Date: Wed, 31 Jul 2013 20:10:33 +0200 From: Clemens Ladisch Subject: firewire: fix libdc1394/FlyCap2 iso event regression Commit 0699a73af3811b66b1ab5650575acee5eea841ab upstream, 3.4 backport. Commit 18d627113b83 (firewire: prevent dropping of completed iso packet header data) was intended to be an obvious bug fix, but libdc1394 and FlyCap2 depend on the old behaviour by ignoring all returned information and thus not noticing that not all packets have been received yet. The result was that the video frame buffers would be saved before they contained the correct data. Reintroduce the old behaviour for old clients. Tested-by: Stepan Salenikovich Tested-by: Josep Bosch Cc: # 3.4+ Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter --- drivers/firewire/core-cdev.c | 3 +++ drivers/firewire/ohci.c | 10 ++++++++-- include/linux/firewire-cdev.h | 4 ++-- include/linux/firewire.h | 1 + 4 files changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/firewire/core-cdev.c b/drivers/firewire/core-cdev.c index 2e6b245..1135857 100644 --- a/drivers/firewire/core-cdev.c +++ b/drivers/firewire/core-cdev.c @@ -53,6 +53,7 @@ #define FW_CDEV_KERNEL_VERSION 5 #define FW_CDEV_VERSION_EVENT_REQUEST2 4 #define FW_CDEV_VERSION_ALLOCATE_REGION_END 4 +#define FW_CDEV_VERSION_AUTO_FLUSH_ISO_OVERFLOW 5 struct client { u32 version; @@ -998,6 +999,8 @@ static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg) a->channel, a->speed, a->header_size, cb, client); if (IS_ERR(context)) return PTR_ERR(context); + if (client->version < FW_CDEV_VERSION_AUTO_FLUSH_ISO_OVERFLOW) + context->drop_overflow_headers = true; /* We only support one context at this time. */ spin_lock_irq(&client->lock); diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 2b54600..c1de4c3 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -2694,8 +2694,11 @@ 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) + if (ctx->header_length + ctx->base.header_size > PAGE_SIZE) { + if (ctx->base.drop_overflow_headers) + return; flush_iso_completions(ctx); + } ctx_hdr = ctx->header + ctx->header_length; ctx->last_timestamp = (u16)le32_to_cpu((__force __le32)dma_hdr[0]); @@ -2855,8 +2858,11 @@ static int handle_it_packet(struct context *context, sync_it_packet_for_cpu(context, d); - if (ctx->header_length + 4 > PAGE_SIZE) + if (ctx->header_length + 4 > PAGE_SIZE) { + if (ctx->base.drop_overflow_headers) + return 1; flush_iso_completions(ctx); + } ctx_hdr = ctx->header + ctx->header_length; ctx->last_timestamp = le16_to_cpu(last->res_count); diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h index d500369..1db453e 100644 --- a/include/linux/firewire-cdev.h +++ b/include/linux/firewire-cdev.h @@ -215,8 +215,8 @@ struct fw_cdev_event_request2 { * 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.) + * is about to overflow. (In the last case, ABI versions < 5 drop header data + * up to the next interrupt packet.) * * Isochronous transmit events (context type %FW_CDEV_ISO_CONTEXT_TRANSMIT): * diff --git a/include/linux/firewire.h b/include/linux/firewire.h index cdc9b71..4d259fc 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -409,6 +409,7 @@ struct fw_iso_context { int type; int channel; int speed; + bool drop_overflow_headers; size_t header_size; union { fw_iso_callback_t sc;