korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-17 17:24:17 +08:00
Code Issues Packages Projects Releases Wiki Activity

wimax/i2400m: Reset the TX FIFO indices when allocating the TX FIFO in tx_setup()

Browse Source 
This patch makes sure whenever tx_setup() is invoked during driver
initialization or device reset where TX FIFO is released and re-allocated,
the indices tx_in, tx_out, tx_msg_size, tx_sequence, tx_msg are properly
initialized.

When a device reset happens and the TX FIFO is released/re-allocated,
a new block of memory may be allocated for the TX FIFO, therefore tx_msg
should be cleared so that no any TX threads (tx_worker, tx) would access
to the out-of-date addresses.

Also, the TX threads use tx_in and tx_out to decide where to put the new
host-to-device messages and from where to copy them to the device HW FIFO,
these indices have to be cleared so after the TX FIFO is re-allocated during
the reset, the indices both refer to the head of the FIFO, ie. a new start.
The same rational applies to tx_msg_size and tx_sequence.

To protect the indices from being accessed by multiple threads simultaneously,
the lock tx_lock has to be obtained before the initializations and released
afterwards.

Signed-off-by: Cindy H Kao <cindy.h.kao@intel.com>
This commit is contained in:
Cindy H Kao 2010-04-23 17:19:06 -07:00 committed by Inaky Perez-Gonzalez
parent 2354161dd3
commit d94401742d
1 changed files with 21 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
drivers/net/wimax/i2400m/tx.c
View File

@ -877,27 +877,40 @@ EXPORT_SYMBOL_GPL(i2400m_tx_msg_sent);
* i2400m_tx_setup - Initialize the TX queue and infrastructure
*
* Make sure we reset the TX sequence to zero, as when this function
* is called, the firmware has been just restarted.
* is called, the firmware has been just restarted. Same rational
* for tx_in, tx_out, tx_msg_size and tx_msg. We reset them since
* the memory for TX queue is reallocated.
*/
int i2400m_tx_setup(struct i2400m *i2400m)
{
int result;
int result = 0;
void *tx_buf;
unsigned long flags;
/* Do this here only once -- can't do on
* i2400m_hard_start_xmit() as we'll cause race conditions if
* the WS was scheduled on another CPU */
INIT_WORK(&i2400m->wake_tx_ws, i2400m_wake_tx_work);
i2400m->tx_sequence = 0;
tx_buf = kmalloc(I2400M_TX_BUF_SIZE, GFP_ATOMIC);
if (tx_buf == NULL) {
result = -ENOMEM;
goto error_kmalloc;
}
/* Warn if the calculated buffer size exceeds I2400M_TX_BUF_SIZE. */
BUILD_BUG_ON(I2400M_TX_PDU_TOTAL_SIZE > I2400M_TX_BUF_SIZE);
i2400m->tx_buf = kmalloc(I2400M_TX_BUF_SIZE, GFP_KERNEL);
if (i2400m->tx_buf == NULL)
result = -ENOMEM;
else
result = 0;
spin_lock_irqsave(&i2400m->tx_lock, flags);
i2400m->tx_sequence = 0;
i2400m->tx_in = 0;
i2400m->tx_out = 0;
i2400m->tx_msg_size = 0;
i2400m->tx_msg = NULL;
i2400m->tx_buf = tx_buf;
spin_unlock_irqrestore(&i2400m->tx_lock, flags);
/* Huh? the bus layer has to define this... */
BUG_ON(i2400m->bus_tx_block_size == 0);
error_kmalloc:
return result;
}