2010-04-02 20:39:11

by Reinette Chatre

[permalink] [raw]
Subject: [PATCH 0/3] iwlwifi fixes for 2.6.34

We include three fixes. Included is a fix for some DMA issues discovered
while running with CONFIG_DMA_API_DEBUG where some memory was not unmapped
when driver is unloaded. We also include a fix for a potential BUG_ON in
rate scaling. The third fix eliminates the need for the driver to allocate
a large memory area on resume, which has been causing some memory
allocation issues.

These patches are also available from wireless-2.6 branch on
git://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/iwlwifi-2.6.git

Shanyu Zhao (1):
iwlwifi: use consistent table for tx data collect

Zhu Yi (2):
iwlwifi: fix DMA allocation warnings
iwlwifi: avoid Tx queue memory allocation in interface down

drivers/net/wireless/iwlwifi/iwl-agn-rs.c | 55 +++++++--------
drivers/net/wireless/iwlwifi/iwl-core.c | 11 ++-
drivers/net/wireless/iwlwifi/iwl-core.h | 5 +-
drivers/net/wireless/iwlwifi/iwl-tx.c | 107 +++++++++++++++++++++++++----
4 files changed, 129 insertions(+), 49 deletions(-)



2010-04-02 20:39:14

by Reinette Chatre

[permalink] [raw]
Subject: [PATCH 3/3] iwlwifi: avoid Tx queue memory allocation in interface down

From: Zhu Yi <[email protected]>

We used to free all the Tx queues memory when interface is brought
down and reallocate them again in interface up. This requires
order-4 allocation for txq->cmd[]. In situations like s2ram, this
usually leads to allocation failure in the memory subsystem. The
patch fixed this problem by allocating the Tx queues memory only at
the first time. Later iwl_down/iwl_up only initialize but don't
free and reallocate them. The memory is freed at the device removal
time. BTW, we have already done this for the Rx queue.

This fixed bug https://bugzilla.kernel.org/show_bug.cgi?id=15551

Signed-off-by: Zhu Yi <[email protected]>
Acked-by: Wey-Yi Guy <[email protected]>
Signed-off-by: Reinette Chatre <[email protected]>
---
drivers/net/wireless/iwlwifi/iwl-core.c | 11 ++++--
drivers/net/wireless/iwlwifi/iwl-core.h | 5 ++-
drivers/net/wireless/iwlwifi/iwl-tx.c | 59 +++++++++++++++++++++++++-----
3 files changed, 60 insertions(+), 15 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c
index 112149e..894bcb8 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.c
+++ b/drivers/net/wireless/iwlwifi/iwl-core.c
@@ -307,10 +307,13 @@ int iwl_hw_nic_init(struct iwl_priv *priv)

spin_unlock_irqrestore(&priv->lock, flags);

- /* Allocate and init all Tx and Command queues */
- ret = iwl_txq_ctx_reset(priv);
- if (ret)
- return ret;
+ /* Allocate or reset and init all Tx and Command queues */
+ if (!priv->txq) {
+ ret = iwl_txq_ctx_alloc(priv);
+ if (ret)
+ return ret;
+ } else
+ iwl_txq_ctx_reset(priv);

set_bit(STATUS_INIT, &priv->status);

diff --git a/drivers/net/wireless/iwlwifi/iwl-core.h b/drivers/net/wireless/iwlwifi/iwl-core.h
index 4ef7739..732590f 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.h
+++ b/drivers/net/wireless/iwlwifi/iwl-core.h
@@ -442,7 +442,8 @@ void iwl_rx_csa(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb);
/*****************************************************
* TX
******************************************************/
-int iwl_txq_ctx_reset(struct iwl_priv *priv);
+int iwl_txq_ctx_alloc(struct iwl_priv *priv);
+void iwl_txq_ctx_reset(struct iwl_priv *priv);
void iwl_hw_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq);
int iwl_hw_txq_attach_buf_to_tfd(struct iwl_priv *priv,
struct iwl_tx_queue *txq,
@@ -456,6 +457,8 @@ void iwl_free_tfds_in_queue(struct iwl_priv *priv,
void iwl_txq_update_write_ptr(struct iwl_priv *priv, struct iwl_tx_queue *txq);
int iwl_tx_queue_init(struct iwl_priv *priv, struct iwl_tx_queue *txq,
int slots_num, u32 txq_id);
+void iwl_tx_queue_reset(struct iwl_priv *priv, struct iwl_tx_queue *txq,
+ int slots_num, u32 txq_id);
void iwl_tx_queue_free(struct iwl_priv *priv, int txq_id);
int iwl_tx_agg_start(struct iwl_priv *priv, const u8 *ra, u16 tid, u16 *ssn);
int iwl_tx_agg_stop(struct iwl_priv *priv , const u8 *ra, u16 tid);
diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index 6aa3090..343d81a 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -433,6 +433,26 @@ out_free_arrays:
}
EXPORT_SYMBOL(iwl_tx_queue_init);

