diff --git a/drivers/ieee1394/iso.h b/drivers/ieee1394/iso.h index b94e55e6eaa5..b5de5f21ef78 100644 --- a/drivers/ieee1394/iso.h +++ b/drivers/ieee1394/iso.h @@ -123,6 +123,8 @@ struct hpsb_iso { /* how many times the buffer has overflowed or underflowed */ atomic_t overflows; + /* how many cycles were skipped for a given context */ + atomic_t skips; /* Current number of bytes lost in discarded packets */ int bytes_discarded; diff --git a/drivers/ieee1394/ohci1394.c b/drivers/ieee1394/ohci1394.c index 0690469fcecf..e509e13cb7a7 100644 --- a/drivers/ieee1394/ohci1394.c +++ b/drivers/ieee1394/ohci1394.c @@ -1723,6 +1723,8 @@ struct ohci_iso_xmit { struct dma_prog_region prog; struct ohci1394_iso_tasklet task; int task_active; + int last_cycle; + atomic_t skips; u32 ContextControlSet; u32 ContextControlClear; @@ -1759,6 +1761,8 @@ static int ohci_iso_xmit_init(struct hpsb_iso *iso) iso->hostdata = xmit; xmit->ohci = iso->host->hostdata; xmit->task_active = 0; + xmit->last_cycle = -1; + atomic_set(&iso->skips, 0); dma_prog_region_init(&xmit->prog); @@ -1856,6 +1860,26 @@ static void ohci_iso_xmit_task(unsigned long data) /* parse cycle */ cycle = le32_to_cpu(cmd->output_last.status) & 0x1FFF; + if (xmit->last_cycle > -1) { + int cycle_diff = cycle - xmit->last_cycle; + int skip; + + /* unwrap */ + if (cycle_diff < 0) { + cycle_diff += 8000; + if (cycle_diff < 0) + PRINT(KERN_ERR, "bogus cycle diff %d\n", + cycle_diff); + } + + skip = cycle_diff - 1; + if (skip > 0) { + DBGMSG("skipped %d cycles without packet loss", skip); + atomic_add(skip, &iso->skips); + } + } + xmit->last_cycle = cycle; + /* tell the subsystem the packet has gone out */ hpsb_iso_packet_sent(iso, cycle, event != 0x11); @@ -1943,6 +1967,16 @@ static int ohci_iso_xmit_queue(struct hpsb_iso *iso, struct hpsb_iso_packet_info prev->output_last.branchAddress = cpu_to_le32( dma_prog_region_offset_to_bus(&xmit->prog, sizeof(struct iso_xmit_cmd) * next_i) | 3); + /* + * Link the skip address to this descriptor itself. This causes a + * context to skip a cycle whenever lost cycles or FIFO overruns occur, + * without dropping the data at that point the application should then + * decide whether this is an error condition or not. Some protocols + * can deal with this by dropping some rate-matching padding packets. + */ + next->output_more_immediate.branchAddress = + prev->output_last.branchAddress; + /* disable interrupt, unless required by the IRQ interval */ if (prev_i % iso->irq_interval) { prev->output_last.control &= cpu_to_le32(~(3 << 20)); /* no interrupt */ diff --git a/drivers/ieee1394/raw1394.c b/drivers/ieee1394/raw1394.c index 04e96ba56e09..567dafc2369d 100644 --- a/drivers/ieee1394/raw1394.c +++ b/drivers/ieee1394/raw1394.c @@ -2356,13 +2356,16 @@ static void rawiso_activity_cb(struct hpsb_iso *iso) static void raw1394_iso_fill_status(struct hpsb_iso *iso, struct raw1394_iso_status *stat) { + int overflows = atomic_read(&iso->overflows); + int skips = atomic_read(&iso->skips); + stat->config.data_buf_size = iso->buf_size; stat->config.buf_packets = iso->buf_packets; stat->config.channel = iso->channel; stat->config.speed = iso->speed; stat->config.irq_interval = iso->irq_interval; stat->n_packets = hpsb_iso_n_ready(iso); - stat->overflows = atomic_read(&iso->overflows); + stat->overflows = ((skips & 0xFFFF) << 16) | ((overflows & 0xFFFF)); stat->xmit_cycle = iso->xmit_cycle; } @@ -2437,6 +2440,8 @@ static int raw1394_iso_get_status(struct file_info *fi, void __user * uaddr) /* reset overflow counter */ atomic_set(&iso->overflows, 0); + /* reset skip counter */ + atomic_set(&iso->skips, 0); return 0; }