From a7611e84bd06c70c8b0cd88cd1e474c3c42fee3e Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Mon, 12 Mar 2012 21:46:55 +0100 Subject: firewire: cdev: fix IR multichannel event documentation State more precisely when fw_cdev_event_iso_interrupt_mc is sent. While the comment tried to reflect an amibuity in the OHCI specification, there is only one method that is useful in practice, and this also matches all the hardware implementations I've tested. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter --- include/linux/firewire-cdev.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'include/linux/firewire-cdev.h') diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h index 357dbfc2829..cc1b570a2eb 100644 --- a/include/linux/firewire-cdev.h +++ b/include/linux/firewire-cdev.h @@ -267,9 +267,8 @@ struct fw_cdev_event_iso_interrupt { * * This event is sent in multichannel contexts (context type * %FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL) for &fw_cdev_iso_packet buffer - * chunks that have the %FW_CDEV_ISO_INTERRUPT bit set. Whether this happens - * when a packet is completed and/or when a buffer chunk is completed depends - * on the hardware implementation. + * chunks that have been completely filled and that have the + * %FW_CDEV_ISO_INTERRUPT bit set. * * The buffer is continuously filled with the following data, per packet: * - the 1394 iso packet header as described at &fw_cdev_event_iso_interrupt, -- cgit v1.2.3-70-g09d2 From 18d627113b830cda80792e96b28341bcd41cf40c Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Sun, 18 Mar 2012 19:05:29 +0100 Subject: firewire: prevent dropping of completed iso packet header data The buffer for the header data of completed iso packets has a fixed size, so it is possible to configure a stream with a big interval between interrupt packets or with big headers so that this buffer would overflow. Previously, ohci.c would drop any data that would not fit, but this could make unsuspecting applications believe that fewer than the actual number of packets have completed. Instead of dropping data, add calls to flush_iso_completion() so that there are as many events as needed to report all of the data. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter --- drivers/firewire/core-cdev.c | 2 +- drivers/firewire/ohci.c | 18 +++++++++--------- include/linux/firewire-cdev.h | 9 +++++++-- 3 files changed, 17 insertions(+), 12 deletions(-) (limited to 'include/linux/firewire-cdev.h') diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c index f5f5a9706fc..4cb27dc542c 100644 --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -51,7 +51,7 @@ /* * ABI version history is documented in linux/firewire-cdev.h. */ -#define FW_CDEV_KERNEL_VERSION 4 +#define FW_CDEV_KERNEL_VERSION 5 #define FW_CDEV_VERSION_EVENT_REQUEST2 4 #define FW_CDEV_VERSION_ALLOCATE_REGION_END 4 diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 07d3c8d58b3..632562667a0 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -2689,7 +2689,7 @@ static void copy_iso_headers(struct iso_context *ctx, const u32 *dma_hdr) u32 *ctx_hdr; if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) - return; + flush_iso_completions(ctx); ctx_hdr = ctx->header + ctx->header_length; ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]); @@ -2826,16 +2826,16 @@ static int handle_it_packet(struct context *context, sync_it_packet_for_cpu(context, d); - if (ctx->header_length + 4 < PAGE_SIZE) { - ctx_hdr = ctx->header + ctx->header_length; - /* Present this value as big-endian to match the receive code */ - *ctx_hdr = cpu_to_be32( - ((u32)le16_to_cpu(pd->transfer_status) << 16) | - le16_to_cpu(pd->res_count)); - ctx->header_length += 4; - } + if (ctx->header_length + 4 > PAGE_SIZE) + flush_iso_completions(ctx); + ctx_hdr = ctx->header + ctx->header_length; ctx->last_timestamp = le16_to_cpu(last->res_count); + /* Present this value as big-endian to match the receive code */ + *ctx_hdr = cpu_to_be32((le16_to_cpu(pd->transfer_status) << 16) | + le16_to_cpu(pd->res_count)); + ctx->header_length += 4; + if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) flush_iso_completions(ctx); diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h index