From 7889b60ee71eafaf50699a154a2455424bb92daa Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Tue, 10 Mar 2009 21:09:28 +0100 Subject: [PATCH] firewire: core: optimize propagation of BROADCAST_CHANNEL Cache the test result of whether a device implements BROADCAST_CHANNEL. This minimizes traffic on the bus after each bus reset. A majority of devices does not implement BROADCAST_CHANNEL. Remove busy retries; just rely on the hardware to retry requests to busy responders. Remove unnecessary log messages. Rename the flag is_irm to broadcast_channel_allocated to better reflect its meaning. Reset the flag earlier in fw_core_handle_bus_reset. Pass the generation down as a call parameter; that way generation can't be newer than card->broadcast_channel_allocated and device->node_id. Signed-off-by: Stefan Richter --- drivers/firewire/fw-card.c | 85 ++----------------------------- drivers/firewire/fw-device.c | 45 ++++++++++++++-- drivers/firewire/fw-device.h | 5 +- drivers/firewire/fw-topology.c | 1 + drivers/firewire/fw-transaction.h | 6 +-- 5 files changed, 52 insertions(+), 90 deletions(-) diff --git a/drivers/firewire/fw-card.c b/drivers/firewire/fw-card.c index d63d0ed9e04..8b8c8c22f0f 100644 --- a/drivers/firewire/fw-card.c +++ b/drivers/firewire/fw-card.c @@ -181,83 +181,9 @@ void fw_core_remove_descriptor(struct fw_descriptor *desc) mutex_unlock(&card_mutex); } -#define IRM_RETRIES 2 - -/* - * The abi is set by device_for_each_child(), even though we have no use - * for data, nor do we have a meaningful return value. - */ -int fw_irm_set_broadcast_channel_register(struct device *dev, void *data) +static int set_broadcast_channel(struct device *dev, void *data) { - struct fw_device *d; - int rcode; - int node_id; - int max_speed; - int retries; - int generation; - __be32 regval; - struct fw_card *card; - - d = fw_device(dev); - /* FIXME: do we need locking here? */ - generation = d->generation; - smp_rmb(); /* Ensure generation is at least as old as node_id */ - node_id = d->node_id; - max_speed = d->max_speed; - retries = IRM_RETRIES; - card = d->card; -tryagain_r: - rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST, - node_id, generation, max_speed, - CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL, - ®val, 4); - switch (rcode) { - case RCODE_BUSY: - if (retries--) - goto tryagain_r; - fw_notify("node %x read broadcast channel busy\n", - node_id); - return 0; - - default: - fw_notify("node %x read broadcast channel failed %x\n", - node_id, rcode); - return 0; - - case RCODE_COMPLETE: - /* - * Paranoid reporting of nonstandard broadcast channel - * contents goes here - */ - if (regval != cpu_to_be32(BROADCAST_CHANNEL_INITIAL)) - return 0; - break; - } - retries = IRM_RETRIES; - regval = cpu_to_be32(BROADCAST_CHANNEL_INITIAL | - BROADCAST_CHANNEL_VALID); -tryagain_w: - rcode = fw_run_transaction(card, - TCODE_WRITE_QUADLET_REQUEST, node_id, - generation, max_speed, - CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL, - ®val, 4); - switch (rcode) { - case RCODE_BUSY: - if (retries--) - goto tryagain_w; - fw_notify("node %x write broadcast channel busy\n", - node_id); - return 0; - - default: - fw_notify("node %x write broadcast channel failed %x\n", - node_id, rcode); - return 0; - - case RCODE_COMPLETE: - return 0; - } + fw_device_set_broadcast_channel(fw_device(dev), (long)data); return 0; } @@ -268,9 +194,9 @@ static void allocate_broadcast_channel(struct fw_card *card, int generation) fw_iso_resource_manage(card, generation, 1ULL << 31, &channel, &bandwidth, true); if (channel == 31) { - card->is_irm = true; - device_for_each_child(card->device, NULL, - fw_irm_set_broadcast_channel_register); + card->broadcast_channel_allocated = true; + device_for_each_child(card->device, (void *)(long)generation, + set_broadcast_channel); } } @@ -302,7 +228,6 @@ static void fw_card_bm_work(struct work_struct *work) __be32 lock_data[2]; spin_lock_irqsave(&card->lock, flags); - card->is_irm = false; if (card->local_node == NULL) { spin_unlock_irqrestore(&card->lock, flags); diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c