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raspberrypi-kernel
提交 cfe7c09a 编写于 作者: J Jiri Slaby 提交者： Linus Torvalds
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[PATCH] Char: isicom, eliminate spinlock recursion 

Many spinlock recursion was in the isicom driver.  Eliminate it.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
上级 10f549fa
隐藏空白更改
内联 并排
Showing with 51 addition and 52 deletion
drivers/char/isicom.c
浏览文件 @ cfe7c09a
......@@ -230,6 +230,20 @@ static struct isi_port isi_ports[PORT_COUNT];
* it wants to talk.
*/
static inline int WaitTillCardIsFree(u16 base)
{
unsigned int count = 0;
unsigned int a = in_atomic(); /* do we run under spinlock? */
while (!(inw(base + 0xe) & 0x1) && count++ < 100)
if (a)
mdelay(1);
else
msleep(1);
return !(inw(base + 0xe) & 0x1);
}
static int lock_card(struct isi_board *card)
{
char retries;
......@@ -276,69 +290,71 @@ static void unlock_card(struct isi_board *card)
* ISI Card specific ops ...
*/
/* card->lock HAS to be held */
static void raise_dtr(struct isi_port *port)
{
struct isi_board *card = port->card;
unsigned long base = card->base;
u16 channel = port->channel;
if (!lock_card(card))
if (WaitTillCardIsFree(base))
return;
outw(0x8000 | (channel << card->shift_count) | 0x02, base);
outw(0x0504, base);
InterruptTheCard(base);
port->status |= ISI_DTR;
unlock_card(card);
}
/* card->lock HAS to be held */
static inline void drop_dtr(struct isi_port *port)
{
struct isi_board *card = port->card;
unsigned long base = card->base;
u16 channel = port->channel;
if (!lock_card(card))
if (WaitTillCardIsFree(base))
return;
outw(0x8000 | (channel << card->shift_count) | 0x02, base);
outw(0x0404, base);
InterruptTheCard(base);
port->status &= ~ISI_DTR;
unlock_card(card);
}
/* card->lock HAS to be held */
static inline void raise_rts(struct isi_port *port)
{
struct isi_board *card = port->card;
unsigned long base = card->base;
u16 channel = port->channel;
if (!lock_card(card))
if (WaitTillCardIsFree(base))
return;
outw(0x8000 | (channel << card->shift_count) | 0x02, base);
outw(0x0a04, base);
InterruptTheCard(base);
port->status |= ISI_RTS;
unlock_card(card);
}
/* card->lock HAS to be held */
static inline void drop_rts(struct isi_port *port)
{
struct isi_board *card = port->card;
unsigned long base = card->base;
u16 channel = port->channel;
if (!lock_card(card))
if (WaitTillCardIsFree(base))
return;
outw(0x8000 | (channel << card->shift_count) | 0x02, base);
outw(0x0804, base);
InterruptTheCard(base);
port->status &= ~ISI_RTS;
unlock_card(card);
}
/* card->lock MUST NOT be held */
static inline void raise_dtr_rts(struct isi_port *port)
{
struct isi_board *card = port->card;
......@@ -355,35 +371,20 @@ static inline void raise_dtr_rts(struct isi_port *port)
unlock_card(card);
}
/* card->lock HAS to be held */
static void drop_dtr_rts(struct isi_port *port)
{
struct isi_board *card = port->card;
unsigned long base = card->base;
u16 channel = port->channel;
if (!lock_card(card))
if (WaitTillCardIsFree(base))
return;
outw(0x8000 | (channel << card->shift_count) | 0x02, base);
outw(0x0c04, base);
InterruptTheCard(base);
port->status &= ~(ISI_RTS | ISI_DTR);
unlock_card(card);
}
static inline void kill_queue(struct isi_port *port, short queue)
{
struct isi_board *card = port->card;
unsigned long base = card->base;
u16 channel = port->channel;
if (!lock_card(card))
return;
outw(0x8000 | (channel << card->shift_count) | 0x02, base);
outw((queue << 8) | 0x06, base);
InterruptTheCard(base);
unlock_card(card);
}
/*
......@@ -744,7 +745,7 @@ static void isicom_config_port(struct isi_port *port)
else
raise_dtr(port);
if (lock_card(card)) {
if (WaitTillCardIsFree(base) == 0) {
outw(0x8000 | (channel << shift_count) |0x03, base);
outw(linuxb_to_isib[baud] << 8 | 0x03, base);
channel_setup = 0;
......@@ -772,7 +773,6 @@ static void isicom_config_port(struct isi_port *port)
}
outw(channel_setup, base);
InterruptTheCard(base);
unlock_card(card);
}
if (C_CLOCAL(tty))
port->flags &= ~ASYNC_CHECK_CD;
......@@ -791,12 +791,11 @@ static void isicom_config_port(struct isi_port *port)
if (I_IXOFF(tty))
flow_ctrl |= ISICOM_INITIATE_XONXOFF;
if (lock_card(card)) {
if (WaitTillCardIsFree(base) == 0) {
outw(0x8000 | (channel << shift_count) |0x04, base);
outw(flow_ctrl << 8 | 0x05, base);
outw((STOP_CHAR(tty)) << 8 | (START_CHAR(tty)), base);
InterruptTheCard(base);
unlock_card(card);
}
