aboutsummaryrefslogtreecommitdiff
path: root/drivers/firewire/ohci.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/firewire/ohci.c')
-rw-r--r--drivers/firewire/ohci.c87
1 files changed, 63 insertions, 24 deletions
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 43ebf337b13..0f7c4bb978e 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) },
{ }
};