The patch titled
Char: isicom, eliminate spinlock recursion
has been added to the -mm tree. Its filename is
char-isicom-eliminate-spinlock-recursion.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Char: isicom, eliminate spinlock recursion
From: Jiri Slaby <jirislaby@xxxxxxxxx>
Many spinlock recursion was in the isicom driver. Eliminate it.
Signed-off-by: Jiri Slaby <jirislaby@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
drivers/char/isicom.c | 103 +++++++++++++++++++---------------------
1 file changed, 51 insertions(+), 52 deletions(-)
diff -puN drivers/char/isicom.c~char-isicom-eliminate-spinlock-recursion drivers/char/isicom.c
--- a/drivers/char/isicom.c~char-isicom-eliminate-spinlock-recursion
+++ a/drivers/char/isicom.c
@@ -230,6 +230,20 @@ static struct isi_port isi_ports[PORT_C
* 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
* 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
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 is
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 is
}
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 is
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(st
}
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->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
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
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_st
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_st
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
(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 tt
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 tt
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
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 @@ end:
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)
{
_
Patches currently in -mm which might be from jirislaby@xxxxxxxxx are
char-mxser-fix-oops-when-removing-opened.patch
char-isicom-eliminate-spinlock-recursion.patch
git-input.patch
char-tty-delete-wake_up_interruptible-after-tty_wakeup.patch
char-isicom-remove-tty_hangwakeup-bottomhalves.patch
mxser-remove-ambiguous-redefinition-of-init_work.patch
make-drivers-char-mxser_newcmxser_hangup-static.patch
char-isicom-fix-locking-in-isr.patch
char-isicom-augment-card_reset.patch
char-isicom-check-card-state-in-isr.patch
char-isicom-support-higher-rates.patch
char-isicom-correct-probing-removing.patch
char-tty_wakeup-cleanup.patch
char-mxser_new-mark-init-functions.patch
char-mxser_new-remove-useless-spinlock.patch
shrink_slab-handle-bad-shrinkers.patch
-
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