9d0dfcbe2c1c..eecd52dc8e98 100644
--- a/drivers/firewire/core-device.c
+++ b/drivers/firewire/core-device.c
@@ -43,7 +43,7 @@
 
 #include "core.h"
 
-void fw_csr_iterator_init(struct fw_csr_iterator *ci, u32 * p)
+void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p)
 {
         ci->p = p + 1;
         ci->end = ci->p + (p[0] >> 16);
@@ -59,9 +59,76 @@ int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
 }
 EXPORT_SYMBOL(fw_csr_iterator_next);
 
+static const u32 *search_leaf(const u32 *directory, int search_key)
+{
+        struct fw_csr_iterator ci;
+        int last_key = 0, key, value;
+
+        fw_csr_iterator_init(&ci, directory);
+        while (fw_csr_iterator_next(&ci, &key, &value)) {
+                if (last_key == search_key &&
+                    key == (CSR_DESCRIPTOR | CSR_LEAF))
+                        return ci.p - 1 + value;
+
+                last_key = key;
+        }
+
+        return NULL;
+}
+
+static int textual_leaf_to_string(const u32 *block, char *buf, size_t size)
+{
+        unsigned int quadlets, i;
+        char c;
+
+        if (!size || !buf)
+                return -EINVAL;
+
+        quadlets = min(block[0] >> 16, 256U);
+        if (quadlets < 2)
+                return -ENODATA;
+
+        if (block[1] != 0 || block[2] != 0)
+                /* unknown language/character set */
+                return -ENODATA;
+
+        block += 3;
+        quadlets -= 2;
+        for (i = 0; i < quadlets * 4 && i < size - 1; i++) {
+                c = block[i / 4] >> (24 - 8 * (i % 4));
+                if (c == '\0')
+                        break;
+                buf[i] = c;
+        }
+        buf[i] = '\0';
+
+        return i;
+}
+
+/**
+ * fw_csr_string - reads a string from the configuration ROM
+ * @directory: e.g. root directory or unit directory
+ * @key: the key of the preceding directory entry
+ * @buf: where to put the string
+ * @size: size of @buf, in bytes
+ *
+ * The string is taken from a minimal ASCII text descriptor leaf after
+ * the immediate entry with @key.  The string is zero-terminated.
+ * Returns strlen(buf) or a negative error code.
+ */
+int fw_csr_string(const u32 *directory, int key, char *buf, size_t size)
+{
+        const u32 *leaf = search_leaf(directory, key);
+        if (!leaf)
+                return -ENOENT;
+
+        return textual_leaf_to_string(leaf, buf, size);
+}
+EXPORT_SYMBOL(fw_csr_string);
+
 static bool is_fw_unit(struct device *dev);
 
-static int match_unit_directory(u32 *directory, u32 match_flags,
+static int match_unit_directory(const u32 *directory, u32 match_flags,
                                 const struct ieee1394_device_id *id)
 {
         struct fw_csr_iterator ci;
@@ -195,7 +262,7 @@ static ssize_t show_immediate(struct device *dev,
         struct config_rom_attribute *attr =
                 container_of(dattr, struct config_rom_attribute, attr);
         struct fw_csr_iterator ci;
-        u32 *dir;
+        const u32 *dir;
         int key, value, ret = -ENOENT;
 
         down_read(&fw_device_rwsem);
@@ -226,10 +293,10 @@ static ssize_t show_text_leaf(struct device *dev,
 {
         struct config_rom_attribute *attr =
                 container_of(dattr, struct config_rom_attribute, attr);
-        struct fw_csr_iterator ci;
-        u32 *dir, *block = NULL, *p, *end;
-        int length, key, value, last_key = 0, ret = -ENOENT;
-        char *b;
+        const u32 *dir;
+        size_t bufsize;
+        char dummy_buf[2];
+        int ret;
 
         down_read(&fw_device_rwsem);
 
@@ -238,40 +305,23 @@ static ssize_t show_text_leaf(struct device *dev,
         else
                 dir = fw_device(dev)->config_rom + 5;
 