+void iwl_tx_queue_reset(struct iwl_priv *priv, struct iwl_tx_queue *txq,
+ int slots_num, u32 txq_id)
+{
+ int actual_slots = slots_num;
+
+ if (txq_id == IWL_CMD_QUEUE_NUM)
+ actual_slots++;
+
+ memset(txq->meta, 0, sizeof(struct iwl_cmd_meta) * actual_slots);
+
+ txq->need_update = 0;
+
+ /* Initialize queue's high/low-water marks, and head/tail indexes */
+ iwl_queue_init(priv, &txq->q, TFD_QUEUE_SIZE_MAX, slots_num, txq_id);
+
+ /* Tell device where to find queue */
+ priv->cfg->ops->lib->txq_init(priv, txq);
+}
+EXPORT_SYMBOL(iwl_tx_queue_reset);
+
/**
* iwl_hw_txq_ctx_free - Free TXQ Context
*
@@ -444,8 +464,7 @@ void iwl_hw_txq_ctx_free(struct iwl_priv *priv)

/* Tx queues */
if (priv->txq) {
- for (txq_id = 0; txq_id < priv->hw_params.max_txq_num;
- txq_id++)
+ for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++)
if (txq_id == IWL_CMD_QUEUE_NUM)
iwl_cmd_queue_free(priv);
else
@@ -461,15 +480,15 @@ void iwl_hw_txq_ctx_free(struct iwl_priv *priv)
EXPORT_SYMBOL(iwl_hw_txq_ctx_free);

/**
- * iwl_txq_ctx_reset - Reset TX queue context
- * Destroys all DMA structures and initialize them again
+ * iwl_txq_ctx_alloc - allocate TX queue context
+ * Allocate all Tx DMA structures and initialize them
*
* @param priv
* @return error code
*/
-int iwl_txq_ctx_reset(struct iwl_priv *priv)
+int iwl_txq_ctx_alloc(struct iwl_priv *priv)
{
- int ret = 0;
+ int ret;
int txq_id, slots_num;
unsigned long flags;

@@ -527,8 +546,31 @@ int iwl_txq_ctx_reset(struct iwl_priv *priv)
return ret;
}

+void iwl_txq_ctx_reset(struct iwl_priv *priv)
+{
+ int txq_id, slots_num;
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->lock, flags);
+
+ /* Turn off all Tx DMA fifos */
+ priv->cfg->ops->lib->txq_set_sched(priv, 0);
+
+ /* Tell NIC where to find the "keep warm" buffer */
+ iwl_write_direct32(priv, FH_KW_MEM_ADDR_REG, priv->kw.dma >> 4);
+
+ spin_unlock_irqrestore(&priv->lock, flags);
+
+ /* Alloc and init all Tx queues, including the command queue (#4) */
+ for (txq_id = 0; txq_id < priv->hw_params.max_txq_num; txq_id++) {
+ slots_num = txq_id == IWL_CMD_QUEUE_NUM ?
+ TFD_CMD_SLOTS : TFD_TX_CMD_SLOTS;
+ iwl_tx_queue_reset(priv, &priv->txq[txq_id], slots_num, txq_id);
+ }
+}
+
/**
- * iwl_txq_ctx_stop - Stop all Tx DMA channels, free Tx queue memory
+ * iwl_txq_ctx_stop - Stop all Tx DMA channels
*/
void iwl_txq_ctx_stop(struct iwl_priv *priv)
{
@@ -548,9 +590,6 @@ void iwl_txq_ctx_stop(struct iwl_priv *priv)
1000);
}
spin_unlock_irqrestore(&priv->lock, flags);
-
- /* Deallocate memory for all Tx queues */
- iwl_hw_txq_ctx_free(priv);
}
EXPORT_SYMBOL(iwl_txq_ctx_stop);

--
1.6.3.3


2010-04-02 20:39:12

by Reinette Chatre

[permalink] [raw]
Subject: [PATCH 2/3] iwlwifi: use consistent table for tx data collect

From: Shanyu Zhao <[email protected]>

When collecting tx data for non-aggregation packets in rate scaling, if
the tx data matches "other table", it still uses current table to update
the stats and calculate average throughput in function rs_collect_tx_data().
This can mess up the rate scaling data structure and cause a kernel panic
in a BUG_ON statement in rs_rate_scale_perform().