index a40444e8eb2..a47e2129d83 100644 --- a/drivers/firewire/fw-device.c +++ b/drivers/firewire/fw-device.c @@ -518,7 +518,7 @@ static int read_bus_info_block(struct fw_device *device, int generation) kfree(old_rom); ret = 0; - device->cmc = rom[2] & 1 << 30; + device->cmc = rom[2] >> 30 & 1; out: kfree(rom); @@ -756,6 +756,44 @@ static int lookup_existing_device(struct device *dev, void *data) return match; } +enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, }; + +void fw_device_set_broadcast_channel(struct fw_device *device, int generation) +{ + struct fw_card *card = device->card; + __be32 data; + int rcode; + + if (!card->broadcast_channel_allocated) + return; + + if (device->bc_implemented == BC_UNKNOWN) { + rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST, + device->node_id, generation, device->max_speed, + CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL, + &data, 4); + switch (rcode) { + case RCODE_COMPLETE: + if (data & cpu_to_be32(1 << 31)) { + device->bc_implemented = BC_IMPLEMENTED; + break; + } + /* else fall through to case address error */ + case RCODE_ADDRESS_ERROR: + device->bc_implemented = BC_UNIMPLEMENTED; + } + } + + if (device->bc_implemented == BC_IMPLEMENTED) { + data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL | + BROADCAST_CHANNEL_VALID); + fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST, + device->node_id, generation, device->max_speed, + CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL, + &data, 4); + } +} + static void fw_device_init(struct work_struct *work) { struct fw_device *device = @@ -849,9 +887,8 @@ static void fw_device_init(struct work_struct *work) device->config_rom[3], device->config_rom[4], 1 << device->max_speed); device->config_rom_retries = 0; - if (device->card->is_irm) - fw_irm_set_broadcast_channel_register(&device->device, - NULL); + + fw_device_set_broadcast_channel(device, device->generation); } /* diff --git a/drivers/firewire/fw-device.h b/drivers/firewire/fw-device.h index 3085a74669b..97588937c01 100644 --- a/drivers/firewire/fw-device.h +++ b/drivers/firewire/fw-device.h @@ -71,7 +71,6 @@ struct fw_device { int node_id; int generation; unsigned max_speed; - bool cmc; struct fw_card *card; struct device device; @@ -81,6 +80,9 @@ struct fw_device { u32 *config_rom; size_t config_rom_length; int config_rom_retries; + unsigned cmc:1; + unsigned bc_implemented:2; + struct delayed_work work; struct fw_attribute_group attribute_group; }; @@ -109,6 +111,7 @@ static inline void fw_device_put(struct fw_device *device) struct fw_device *fw_device_get_by_devt(dev_t devt); int fw_device_enable_phys_dma(struct fw_device *device); +void fw_device_set_broadcast_channel(struct fw_device *device, int generation); void fw_device_cdev_update(struct fw_device *device); void fw_device_cdev_remove(struct fw_device *device); diff --git a/drivers/firewire/fw-topology.c b/drivers/firewire/fw-topology.c index b44131cf0c6..d0deecc4de9 100644 --- a/drivers/firewire/fw-topology.c +++ b/drivers/firewire/fw-topology.c @@ -526,6 +526,7 @@ void fw_core_handle_bus_reset(struct fw_card *card, int node_id, int generation, spin_lock_irqsave(&card->lock, flags); + card->broadcast_channel_allocated = false; card->node_id = node_id; /* * Update node_id before generation to prevent anybody from using diff --git a/drivers/firewire/fw-transaction.h b/drivers/firewire/fw-transaction.h index d4f42cecbdf..dfa799068f8 100644 --- a/drivers/firewire/fw-transaction.h +++ b/drivers/firewire/fw-transaction.h @@ -230,11 +230,6 @@ struct fw_card { u8 color; /* must be u8 to match the definition in struct fw_node */ int gap_count; bool beta_repeaters_present; - /* - * Set if the local device is the IRM and the broadcast channel - * was allocated. - */ - bool is_irm; int index; @@ -245,6 +240,7 @@ struct fw_card { int bm_retries; int bm_generation; + bool broadcast_channel_allocated; u32 broadcast_channel; u32 topology_map[(CSR_TOPOLOGY_MAP_END - CSR_TOPOLOGY_MAP) / 4]; }; -- 2.41.1