-        fw_csr_iterator_init(&ci, dir);
-        while (fw_csr_iterator_next(&ci, &key, &value)) {
-                if (attr->key == last_key &&
-                    key == (CSR_DESCRIPTOR | CSR_LEAF))
-                        block = ci.p - 1 + value;
-                last_key = key;
+        if (buf) {
+                bufsize = PAGE_SIZE - 1;
+        } else {
+                buf = dummy_buf;
+                bufsize = 1;
         }
 
-        if (block == NULL)
-                goto out;
-
-        length = min(block[0] >> 16, 256U);
-        if (length < 3)
-                goto out;
+        ret = fw_csr_string(dir, attr->key, buf, bufsize);
 
-        if (block[1] != 0 || block[2] != 0)
-                /* Unknown encoding. */
-                goto out;
-
-        if (buf == NULL) {
-                ret = length * 4;
-                goto out;
+        if (ret >= 0) {
+                /* Strip trailing whitespace and add newline. */
+                while (ret > 0 && isspace(buf[ret - 1]))
+                        ret--;
+                strcpy(buf + ret, "\n");
+                ret++;
         }
 
-        b = buf;
-        end = &block[length + 1];
-        for (p = &block[3]; p < end; p++, b += 4)
-                * (u32 *) b = (__force u32) __cpu_to_be32(*p);
-
-        /* Strip trailing whitespace and add newline. */
-        while (b--, (isspace(*b) || *b == '\0') && b > buf);
-        strcpy(b + 1, "\n");
-        ret = b + 2 - buf;
- out:
         up_read(&fw_device_rwsem);
 
         return ret;
@@ -371,7 +421,7 @@ static ssize_t guid_show(struct device *dev,
         return ret;
 }
 
-static int units_sprintf(char *buf, u32 *directory)
+static int units_sprintf(char *buf, const u32 *directory)
 {
         struct fw_csr_iterator ci;
         int key, value;
@@ -453,7 +503,8 @@ static int read_rom(struct fw_device *device,
  */
 static int read_bus_info_block(struct fw_device *device, int generation)
 {
-        u32 *rom, *stack, *old_rom, *new_rom;
+        const u32 *old_rom, *new_rom;
+        u32 *rom, *stack;
         u32 sp, key;
         int i, end, length, ret = -1;
 
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 495849eb13cc..673b03f8b4ec 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -921,23 +921,15 @@ static void handle_registers(struct fw_card *card, struct fw_request *request,
                 void *payload, size_t length, void *callback_data)
 {
         int reg = offset & ~CSR_REGISTER_BASE;
-        unsigned long long bus_time;
         __be32 *data = payload;
         int rcode = RCODE_COMPLETE;
 
         switch (reg) {
         case CSR_CYCLE_TIME:
-        case CSR_BUS_TIME:
-                if (!TCODE_IS_READ_REQUEST(tcode) || length != 4) {
-                        rcode = RCODE_TYPE_ERROR;
-                        break;
-                }
-
-                bus_time = card->driver->get_bus_time(card);
-                if (reg == CSR_CYCLE_TIME)
-                        *data = cpu_to_be32(bus_time);
+                if (TCODE_IS_READ_REQUEST(tcode) && length == 4)
+                        *data = cpu_to_be32(card->driver->get_cycle_time(card));
                 else
-                        *data = cpu_to_be32(bus_time >> 25);
+                        rcode = RCODE_TYPE_ERROR;
                 break;
 
         case CSR_BROADCAST_CHANNEL:
@@ -968,6 +960,9 @@ static void handle_registers(struct fw_card *card, struct fw_request *request,
         case CSR_BUSY_TIMEOUT:
                 /* FIXME: Implement this. */
 
+        case CSR_BUS_TIME:
+                /* Useless without initialization by the bus manager. */
+
         default:
                 rcode = RCODE_ADDRESS_ERROR;
                 break;
diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index ed3b1a765c00..fb0321300cce 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -70,7 +70,7 @@ struct fw_card_driver {
         int (*enable_phys_dma)(struct fw_card *card,
                                int node_id, int generation);
 
-        u64 (*get_bus_time)(struct fw_card *card);
+        u32 (*get_cycle_time)(struct fw_card *card);
 
         struct fw_iso_context *
         (*allocate_iso_context)(struct fw_card *card,
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 43ebf337b131..0f7c4bb978e7 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -38,7 +38,6 @@
 #include <linux/spinlock.h>
 #include <linux/string.h>
 
