[PATCH net-next-2.6 5/17 v3] can: EG20T PCH: Delete unnecessary spin_lock

Tomoya MORINAGA
2010-11-24T12:16:27Z

Delete unnecessary spin_lock for accessing Message Object.
Since all message objects are divided into tx/rx area completely,
spin_lock processing is unnecessary.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
---
drivers/net/can/pch_can.c | 31 -------------------------------
1 files changed, 0 insertions(+), 31 deletions(-)

diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index 7c182b8..843bbce 100644
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -176,7 +176,6 @@ struct pch_can_priv {
unsigned int int_enables;
unsigned int int_stat;
struct net_device *ndev;
- spinlock_t msgif_reg_lock; /* Message Interface Registers Access Lock*/
unsigned int msg_obj[PCH_TX_OBJ_END];
struct pch_can_regs __iomem *regs;
struct napi_struct napi;
@@ -307,7 +306,6 @@ static void pch_can_check_if_busy(u32 __iomem
*creq_addr, u32 num)
static void pch_can_set_rxtx(struct pch_can_priv *priv, u32 buff_num,
int set, enum pch_ifreg dir)
{
- unsigned long flags;
u32 ie;

if (dir)
@@ -315,7 +313,6 @@ static void pch_can_set_rxtx(struct pch_can_priv
*priv, u32 buff_num,
else
ie = PCH_IF_MCONT_RXIE;

- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
/* Reading the receive buffer data from RAM to Interface1 registers */
iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[dir].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[dir].creq, buff_num);
@@ -336,7 +333,6 @@ static void pch_can_set_rxtx(struct pch_can_priv
*priv, u32 buff_num,
}

pch_can_check_if_busy(&priv->regs->ifregs[dir].creq, buff_num);
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
}

@@ -360,7 +356,6 @@ static void pch_can_set_tx_all(struct pch_can_priv
*priv, int set)

static u32 pch_can_get_rxtx_ir(struct pch_can_priv *priv, u32 buff_num,
u32 dir)
{
- unsigned long flags;
u32 ie, enable;

if (dir)
@@ -368,7 +363,6 @@ static u32 pch_can_get_rxtx_ir(struct pch_can_priv
*priv, u32 buff_num, u32 dir)
else
ie = PCH_IF_MCONT_TXIE;

- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[dir].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[dir].creq, buff_num);

@@ -378,7 +372,6 @@ static u32 pch_can_get_rxtx_ir(struct pch_can_priv
*priv, u32 buff_num, u32 dir)
} else {
enable = 0;
}
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
return enable;
}

@@ -390,9 +383,6 @@ static int pch_can_int_pending(struct pch_can_priv
*priv)
static void pch_can_set_rx_buffer_link(struct pch_can_priv *priv,
u32 buffer_num, int set)
{
- unsigned long flags;
-
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[0].creq, buffer_num);
iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL,
@@ -404,15 +394,12 @@ static void pch_can_set_rx_buffer_link(struct
pch_can_priv *priv,
pch_can_bit_set(&priv->regs->ifregs[0].mcont, PCH_IF_MCONT_EOB);

pch_can_check_if_busy(&priv->regs->ifregs[0].creq, buffer_num);
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
}

static u32 pch_can_get_rx_buffer_link(struct pch_can_priv *priv, u32
buffer_num)
{
- unsigned long flags;
u32 link;

- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[0].creq, buffer_num);

@@ -420,7 +407,6 @@ static u32 pch_can_get_rx_buffer_link(struct
pch_can_priv *priv, u32 buffer_num)
link = 0;
else
link = 1;
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
return link;
}

@@ -466,9 +452,6 @@ static void pch_can_clear_buffers(struct
pch_can_priv *priv)
static void pch_can_config_rx_tx_buffers(struct pch_can_priv *priv)
{
int i;
- unsigned long flags;
-
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);

for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++) {
iowrite32(PCH_CMASK_RX_TX_GET,
@@ -527,7 +510,6 @@ static void pch_can_config_rx_tx_buffers(struct
pch_can_priv *priv)

pch_can_check_if_busy(&priv->regs->ifregs[1].creq, i);
}
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
}

static void pch_can_init(struct pch_can_priv *priv)
@@ -846,7 +828,6 @@ static int pch_can_rx_poll(struct napi_struct *napi,
int quota)
u32 int_stat;
int rcv_pkts = 0;
u32 reg_stat;
- unsigned long flags;

int_stat = pch_can_int_pending(priv);
if (!int_stat)
@@ -861,12 +842,10 @@ INT_STAT:
}

if (reg_stat & PCH_TX_OK) {
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
iowrite32(PCH_CMASK_RX_TX_GET,
&priv->regs->ifregs[1].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[1].creq,
ioread32(&priv->regs->intr));
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
pch_can_bit_clear(&priv->regs->stat, PCH_TX_OK);
}

@@ -880,22 +859,18 @@ INT_STAT:

MSG_OBJ:
if ((int_stat >= PCH_RX_OBJ_START) && (int_stat <= PCH_RX_OBJ_END)) {
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
rcv_pkts = pch_can_rx_normal(ndev, int_stat);
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
if (rcv_pkts < 0)
return 0;
} else if ((int_stat >= PCH_TX_OBJ_START) &&
(int_stat <= PCH_TX_OBJ_END)) {
/* Handle transmission interrupt */
can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_END - 1);
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
iowrite32(PCH_CMASK_RX_TX_GET | PCH_CMASK_CLRINTPND,
&priv->regs->ifregs[1].cmask);
dlc = ioread32(&priv->regs->ifregs[1].mcont) &
PCH_IF_MCONT_DLC;
pch_can_check_if_busy(&priv->regs->ifregs[1].creq, int_stat);
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
if (dlc > 8)
dlc = 8;
stats->tx_bytes += dlc;
@@ -1043,7 +1018,6 @@ static int pch_close(struct net_device *ndev)
static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
{
int i, j;
- unsigned long flags;
struct pch_can_priv *priv = netdev_priv(ndev);
struct can_frame *cf = (struct can_frame *)skb->data;
int tx_obj_no = 0;
@@ -1062,9 +1036,6 @@ static netdev_tx_t pch_xmit(struct sk_buff *skb,
struct net_device *ndev)
priv->tx_obj++;
}

- /* Attaining the lock. */
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-
/* Reading the Msg Obj from the Msg RAM to the Interface register. */
iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[1].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[1].creq, tx_obj_no);
@@ -1116,8 +1087,6 @@ static netdev_tx_t pch_xmit(struct sk_buff *skb,
struct net_device *ndev)

pch_can_check_if_busy(&priv->regs->ifregs[1].creq, tx_obj_no);

- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
-
return NETDEV_TX_OK;
}

--
1.6.0.6