To fix this bug, we pass table pointer instead of window pointer (pointed
to by table pointer) to function rs_collect_tx_data() so that the table
being used is consistent.

Signed-off-by: Shanyu Zhao <[email protected]>
Signed-off-by: Henry Zhang <[email protected]>
Signed-off-by: Reinette Chatre <[email protected]>
---
drivers/net/wireless/iwlwifi/iwl-agn-rs.c | 55 ++++++++++++----------------
1 files changed, 24 insertions(+), 31 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
index 8bf7c20..be00cb3 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
@@ -345,6 +345,17 @@ static inline int get_num_of_ant_from_rate(u32 rate_n_flags)
!!(rate_n_flags & RATE_MCS_ANT_C_MSK);
}

+/*
+ * Static function to get the expected throughput from an iwl_scale_tbl_info
+ * that wraps a NULL pointer check
+ */
+static s32 get_expected_tpt(struct iwl_scale_tbl_info *tbl, int rs_index)
+{
+ if (tbl->expected_tpt)
+ return tbl->expected_tpt[rs_index];
+ return 0;
+}
+
/**
* rs_collect_tx_data - Update the success/failure sliding window
*
@@ -352,19 +363,21 @@ static inline int get_num_of_ant_from_rate(u32 rate_n_flags)
* at this rate. window->data contains the bitmask of successful
* packets.
*/
-static int rs_collect_tx_data(struct iwl_rate_scale_data *windows,
- int scale_index, s32 tpt, int attempts,
- int successes)
+static int rs_collect_tx_data(struct iwl_scale_tbl_info *tbl,
+ int scale_index, int attempts, int successes)
{
struct iwl_rate_scale_data *window = NULL;
static const u64 mask = (((u64)1) << (IWL_RATE_MAX_WINDOW - 1));
- s32 fail_count;
+ s32 fail_count, tpt;

if (scale_index < 0 || scale_index >= IWL_RATE_COUNT)
return -EINVAL;

/* Select window for current tx bit rate */
- window = &(windows[scale_index]);
+ window = &(tbl->win[scale_index]);
+
+ /* Get expected throughput */
+ tpt = get_expected_tpt(tbl, scale_index);

/*
* Keep track of only the latest 62 tx frame attempts in this rate's
@@ -738,16 +751,6 @@ static bool table_type_matches(struct iwl_scale_tbl_info *a,
return (a->lq_type == b->lq_type) && (a->ant_type == b->ant_type) &&
(a->is_SGI == b->is_SGI);
}
-/*
- * Static function to get the expected throughput from an iwl_scale_tbl_info
- * that wraps a NULL pointer check
- */
-static s32 get_expected_tpt(struct iwl_scale_tbl_info *tbl, int rs_index)
-{
- if (tbl->expected_tpt)
- return tbl->expected_tpt[rs_index];
- return 0;
-}

/*
* mac80211 sends us Tx status
@@ -764,12 +767,10 @@ static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband,
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
struct iwl_priv *priv = (struct iwl_priv *)priv_r;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
- struct iwl_rate_scale_data *window = NULL;
enum mac80211_rate_control_flags mac_flags;
u32 tx_rate;
struct iwl_scale_tbl_info tbl_type;
- struct iwl_scale_tbl_info *curr_tbl, *other_tbl;
- s32 tpt = 0;
+ struct iwl_scale_tbl_info *curr_tbl, *other_tbl, *tmp_tbl;

IWL_DEBUG_RATE_LIMIT(priv, "get frame ack response, update rate scale window\n");

@@ -852,7 +853,6 @@ static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband,
IWL_DEBUG_RATE(priv, "Neither active nor search matches tx rate\n");
return;
}
- window = (struct iwl_rate_scale_data *)&(curr_tbl->win[0]);