/* rx enabled -> enable port for rx on the card */
......@@ -821,10 +820,9 @@ static inline void isicom_setup_board(struct isi_board *bp)
}
port = bp->ports;
bp->status |= BOARD_ACTIVE;
spin_unlock_irqrestore(&bp->card_lock, flags);
for (channel = 0; channel < bp->port_count; channel++, port++)
drop_dtr_rts(port);
return;
spin_unlock_irqrestore(&bp->card_lock, flags);
}
static int isicom_setup_port(struct isi_port *port)
......@@ -857,7 +855,12 @@ static int isicom_setup_port(struct isi_port *port)
port->xmit_cnt = port->xmit_head = port->xmit_tail = 0;
/* discard any residual data */
kill_queue(port, ISICOM_KILLTX | ISICOM_KILLRX);
if (WaitTillCardIsFree(card->base) == 0) {
outw(0x8000 | (port->channel << card->shift_count) | 0x02,
card->base);
outw(((ISICOM_KILLTX | ISICOM_KILLRX) << 8) | 0x06, card->base);
InterruptTheCard(card->base);
}
isicom_config_port(port);
port->flags |= ASYNC_INITIALIZED;
......@@ -983,28 +986,22 @@ static int isicom_open(struct tty_struct *tty, struct file *filp)
static inline void isicom_shutdown_board(struct isi_board *bp)
{
unsigned long flags;
spin_lock_irqsave(&bp->card_lock, flags);
if (bp->status & BOARD_ACTIVE) {
bp->status &= ~BOARD_ACTIVE;
}
spin_unlock_irqrestore(&bp->card_lock, flags);
}
/* card->lock HAS to be held */
static void isicom_shutdown_port(struct isi_port *port)
{
struct isi_board *card = port->card;
struct tty_struct *tty;
unsigned long flags;
tty = port->tty;
spin_lock_irqsave(&card->card_lock, flags);
if (!(port->flags & ASYNC_INITIALIZED)) {
spin_unlock_irqrestore(&card->card_lock, flags);
if (!(port->flags & ASYNC_INITIALIZED))
return;
}
if (port->xmit_buf) {
free_page((unsigned long) port->xmit_buf);
port->xmit_buf = NULL;
......@@ -1012,7 +1009,6 @@ static void isicom_shutdown_port(struct isi_port *port)
port->flags &= ~ASYNC_INITIALIZED;
/* 3rd October 2000 : Vinayak P Risbud */
port->tty = NULL;
spin_unlock_irqrestore(&card->card_lock, flags);
/*Fix done by Anil .S on 30-04-2001
remote login through isi port has dtr toggle problem
......@@ -1258,10 +1254,12 @@ static int isicom_tiocmset(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear)
{
struct isi_port *port = tty->driver_data;
unsigned long flags;
if (isicom_paranoia_check(port, tty->name, "isicom_ioctl"))
return -ENODEV;
spin_lock_irqsave(&port->card->card_lock, flags);
if (set & TIOCM_RTS)
raise_rts(port);
if (set & TIOCM_DTR)
......@@ -1271,6 +1269,7 @@ static int isicom_tiocmset(struct tty_struct *tty, struct file *file,
drop_rts(port);
if (clear & TIOCM_DTR)
drop_dtr(port);
spin_unlock_irqrestore(&port->card->card_lock, flags);
return 0;
}
......@@ -1303,7 +1302,10 @@ static int isicom_set_serial_info(struct isi_port *port,
(newinfo.flags & ASYNC_FLAGS));
}
if (reconfig_port) {
unsigned long flags;
spin_lock_irqsave(&port->card->card_lock, flags);
isicom_config_port(port);
spin_unlock_irqrestore(&port->card->card_lock, flags);
}
return 0;
}
......@@ -1384,6 +1386,7 @@ static void isicom_set_termios(struct tty_struct *tty,
struct ktermios *old_termios)
{
struct isi_port *port = tty->driver_data;
unsigned long flags;
if (isicom_paranoia_check(port, tty->name, "isicom_set_termios"))
return;
......@@ -1392,7 +1395,9 @@ static void isicom_set_termios(struct tty_struct *tty,
tty->termios->c_iflag == old_termios->c_iflag)
return;
spin_lock_irqsave(&port->card->card_lock, flags);
isicom_config_port(port);
spin_unlock_irqrestore(&port->card->card_lock, flags);
if ((old_termios->c_cflag & CRTSCTS) &&
!(tty->termios->c_cflag & CRTSCTS)) {
......@@ -1469,11 +1474,15 @@ static void do_isicom_hangup(struct work_struct *work)
static void isicom_hangup(struct tty_struct *tty)
{
struct isi_port *port = tty->driver_data;
unsigned long flags;
if (isicom_paranoia_check(port, tty->name, "isicom_hangup"))
return;
spin_lock_irqsave(&port->card->card_lock, flags);
isicom_shutdown_port(port);
spin_unlock_irqrestore(&port->card->card_lock, flags);
port->count = 0;
port->flags &= ~ASYNC_NORMAL_ACTIVE;
port->tty = NULL;
......@@ -1578,16 +1587,6 @@ static int __devinit reset_card(struct pci_dev *pdev,
return retval;
}
static inline int WaitTillCardIsFree(u16 base)
{
unsigned long count = 0;
while (!(inw(base + 0xe) & 0x1) && count++ < 100)
msleep(5);
return !(inw(base + 0xe) & 0x1);
}
static int __devinit load_firmware(struct pci_dev *pdev,
const unsigned int index, const unsigned int signature)
{
......
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