-#include <asm/atomic.h>
 #include <asm/byteorder.h>
 #include <asm/page.h>
 #include <asm/system.h>
@@ -187,11 +186,11 @@ struct fw_ohci {
         int node_id;
         int generation;
         int request_generation; /* for timestamping incoming requests */
-        atomic_t bus_seconds;
 
         bool use_dualbuffer;
         bool old_uninorth;
         bool bus_reset_packet_quirk;
+        bool iso_cycle_timer_quirk;
 
         /*
          * Spinlock for accessing fw_ohci data.  Never call out of
@@ -275,7 +274,7 @@ static void log_irqs(u32 evt)
             !(evt & OHCI1394_busReset))
                 return;
 
-        fw_notify("IRQ %08x%s%s%s%s%s%s%s%s%s%s%s%s%s%s\n", evt,
+        fw_notify("IRQ %08x%s%s%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"            : "",
@@ -285,7 +284,6 @@ static void log_irqs(u32 evt)
             evt & OHCI1394_isochTx              ? " IT"                 : "",
             evt & OHCI1394_postedWriteErr       ? " postedWriteErr"     : "",
             evt & OHCI1394_cycleTooLong         ? " cycleTooLong"       : "",
-            evt & OHCI1394_cycle64Seconds       ? " cycle64Seconds"     : "",
             evt & OHCI1394_cycleInconsistent    ? " cycleInconsistent"  : "",
             evt & OHCI1394_regAccessFail        ? " regAccessFail"      : "",
             evt & OHCI1394_busReset             ? " busReset"           : "",
@@ -293,8 +291,7 @@ static void log_irqs(u32 evt)
                     OHCI1394_RSPkt | OHCI1394_reqTxComplete |
                     OHCI1394_respTxComplete | OHCI1394_isochRx |
                     OHCI1394_isochTx | OHCI1394_postedWriteErr |
-                    OHCI1394_cycleTooLong | OHCI1394_cycle64Seconds |
-                    OHCI1394_cycleInconsistent |
+                    OHCI1394_cycleTooLong | OHCI1394_cycleInconsistent |
                     OHCI1394_regAccessFail | OHCI1394_busReset)
                                                 ? " ?"                  : "");
 }
@@ -1384,7 +1381,7 @@ static void bus_reset_tasklet(unsigned long data)
 static irqreturn_t irq_handler(int irq, void *data)
 {
         struct fw_ohci *ohci = data;
-        u32 event, iso_event, cycle_time;
+        u32 event, iso_event;
         int i;
 
         event = reg_read(ohci, OHCI1394_IntEventClear);
@@ -1454,12 +1451,6 @@ static irqreturn_t irq_handler(int irq, void *data)
                         fw_notify("isochronous cycle inconsistent\n");
         }
 
-        if (event & OHCI1394_cycle64Seconds) {
-                cycle_time = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
-                if ((cycle_time & 0x80000000) == 0)
-                        atomic_inc(&ohci->bus_seconds);
-        }
-
         return IRQ_HANDLED;
 }
 
@@ -1553,8 +1544,7 @@ static int ohci_enable(struct fw_card *card,
                   OHCI1394_reqTxComplete | OHCI1394_respTxComplete |
                   OHCI1394_isochRx | OHCI1394_isochTx |
                   OHCI1394_postedWriteErr | OHCI1394_cycleTooLong |
-                  OHCI1394_cycleInconsistent |
-                  OHCI1394_cycle64Seconds | OHCI1394_regAccessFail |
+                  OHCI1394_cycleInconsistent | OHCI1394_regAccessFail |
                   OHCI1394_masterIntEnable);
         if (param_debug & OHCI_PARAM_DEBUG_BUSRESETS)
                 reg_write(ohci, OHCI1394_IntMaskSet, OHCI1394_busReset);
@@ -1794,16 +1784,61 @@ static int ohci_enable_phys_dma(struct fw_card *card,
 #endif /* CONFIG_FIREWIRE_OHCI_REMOTE_DMA */
 }
 