cc1b570a2eb..b9bd349c693 100644 --- a/include/linux/firewire-cdev.h +++ b/include/linux/firewire-cdev.h @@ -207,12 +207,15 @@ struct fw_cdev_event_request2 { * @closure: See &fw_cdev_event_common; * set by %FW_CDEV_CREATE_ISO_CONTEXT ioctl * @type: See &fw_cdev_event_common; always %FW_CDEV_EVENT_ISO_INTERRUPT - * @cycle: Cycle counter of the interrupt packet + * @cycle: Cycle counter of the last completed packet * @header_length: Total length of following headers, in bytes * @header: Stripped headers, if any * * This event is sent when the controller has completed an &fw_cdev_iso_packet - * with the %FW_CDEV_ISO_INTERRUPT bit set. + * with the %FW_CDEV_ISO_INTERRUPT bit set, or when there have been so many + * completed packets without the interrupt bit set that the kernel's internal + * buffer for @header is about to overflow. (In the latter case, kernels with + * ABI version < 5 drop header data up to the next interrupt packet.) * * Isochronous transmit events (context type %FW_CDEV_ISO_CONTEXT_TRANSMIT): * @@ -440,6 +443,8 @@ union fw_cdev_event { * - added %FW_CDEV_EVENT_ISO_INTERRUPT_MULTICHANNEL, * %FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL, and * %FW_CDEV_IOC_SET_ISO_CHANNELS + * 5 (3.4) - send %FW_CDEV_EVENT_ISO_INTERRUPT events when needed to + * avoid dropping data */ /** -- cgit v1.2.3-70-g09d2 From d1bbd20972936b9b178fda3eb1ec417cb27fdc01 Mon Sep 17 00:00:00 2001 From: Clemens Ladisch Date: Sun, 18 Mar 2012 19:06:39 +0100 Subject: firewire: allow explicit flushing of iso packet completions Extend the kernel and userspace APIs to allow reporting all currently completed isochronous packets, even if the next interrupt packet has not yet been reached. This is required to determine the status of the packets at the end of a paused or stopped stream, and useful for more precise synchronization of audio streams. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter --- drivers/firewire/core-card.c | 6 ++++ drivers/firewire/core-cdev.c | 12 +++++++ drivers/firewire/core-iso.c | 6 ++++ drivers/firewire/core.h | 2 ++ drivers/firewire/ohci.c | 78 ++++++++++++++++++++++++++++++++++++++----- include/linux/firewire-cdev.h | 35 ++++++++++++++++--- include/linux/firewire.h | 1 + 7 files changed, 127 insertions(+), 13 deletions(-) (limited to 'include/linux/firewire-cdev.h') diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c index b19db0f6a25..cc595eba7ba 100644 --- a/drivers/firewire/core-card.c +++ b/drivers/firewire/core-card.c @@ -650,6 +650,11 @@ static void dummy_flush_queue_iso(struct fw_iso_context *ctx) { } +static int dummy_flush_iso_completions(struct fw_iso_context *ctx) +{ + return -ENODEV; +} + static const struct fw_card_driver dummy_driver_template = { .read_phy_reg = dummy_read_phy_reg, .update_phy_reg = dummy_update_phy_reg, @@ -662,6 +667,7 @@ static const struct fw_card_driver dummy_driver_template = { .set_iso_channels = dummy_set_iso_channels, .queue_iso = dummy_queue_iso, .flush_queue_iso = dummy_flush_queue_iso, + .flush_iso_completions = dummy_flush_iso_completions, }; void fw_card_release(struct kref *kref) diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c index 4cb27dc542c..22c6df5f136 100644 --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -438,6 +438,7 @@ union ioctl_arg { struct fw_cdev_send_phy_packet send_phy_packet; struct fw_cdev_receive_phy_packets receive_phy_packets; struct fw_cdev_set_iso_channels set_iso_channels; + struct fw_cdev_flush_iso flush_iso; }; static int ioctl_get_info(struct client *client, union ioctl_arg *arg) @@ -1168,6 +1169,16 @@ static int ioctl_stop_iso(struct client *client, union ioctl_arg *arg) return fw_iso_context_stop(client->iso_context); } +static int ioctl_flush_iso(struct client *client, union ioctl_arg *arg) +{ + struct fw_cdev_flush_iso *a = &arg->flush_iso; + + if (client->iso_context == NULL || a->handle != 0) + return -EINVAL; + + return fw_iso_context_flush_completions(client->iso_context); +} + static int ioctl_get_cycle_timer2(struct client *client, union ioctl_arg *arg) { struct fw_cdev_get_cycle_timer2 *a = &arg->get_cycle_timer2; @@ -1589,6 +1600,7 @@ static int (* const ioctl_handlers[])(struct client *, union ioctl_arg *) = { [0x15] = ioctl_send_phy_packet, [0x16] = ioctl_receive_phy_packets, [0x17] = ioctl_set_iso_channels, + [0x18] = ioctl_flush_iso, }; static int dispatch_ioctl(struct client *client, diff --git a/drivers/firewire/core-iso.c b/drivers/firewire/core-iso.c index 57c3973093a..2f432a20ce7 100644 --- a/drivers/firewire/core-iso.c +++ b/drivers/firewire/core-iso.c @@ -191,6 +191,12 @@ void fw_iso_context_queue_flush(struct fw_iso_context *ctx) } EXPORT_SYMBOL(fw_iso_context_queue_flush); +int fw_iso_context_flush_completions(struct fw_iso_context *ctx) +{ + return ctx->card->driver->flush_iso_completions(ctx); +} +EXPORT_SYMBOL(fw_iso_context_flush_completions); + int fw_iso_context_stop(struct fw_iso_context *ctx) { return ctx->card->driver->stop_iso(ctx); diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h index 62f57a4331e..9047f5547d9 100644 --- a/drivers/firewire/core.h +++ b/drivers/firewire/core.h @@ -106,6 +106,8 @@ struct fw_card_driver { void (*flush_queue_iso)(struct fw_iso_context *ctx); + int (*flush_iso_completions)(struct fw_iso_context *ctx); + int (*stop_iso)(struct fw_iso_context *ctx); }; diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 632562667a0..59e7894ae3b 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -172,6 +172,9 @@ struct iso_context { struct context context; void *header; size_t header_length; + unsigned long flushing_completions; + u32 mc_buffer_bus; + u16 mc_completed; u16 last_timestamp; u8 sync; u8 tags; @@ -2749,28 +2752,51 @@ static int handle_ir_buffer_fill(struct context *context, { struct iso_context *ctx = container_of(context, struct iso_context, context); + unsigned int req_count, res_count, completed; u32 buffer_dma; - if (last->res_count != 0) + req_count = le16_to_cpu(last->req_count); + res_count = le16_to_cpu(ACCESS_ONCE(last->res_count)); + completed = req_count - res_count; + buffer_dma = le32_to_cpu(last->data_address); + + if (completed > 0) { + ctx->mc_buffer_bus = buffer_dma; + ctx->mc_completed = completed; + } + + if (res_count != 0) /* Descriptor(s) not done yet, stop iteration */ return 0; - buffer_dma = le32_to_cpu(last->data_address); dma_sync_single_range_for_cpu(context->ohci->card.device, buffer_dma & PAGE_MASK, buffer_dma & ~PAGE_MASK, - le16_to_cpu(last->req_count), - DMA_FROM_DEVICE); + completed, DMA_FROM_DEVICE); - if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) + if (last->control & cpu_to_le16(DESCRIPTOR_IRQ_ALWAYS)) { ctx->base.callback.mc(&ctx->base, - le32_to_cpu(last->data_address) + - le16_to_cpu(last->req_count), + buffer_dma + completed, ctx->base.callback_data); + ctx->mc_completed = 0; + } return 1; } +static void flush_ir_buffer_fill(struct iso_context *ctx) +{ + dma_sync_single_range_for_cpu(ctx->context.ohci->card.device, + ctx->mc_buffer_bus & PAGE_MASK, + ctx->mc_buffer_bus & ~PAGE_MASK, + ctx->mc_completed, DMA_FROM_DEVICE); + + ctx->base.callback.mc(&ctx->base, + ctx->mc_buffer_bus + ctx->mc_completed, + ctx->base.callback_data); + ctx->mc_completed = 0; +} + static inline void sync_it_packet_for_cpu(struct context *context, struct descriptor *pd) { @@ -2925,8 +2951,10 @@ static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card, if (ret < 0) goto out_with_header; - if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) + if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) { set_multichannel_mask(ohci, 0); + ctx->mc_completed = 0; + } return &ctx->base; @@ -3388,6 +3416,39 @@ static void ohci_flush_queue_iso(struct fw_iso_context *base) reg_write(ctx->ohci, CONTROL_SET(ctx->regs), CONTEXT_WAKE); } +static int ohci_flush_iso_completions(struct fw_iso_context *base) +{ + struct iso_context *ctx = container_of(base, struct iso_context, base); + int ret = 0; + + tasklet_disable(&ctx->context.tasklet); + + if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) { + context_tasklet((unsigned long)&ctx->context); + + switch (base->type) { + case FW_ISO_CONTEXT_TRANSMIT: + case FW_ISO_CONTEXT_RECEIVE: + if (ctx->header_length != 0) + flush_iso_completions(ctx); + break; + case FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL: + if (ctx->mc_completed != 0) + flush_ir_buffer_fill(ctx); + break; + default: + ret = -ENOSYS; + } + + clear_bit_unlock(0, &ctx->flushing_completions); + smp_mb__after_clear_bit(); + } + + tasklet_enable(&ctx->context.tasklet); + + return ret; +} + static const struct fw_card_driver ohci_driver = { .enable = ohci_enable, .read_phy_reg = ohci_read_phy_reg, @@ -3405,6 +3466,7 @@ static const struct fw_card_driver ohci_driver = { .set_iso_channels = ohci_set_iso_channels, .queue_iso = ohci_queue_iso, .flush_queue_iso = ohci_flush_queue_iso, + .flush_iso_completions = ohci_flush_iso_completions, .start_iso = ohci_start_iso, .stop_iso = ohci_stop_iso, }; diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h index b9bd349c693..d5003695349 100644 --- a/include/linux/firewire-cdev.h +++ b/include/linux/firewire-cdev.h @@ -212,10 +212,11 @@ struct fw_cdev_event_request2 { * @header: Stripped headers, if any * * This event is sent when the controller has completed an &fw_cdev_iso_packet - * with the %FW_CDEV_ISO_INTERRUPT bit set, or when there have been so many - * completed packets without the interrupt bit set that the kernel's internal - * buffer for @header is about to overflow. (In the latter case, kernels with - * ABI version < 5 drop header data up to the next interrupt packet.) + * with the %FW_CDEV_ISO_INTERRUPT bit set, when explicitly requested with + * %FW_CDEV_IOC_FLUSH_ISO, or when there have been so many completed packets + * without the interrupt bit set that the kernel's internal buffer for @header + * is about to overflow. (In the last case, kernels with ABI version < 5 drop + * header data up to the next interrupt packet.) * * Isochronous transmit events (context type %FW_CDEV_ISO_CONTEXT_TRANSMIT): * @@ -271,7 +272,8 @@ struct fw_cdev_event_iso_interrupt { * This event is sent in multichannel contexts (context type * %FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL) for &fw_cdev_iso_packet buffer * chunks that have been completely filled and that have the - * %FW_CDEV_ISO_INTERRUPT bit set. + * %FW_CDEV_ISO_INTERRUPT bit set, or when explicitly requested with + * %FW_CDEV_IOC_FLUSH_ISO. * * The buffer is continuously filled with the following data, per packet: * - the 1394 iso packet header as described at &fw_cdev_event_iso_interrupt, @@ -421,6 +423,9 @@ union fw_cdev_event { #define FW_CDEV_IOC_RECEIVE_PHY_PACKETS _IOW('#', 0x16, struct fw_cdev_receive_phy_packets) #define FW_CDEV_IOC_SET_ISO_CHANNELS _IOW('#', 0x17, struct fw_cdev_set_iso_channels) +/* available since kernel version 3.4 */ +#define FW_CDEV_IOC_FLUSH_ISO _IOW('#', 0x18, struct fw_cdev_flush_iso) + /* * ABI version history * 1 (2.6.22) - initial version @@ -445,6 +450,7 @@ union fw_cdev_event { * %FW_CDEV_IOC_SET_ISO_CHANNELS * 5 (3.4) - send %FW_CDEV_EVENT_ISO_INTERRUPT events when needed to * avoid dropping data + * - added %FW_CDEV_IOC_FLUSH_ISO */ /** @@ -854,6 +860,25 @@ struct fw_cdev_stop_iso { __u32 handle; }; +/** + * struct fw_cdev_flush_iso - flush completed iso packets + * @handle: handle of isochronous context to flush + * + * For %FW_CDEV_ISO_CONTEXT_TRANSMIT or %FW_CDEV_ISO_CONTEXT_RECEIVE contexts, + * report any completed packets. + * + * For %FW_CDEV_ISO_CONTEXT_RECEIVE_MULTICHANNEL contexts, report the current + * offset in the receive buffer, if it has changed; this is typically in the + * middle of some buffer chunk. + * + * Any %FW_CDEV_EVENT_ISO_INTERRUPT or %FW_CDEV_EVENT_ISO_INTERRUPT_MULTICHANNEL + * events generated by this ioctl are sent synchronously, i.e., are available + * for reading from the file descriptor when this ioctl returns. + */ +struct fw_cdev_flush_iso { + __u32 handle; +}; + /** * struct fw_cdev_get_cycle_timer - read cycle timer register * @local_time: system time, in microseconds since the Epoch diff --git a/include/linux/firewire.h b/include/linux/firewire.h index ab5b7a18dec..cdc9b719e9c 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -426,6 +426,7 @@ int fw_iso_context_queue(struct fw_iso_context *ctx, struct fw_iso_buffer *buffer, unsigned long payload); void fw_iso_context_queue_flush(struct fw_iso_context *ctx); +int fw_iso_context_flush_completions(struct fw_iso_context *ctx); int fw_iso_context_start(struct fw_iso_context *ctx, int cycle, int sync, int tags); int fw_iso_context_stop(struct fw_iso_context *ctx); -- cgit v1.2.3-70-g09d2