I have tried many solutions, the two last solutions (work_queue and
kernel_thread)
seem to have the same poor performances.
Does anyone have another idea ?
Thanks in advance.
Laurent
PS : eth_init_rx_bd function can allocate a new skbuff (YES parameter) or
re-use
the previous skbuff allocated to a rx buffer descriptor(NO parameter).
1) tasklet : runs in interrupt context and
then doesn't support semaphore down function.
2) work_queue : doesn't run in interrupt context
and supports semaphore down function.
static irqreturn_t eth_interrupt (int irq, void * dev_id, struct pt_regs *
regs)
{
DRV_ETH_INFO *info = (DRV_ETH_INFO *)dev_id;
unsigned short events;
/* get pending events */
events = info->eth_reg->fcc_fcce & info->eth_reg->fcc_fccm;
/* ack pending events */
info->eth_reg->fcc_fcce = events;
/* mask interrupts */
info->eth_reg->fcc_fccm = ~events;
/* check events */
if (BTST(FCC_ENET_RXF, events))
tasklet_schedule(&Info_low->recvTasklet);
if (BTST(FCC_ENET_TXE|FCC_ENET_TXB, events))
tasklet_schedule(&Info_low->xmitEndTasklet);
return(IRQ_HANDLED);
}
static void eth_rx_event (DRV_ETH_INFO *info)
{
ETH_BD_MGT_TABLE *bd_table = &info->eth_bd_table;
ETH_BD_MGT *bd_mgt = &bd_table->rx[bd_table->rx_out];
struct sk_buff *skb;
/* check empty status */
while(BTST(BD_ENET_RX_EMPTY, bd_mgt->bd->cbd_sc) == 0) {
/* check error and upper layer status */
if
(BTST((BD_ENET_RX_LG|BD_ENET_RX_SH|BD_ENET_RX_NO|BD_ENET_RX_CR|BD_ENET_RX_OV
|BD_ENET_RX_CL), bd_mgt->bd->cbd_sc)) {
/* re-enable bd with current buffer */
eth_init_rx_bd(info, bd_mgt, NO); /* always return without error
*/
} else {
/* save current segment */
skb = (struct sk_buff *)bd_mgt->segment;
skb->len = bd_mgt->bd->cbd_datlen;
/* get a new buffer for this bd */
if (eth_init_rx_bd(info, bd_mgt, YES) == BRG_NO_ERROR) {
/* fill sk_buff parameters */
skb->dev = info->dev;
skb->protocol = eth_type_trans(skb, info->dev);
/* send frame to upper layers that use semaphores */
netif_packet(skb);
} else {
/* re-enable bd with current buffer */
eth_init_rx_bd(info, bd_mgt, NO); /* always return without
error */
}
}
/* set next index */
bd_table->rx_out = (bd_table->rx_out == (ETH_RX_BD_NUMBER -
1))?0:(bd_table->rx_out + 1);
/* get next bd mgt pointer */
bd_mgt = &bd_table->rx[bd_table->rx_out];
}
/* enable interruption*/
info->eth_reg->fcc_fccm |= FCC_ENET_RXF;
return;
}
3) kernel_thread : doesn't run in interrupt context
and supports semaphore down function. I have tried to
change many task parameters :
task->policy = SCHED_RR;
task->static_prio = 100;
task->prio = 100;
task->rt_priority = 1;
To synchronize the rx interrruption and the thread I have tried completion
and semaphore mecanism without any difference
static irqreturn_t eth_interrupt (int irq, void * dev_id, struct pt_regs *
regs)
{
DRV_ETH_INFO *info = (DRV_ETH_INFO *)dev_id;
USHORT events;
/* get pending events */
events = info->eth_reg->fcc_fcce & info->eth_reg->fcc_fccm;
/* ack pending events */
info->eth_reg->fcc_fcce = events;
/* mask interrupts */
info->eth_reg->fcc_fccm = ~events;
/* check events */
if (BTST(FCC_ENET_RXF, events)) osSemSignal(Info_low->recvSem);
if (BTST(FCC_ENET_TXE|FCC_ENET_TXB, events))
osSemSignal(Info_low->xmitEndSem);
return(IRQ_HANDLED);
}
unsigned eth_recv_task (void* data)
{
DRV_ETH_INFO *info = (DRV_ETH_INFO
*)Info_low->drv_eth_info;
ETH_BD_MGT_TABLE *bd_table = &info->eth_bd_table;
ETH_BD_MGT *bd_mgt = &bd_table->rx[bd_table->rx_out];
while(1) {
/* wait interrupt */
osSemWait(Info_low->recvSem, 0);
/* check empty status */
while(BTST(BD_ENET_RX_EMPTY, bd_mgt->bd->cbd_sc) == 0) {
/* check error and upper layer status */
if
(BTST((BD_ENET_RX_LG|BD_ENET_RX_SH|BD_ENET_RX_NO|BD_ENET_RX_CR|BD_ENET_RX_OV
|BD_ENET_RX_CL), bd_mgt->bd->cbd_sc)) {
/* re-enable bd with current buffer */
eth_init_rx_bd(info, bd_mgt, NO); /* always return without
error */
} else {
/* save current segment */
skb = (struct sk_buff *)bd_mgt->segment;
skb->len = bd_mgt->bd->cbd_datlen - 4;
/* get a new buffer for this bd */
if (eth_init_rx_bd(info, bd_mgt, YES) == BRG_NO_ERROR) {
/* fill sk_buff parameters */
skb->dev = info->dev;
skb->protocol = eth_type_trans(skb, info->dev);
/* send frame to upper layers that use semaphores */
netif_packet(skb);
} else {
/* re-enable bd with current buffer */
eth_init_rx_bd(info, bd_mgt, NO); /* always return without
error */
}
/* set next index */
bd_table->rx_out = (bd_table->rx_out == (ETH_RX_BD_NUMBER -
1))?0:(bd_table->rx_out + 1);
/* get next bd mgt pointer */
bd_mgt = &bd_table->rx[bd_table->rx_out];
}
/* enable interrupt */
info->eth_reg->fcc_fccm |= FCC_ENET_RXF;
}
return(0);
}