-static u64 ohci_get_bus_time(struct fw_card *card)
+static u32 cycle_timer_ticks(u32 cycle_timer)
 {
-        struct fw_ohci *ohci = fw_ohci(card);
-        u32 cycle_time;
-        u64 bus_time;
+        u32 ticks;
 
-        cycle_time = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
-        bus_time = ((u64)atomic_read(&ohci->bus_seconds) << 32) | cycle_time;
+        ticks = cycle_timer & 0xfff;
+        ticks += 3072 * ((cycle_timer >> 12) & 0x1fff);
+        ticks += (3072 * 8000) * (cycle_timer >> 25);
 
-        return bus_time;
+        return ticks;
+}
+
+/*
+ * Some controllers exhibit one or more of the following bugs when updating the
+ * iso cycle timer register:
+ *  - When the lowest six bits are wrapping around to zero, a read that happens
+ *    at the same time will return garbage in the lowest ten bits.
+ *  - When the cycleOffset field wraps around to zero, the cycleCount field is
+ *    not incremented for about 60 ns.
+ *  - Occasionally, the entire register reads zero.
+ *
+ * To catch these, we read the register three times and ensure that the
+ * difference between each two consecutive reads is approximately the same, i.e.
+ * less than twice the other.  Furthermore, any negative difference indicates an
+ * error.  (A PCI read should take at least 20 ticks of the 24.576 MHz timer to
+ * execute, so we have enough precision to compute the ratio of the differences.)
+ */
+static u32 ohci_get_cycle_time(struct fw_card *card)
+{
+        struct fw_ohci *ohci = fw_ohci(card);
+        u32 c0, c1, c2;
+        u32 t0, t1, t2;
+        s32 diff01, diff12;
+        int i;
+
+        c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
+
+        if (ohci->iso_cycle_timer_quirk) {
+                i = 0;
+                c1 = c2;
+                c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
+                do {
+                        c0 = c1;
+                        c1 = c2;
+                        c2 = reg_read(ohci, OHCI1394_IsochronousCycleTimer);
+                        t0 = cycle_timer_ticks(c0);
+                        t1 = cycle_timer_ticks(c1);
+                        t2 = cycle_timer_ticks(c2);
+                        diff01 = t1 - t0;
+                        diff12 = t2 - t1;
+                } while ((diff01 <= 0 || diff12 <= 0 ||
+                          diff01 / diff12 >= 2 || diff12 / diff01 >= 2)
+                         && i++ < 20);
+        }
+
+        return c2;
 }
 
 static void copy_iso_headers(struct iso_context *ctx, void *p)
@@ -2383,7 +2418,7 @@ static const struct fw_card_driver ohci_driver = {
         .send_response          = ohci_send_response,
         .cancel_packet          = ohci_cancel_packet,
         .enable_phys_dma        = ohci_enable_phys_dma,
-        .get_bus_time           = ohci_get_bus_time,
+        .get_cycle_time         = ohci_get_cycle_time,
 
         .allocate_iso_context   = ohci_allocate_iso_context,
         .free_iso_context       = ohci_free_iso_context,
@@ -2503,6 +2538,10 @@ static int __devinit pci_probe(struct pci_dev *dev,
 #endif
         ohci->bus_reset_packet_quirk = dev->vendor == PCI_VENDOR_ID_TI;
 
+        ohci->iso_cycle_timer_quirk = dev->vendor == PCI_VENDOR_ID_AL   ||
+                                      dev->vendor == PCI_VENDOR_ID_NEC  ||
+                                      dev->vendor == PCI_VENDOR_ID_VIA;
+
         ar_context_init(&ohci->ar_request_ctx, ohci,
                         OHCI1394_AsReqRcvContextControlSet);
 
@@ -2662,7 +2701,7 @@ static int pci_resume(struct pci_dev *dev)
 }
 #endif
 
-static struct pci_device_id pci_table[] = {
+static const struct pci_device_id pci_table[] = {
         { PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_FIREWIRE_OHCI, ~0) },
         { }
 };
diff --git a/drivers/firewire/sbp2.c b/drivers/firewire/sbp2.c
index d485cdd8cbac..7e33b0b1704c 100644
--- a/drivers/firewire/sbp2.c
+++ b/drivers/firewire/sbp2.c
@@ -1014,7 +1014,8 @@ static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
         return 0;
 }
 