/*
* Updating the frame history depends on whether packets were
@@ -865,8 +865,7 @@ static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband,
tx_rate = le32_to_cpu(table->rs_table[0].rate_n_flags);
rs_get_tbl_info_from_mcs(tx_rate, priv->band, &tbl_type,
&rs_index);
- tpt = get_expected_tpt(curr_tbl, rs_index);
- rs_collect_tx_data(window, rs_index, tpt,
+ rs_collect_tx_data(curr_tbl, rs_index,
info->status.ampdu_ack_len,
info->status.ampdu_ack_map);

@@ -896,19 +895,13 @@ static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband,
* table as active/search.
*/
if (table_type_matches(&tbl_type, curr_tbl))
- tpt = get_expected_tpt(curr_tbl, rs_index);
+ tmp_tbl = curr_tbl;
else if (table_type_matches(&tbl_type, other_tbl))
- tpt = get_expected_tpt(other_tbl, rs_index);
+ tmp_tbl = other_tbl;
else
continue;
-
- /* Constants mean 1 transmission, 0 successes */
- if (i < retries)
- rs_collect_tx_data(window, rs_index, tpt, 1,
- 0);
- else
- rs_collect_tx_data(window, rs_index, tpt, 1,
- legacy_success);
+ rs_collect_tx_data(tmp_tbl, rs_index, 1,
+ i < retries ? 0 : legacy_success);
}

/* Update success/fail counts if not searching for new mode */
--
1.6.3.3


2010-04-02 20:39:12

by Reinette Chatre

[permalink] [raw]
Subject: [PATCH 1/3] iwlwifi: fix DMA allocation warnings

From: Zhu Yi <[email protected]>

Below warning is triggered sometimes at module removal time when
CONFIG_DMA_API_DEBUG is enabled. This should be caused by we didn't
unmap pending commands (enqueued, but no complete notification
received) for the Tx command queue.

[ 1583.107469] ------------[ cut here ]------------
[ 1583.107539] WARNING: at lib/dma-debug.c:688
dma_debug_device_change+0x13c/0x180()
[ 1583.107617] Hardware name: ...
[ 1583.107664] pci 0000:04:00.0: DMA-API: device driver has pending DMA
allocations while released from device [count=1]
[ 1583.107713] Modules linked in: ...
[ 1583.111661] Pid: 16970, comm: modprobe Tainted: G W
2.6.34-rc1-wl #33
[ 1583.111727] Call Trace:
[ 1583.111779] [<c02a281c>] ? dma_debug_device_change+0x13c/0x180
[ 1583.111833] [<c02a281c>] ? dma_debug_device_change+0x13c/0x180
[ 1583.111908] [<c0138e11>] warn_slowpath_common+0x71/0xd0
[ 1583.111963] [<c02a281c>] ? dma_debug_device_change+0x13c/0x180
[ 1583.112016] [<c0138ebb>] warn_slowpath_fmt+0x2b/0x30
[ 1583.112086] [<c02a281c>] dma_debug_device_change+0x13c/0x180
[ 1583.112142] [<c03e6c33>] notifier_call_chain+0x53/0x90
[ 1583.112198] [<c03e1ebe>] ? down_read+0x6e/0x90
[ 1583.112271] [<c015b229>] __blocking_notifier_call_chain+0x49/0x70
[ 1583.112326] [<c015b26f>] blocking_notifier_call_chain+0x1f/0x30
[ 1583.112380] [<c031931c>] __device_release_driver+0x8c/0xa0
[ 1583.112451] [<c03193bf>] driver_detach+0x8f/0xa0
[ 1583.112538] [<c0318382>] bus_remove_driver+0x82/0x100
[ 1583.112595] [<c0319ad9>] driver_unregister+0x49/0x80
[ 1583.112671] [<c024feb2>] ? sysfs_remove_file+0x12/0x20
[ 1583.112727] [<c02aa292>] pci_unregister_driver+0x32/0x80
[ 1583.112791] [<fc13a3c1>] iwl_exit+0x12/0x19 [iwlagn]
[ 1583.112848] [<c017940a>] sys_delete_module+0x15a/0x210
[ 1583.112870] [<c015a5db>] ? up_read+0x1b/0x30
[ 1583.112893] [<c029600c>] ? trace_hardirqs_off_thunk+0xc/0x10
[ 1583.112924] [<c0295ffc>] ? trace_hardirqs_on_thunk+0xc/0x10
[ 1583.112947] [<c03e6a1f>] ? do_page_fault+0x1ff/0x3c0
[ 1583.112978] [<c03e36f6>] ? restore_all_notrace+0x0/0x18
[ 1583.113002] [<c016aa70>] ? trace_hardirqs_on_caller+0x20/0x190
[ 1583.113025] [<c0102d58>] sysenter_do_call+0x12/0x38
[ 1583.113054] ---[ end trace fc23e059cc4c2ced ]---

