From ec9a13cdbfc8cf29502096ca69b65f07184a9b2c Mon Sep 17 00:00:00 2001 From: Nigel Cunningham Date: Tue, 9 Dec 2008 22:40:20 +1100 Subject: [PATCH 1/2] ieee1394: node manager causes up to ~3.25s delay in freezing tasks The firewire nodemanager function "nodemgr_host_thread" contains a loop that calls try_to_freeze near the top of the loop, but then delays for up to 3.25 seconds (plus time to do work) before getting back to the top of the loop. When starting a cycle post-boot, this doesn't seem to bite, but it is causing a noticeable delay at boot time, when freezing processes prior to starting to read the image. The following patch adds invocation of try_to_freeze to the subloops that are used in the body of this function. With these additions, the time to freeze when starting to resume at boot time is virtually zero. I'm no expert on firewire, and so don't know that we shouldn't check the return value and jump back to the top of the loop or such like after being frozen, but I submit it for your consideration. Signed-off-by: Nigel Cunningham The delay until nodemgr freezes was up to 0.25s (plus time for node probes) in Linux 2.6.27 and older and up to 3.25s (plus ~) since Linux 2.6.28-rc1, hence much more noticeable. try_to_freeze() without any jump is correct. The surrounding code in the respective loops will catch whether another bus reset happens during the freeze and handle it. Signed-off-by: Stefan Richter --- drivers/ieee1394/nodemgr.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/ieee1394/nodemgr.c b/drivers/ieee1394/nodemgr.c index 9e39f73282ee..d333ae22459c 100644 --- a/drivers/ieee1394/nodemgr.c +++ b/drivers/ieee1394/nodemgr.c @@ -1685,6 +1685,7 @@ static int nodemgr_host_thread(void *data) g = get_hpsb_generation(host); for (i = 0; i < 4 ; i++) { msleep_interruptible(63); + try_to_freeze(); if (kthread_should_stop()) goto exit; @@ -1725,6 +1726,7 @@ static int nodemgr_host_thread(void *data) /* Sleep 3 seconds */ for (i = 3000/200; i; i--) { msleep_interruptible(200); + try_to_freeze(); if (kthread_should_stop()) goto exit; From 1d1dc5e83f3299c108a4e44d58cc4bfef48c876a Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Wed, 10 Dec 2008 00:20:38 +0100 Subject: [PATCH 2/2] firewire: fw-ohci: fix IOMMU resource exhaustion There is a DMA map/ unmap imbalance whenever a block write request packet is sent and then dequeued with ohci_cancel_packet. The latter may happen frequently if the AR resp tasklet is executed before the AT req tasklet for the same transaction. Add the missing dma_unmap_single. This fixes https://bugzilla.redhat.com/show_bug.cgi?id=475156 Reported-by: Emmanuel Kowalski Tested-by: Emmanuel Kowalski Signed-off-by: Stefan Richter --- drivers/firewire/fw-ohci.c | 11 +++++++---- drivers/firewire/fw-transaction.c | 3 +++ drivers/firewire/fw-transaction.h | 2 ++ 3 files changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c index 46610b090415..ab9c01e462ef 100644 --- a/drivers/firewire/fw-ohci.c +++ b/drivers/firewire/fw-ohci.c @@ -974,6 +974,7 @@ at_context_queue_packet(struct context *ctx, struct fw_packet *packet) packet->ack = RCODE_SEND_ERROR; return -1; } + packet->payload_bus = payload_bus; d[2].req_count = cpu_to_le16(packet->payload_length); d[2].data_address = cpu_to_le32(payload_bus); @@ -1025,7 +1026,6 @@ static int handle_at_packet(struct context *context, struct driver_data *driver_data; struct fw_packet *packet; struct fw_ohci *ohci = context->ohci; - dma_addr_t payload_bus; int evt; if (last->transfer_status == 0) @@ -1038,9 +1038,8 @@ static int handle_at_packet(struct context *context, /* This packet was cancelled, just continue. */ return 1; - payload_bus = le32_to_cpu(last->data_address); - if (payload_bus != 0) - dma_unmap_single(ohci->card.device, payload_bus, + if (packet->payload_bus) + dma_unmap_single(ohci->card.device, packet->payload_bus, packet->payload_length, DMA_TO_DEVICE); evt = le16_to_cpu(last->transfer_status) & 0x1f; @@ -1697,6 +1696,10 @@ static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet) if (packet->ack != 0) goto out; + if (packet->payload_bus) + dma_unmap_single(ohci->card.device, packet->payload_bus, + packet->payload_length, DMA_TO_DEVICE); + log_ar_at_event('T', packet->speed, packet->header, 0x20); driver_data->packet = NULL; packet->ack = RCODE_CANCELLED; diff --git a/drivers/firewire/fw-transaction.c b/drivers/firewire/fw-transaction.c index 022ac4fabb67..2884f876397b 100644 --- a/drivers/firewire/fw-transaction.c +++ b/drivers/firewire/fw-transaction.c @@ -207,6 +207,7 @@ fw_fill_request(struct fw_packet *packet, int tcode, int tlabel, packet->speed = speed; packet->generation = generation; packet->ack = 0; + packet->payload_bus = 0; } /** @@ -581,6 +582,8 @@ fw_fill_response(struct fw_packet *response, u32 *request_header, BUG(); return; } + + response->payload_bus = 0; } EXPORT_SYMBOL(fw_fill_response); diff --git a/drivers/firewire/fw-transaction.h b/drivers/firewire/fw-transaction.h index aed7dbb17cda..839466f0a795 100644 --- a/drivers/firewire/fw-transaction.h +++ b/drivers/firewire/fw-transaction.h @@ -27,6 +27,7 @@ #include #include #include +#include #include #define TCODE_IS_READ_REQUEST(tcode) (((tcode) & ~1) == 4) @@ -153,6 +154,7 @@ struct fw_packet { size_t header_length; void *payload; size_t payload_length; + dma_addr_t payload_bus; u32 timestamp; /*