-static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
+static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt,
+                                      const u32 *directory)
 {
         struct fw_csr_iterator ci;
         int key, value;
@@ -1027,7 +1028,7 @@ static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt, u32 *directory)
         return 0;
 }
 
-static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
+static int sbp2_scan_unit_dir(struct sbp2_target *tgt, const u32 *directory,
                               u32 *model, u32 *firmware_revision)
 {
         struct fw_csr_iterator ci;
diff --git a/drivers/media/dvb/firewire/firedtv-fw.c b/drivers/media/dvb/firewire/firedtv-fw.c
index 6223bf01efe9..4253b7ab0097 100644
--- a/drivers/media/dvb/firewire/firedtv-fw.c
+++ b/drivers/media/dvb/firewire/firedtv-fw.c
@@ -239,47 +239,18 @@ static const struct fw_address_region fcp_region = {
 };
 
 /* Adjust the template string if models with longer names appear. */
-#define MAX_MODEL_NAME_LEN ((int)DIV_ROUND_UP(sizeof("FireDTV ????"), 4))
-
-static size_t model_name(u32 *directory, __be32 *buffer)
-{
-        struct fw_csr_iterator ci;
-        int i, length, key, value, last_key = 0;
-        u32 *block = NULL;
-
-        fw_csr_iterator_init(&ci, directory);
-        while (fw_csr_iterator_next(&ci, &key, &value)) {
-                if (last_key == CSR_MODEL &&
-                    key == (CSR_DESCRIPTOR | CSR_LEAF))
-                        block = ci.p - 1 + value;
-                last_key = key;
-        }
-
-        if (block == NULL)
-                return 0;
-
-        length = min((int)(block[0] >> 16) - 2, MAX_MODEL_NAME_LEN);
-        if (length <= 0)
-                return 0;
-
-        /* fast-forward to text string */
-        block += 3;
-
-        for (i = 0; i < length; i++)
-                buffer[i] = cpu_to_be32(block[i]);
-
-        return length * 4;
-}
+#define MAX_MODEL_NAME_LEN sizeof("FireDTV ????")
 
 static int node_probe(struct device *dev)
 {
         struct firedtv *fdtv;
-        __be32 name[MAX_MODEL_NAME_LEN];
+        char name[MAX_MODEL_NAME_LEN];
         int name_len, err;
 
-        name_len = model_name(fw_unit(dev)->directory, name);
+        name_len = fw_csr_string(fw_unit(dev)->directory, CSR_MODEL,
+                                 name, sizeof(name));
 
-        fdtv = fdtv_alloc(dev, &backend, (char *)name, name_len);
+        fdtv = fdtv_alloc(dev, &backend, name, name_len >= 0 ? name_len : 0);
         if (!fdtv)
                 return -ENOMEM;
 
diff --git a/include/linux/firewire.h b/include/linux/firewire.h
index a0e67150a729..4bd94bf5e739 100644
--- a/include/linux/firewire.h
+++ b/include/linux/firewire.h
@@ -65,12 +65,13 @@
 #define CSR_DIRECTORY_ID        0x20
 
 struct fw_csr_iterator {
-        u32 *p;
-        u32 *end;
+        const u32 *p;
+        const u32 *end;
 };
 
-void fw_csr_iterator_init(struct fw_csr_iterator *ci, u32 *p);
+void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p);
 int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value);
+int fw_csr_string(const u32 *directory, int key, char *buf, size_t size);
 
 extern struct bus_type fw_bus_type;
 
@@ -162,7 +163,7 @@ struct fw_device {
         struct mutex client_list_mutex;
         struct list_head client_list;
 
-        u32 *config_rom;
+        const u32 *config_rom;
         size_t config_rom_length;
         int config_rom_retries;
         unsigned is_local:1;
@@ -204,7 +205,7 @@ int fw_device_enable_phys_dma(struct fw_device *device);
  */
 struct fw_unit {
         struct device device;
-        u32 *directory;
+        const u32 *directory;
         struct fw_attribute_group attribute_group;
 };