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Message-ID: <tkrat.a5203b3380577b04@s5r6.in-berlin.de>
Date: Tue, 10 Mar 2009 21:09:28 +0100 (CET)
From: Stefan Richter <stefanr@...6.in-berlin.de>
To: linux1394-devel@...ts.sourceforge.net
cc: linux-kernel@...r.kernel.org
Subject: [PATCH 4/5] 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 <stefanr@...6.in-berlin.de>
---
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(-)
Index: linux/drivers/firewire/fw-card.c
===================================================================
--- linux.orig/drivers/firewire/fw-card.c
+++ linux/drivers/firewire/fw-card.c
@@ -181,83 +181,9 @@ void fw_core_remove_descriptor(struct fw
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(s
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_
__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);
Index: linux/drivers/firewire/fw-device.c
===================================================================
--- linux.orig/drivers/firewire/fw-device.c
+++ linux/drivers/firewire/fw-device.c
@@ -518,7 +518,7 @@ static int read_bus_info_block(struct fw
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
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_s
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);
}
/*
Index: linux/drivers/firewire/fw-device.h
===================================================================
--- linux.orig/drivers/firewire/fw-device.h
+++ linux/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
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);
Index: linux/drivers/firewire/fw-topology.c
===================================================================
--- linux.orig/drivers/firewire/fw-topology.c
+++ linux/drivers/firewire/fw-topology.c
@@ -526,6 +526,7 @@ void fw_core_handle_bus_reset(struct fw_
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
Index: linux/drivers/firewire/fw-transaction.h
===================================================================
--- linux.orig/drivers/firewire/fw-transaction.h
+++ linux/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];
};
--
Stefan Richter
-=====-==--= --== -=-=-
http://arcgraph.de/sr/
--
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