Signed-off-by: Zhu Yi <[email protected]>
Signed-off-by: Reinette Chatre <[email protected]>
---
drivers/net/wireless/iwlwifi/iwl-tx.c | 48 ++++++++++++++++++++++++++++++--
1 files changed, 45 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index 8c12311..6aa3090 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -193,10 +193,34 @@ void iwl_cmd_queue_free(struct iwl_priv *priv)
struct iwl_queue *q = &txq->q;
struct device *dev = &priv->pci_dev->dev;
int i;
+ bool huge = false;

if (q->n_bd == 0)
return;

+ for (; q->read_ptr != q->write_ptr;
+ q->read_ptr = iwl_queue_inc_wrap(q->read_ptr, q->n_bd)) {
+ /* we have no way to tell if it is a huge cmd ATM */
+ i = get_cmd_index(q, q->read_ptr, 0);
+
+ if (txq->meta[i].flags & CMD_SIZE_HUGE) {
+ huge = true;
+ continue;
+ }
+
+ pci_unmap_single(priv->pci_dev,
+ pci_unmap_addr(&txq->meta[i], mapping),
+ pci_unmap_len(&txq->meta[i], len),
+ PCI_DMA_BIDIRECTIONAL);
+ }
+ if (huge) {
+ i = q->n_window;
+ pci_unmap_single(priv->pci_dev,
+ pci_unmap_addr(&txq->meta[i], mapping),
+ pci_unmap_len(&txq->meta[i], len),
+ PCI_DMA_BIDIRECTIONAL);
+ }
+
/* De-alloc array of command/tx buffers */
for (i = 0; i <= TFD_CMD_SLOTS; i++)
kfree(txq->cmd[i]);
@@ -1049,6 +1073,14 @@ int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd)

spin_lock_irqsave(&priv->hcmd_lock, flags);

+ /* If this is a huge cmd, mark the huge flag also on the meta.flags
+ * of the _original_ cmd. This is used for DMA mapping clean up.
+ */
+ if (cmd->flags & CMD_SIZE_HUGE) {
+ idx = get_cmd_index(q, q->write_ptr, 0);
+ txq->meta[idx].flags = CMD_SIZE_HUGE;
+ }
+
idx = get_cmd_index(q, q->write_ptr, cmd->flags & CMD_SIZE_HUGE);
out_cmd = txq->cmd[idx];
out_meta = &txq->meta[idx];
@@ -1226,6 +1258,7 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
bool huge = !!(pkt->hdr.sequence & SEQ_HUGE_FRAME);
struct iwl_device_cmd *cmd;
struct iwl_cmd_meta *meta;
+ struct iwl_tx_queue *txq = &priv->txq[IWL_CMD_QUEUE_NUM];

/* If a Tx command is being handled and it isn't in the actual
* command queue then there a command routing bug has been introduced
@@ -1239,9 +1272,17 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
return;
}

- cmd_index = get_cmd_index(&priv->txq[IWL_CMD_QUEUE_NUM].q, index, huge);
- cmd = priv->txq[IWL_CMD_QUEUE_NUM].cmd[cmd_index];
- meta = &priv->txq[IWL_CMD_QUEUE_NUM].meta[cmd_index];
+ /* If this is a huge cmd, clear the huge flag on the meta.flags
+ * of the _original_ cmd. So that iwl_cmd_queue_free won't unmap
+ * the DMA buffer for the scan (huge) command.
+ */
+ if (huge) {
+ cmd_index = get_cmd_index(&txq->q, index, 0);
+ txq->meta[cmd_index].flags = 0;
+ }
+ cmd_index = get_cmd_index(&txq->q, index, huge);
+ cmd = txq->cmd[cmd_index];
+ meta = &txq->meta[cmd_index];

pci_unmap_single(priv->pci_dev,
pci_unmap_addr(meta, mapping),
@@ -1263,6 +1304,7 @@ void iwl_tx_cmd_complete(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb)
get_cmd_string(cmd->hdr.cmd));
wake_up_interruptible(&priv->wait_command_queue);
}
+ meta->flags = 0;
}
EXPORT_SYMBOL(iwl_tx_cmd_complete);

--
1.6.3.3