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dz: fix locking issues

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The ->start_tx(), ->stop_tx() and ->stop_rx() backends are called with the
port's lock already taken.  Remove locking from within them and wrap around
calls as necessary.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Maciej W. Rozycki
2008-02-07 00:15:11 -08:00
committed by Linus Torvalds
parent 6d83c067eb
commit 43d46ab1cd
1 changed files with 12 additions and 11 deletions
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23
drivers/serial/dz.c
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@@ -108,37 +108,28 @@ static void dz_stop_tx(struct uart_port *uport)
{ {
struct dz_port *dport = (struct dz_port *)uport; struct dz_port *dport = (struct dz_port *)uport;
unsigned short tmp, mask = 1 << dport->port.line; unsigned short tmp, mask = 1 << dport->port.line;
unsigned long flags;
spin_lock_irqsave(&dport->port.lock, flags);
tmp = dz_in(dport, DZ_TCR); /* read the TX flag */ tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
tmp &= ~mask; /* clear the TX flag */ tmp &= ~mask; /* clear the TX flag */
dz_out(dport, DZ_TCR, tmp); dz_out(dport, DZ_TCR, tmp);
spin_unlock_irqrestore(&dport->port.lock, flags);
} }
static void dz_start_tx(struct uart_port *uport) static void dz_start_tx(struct uart_port *uport)
{ {
struct dz_port *dport = (struct dz_port *)uport; struct dz_port *dport = (struct dz_port *)uport;
unsigned short tmp, mask = 1 << dport->port.line; unsigned short tmp, mask = 1 << dport->port.line;
unsigned long flags;
spin_lock_irqsave(&dport->port.lock, flags);
tmp = dz_in(dport, DZ_TCR); /* read the TX flag */ tmp = dz_in(dport, DZ_TCR); /* read the TX flag */
tmp |= mask; /* set the TX flag */ tmp |= mask; /* set the TX flag */
dz_out(dport, DZ_TCR, tmp); dz_out(dport, DZ_TCR, tmp);
spin_unlock_irqrestore(&dport->port.lock, flags);
} }
static void dz_stop_rx(struct uart_port *uport) static void dz_stop_rx(struct uart_port *uport)
{ {
struct dz_port *dport = (struct dz_port *)uport; struct dz_port *dport = (struct dz_port *)uport;
unsigned long flags;
spin_lock_irqsave(&dport->port.lock, flags);
dport->cflag &= ~DZ_CREAD; dport->cflag &= ~DZ_CREAD;
dz_out(dport, DZ_LPR, dport->cflag | dport->port.line); dz_out(dport, DZ_LPR, dport->cflag | dport->port.line);
spin_unlock_irqrestore(&dport->port.lock, flags);
} }
static void dz_enable_ms(struct uart_port *port) static void dz_enable_ms(struct uart_port *port)
@@ -268,7 +259,9 @@ static inline void dz_transmit_chars(struct dz_port *dport_in)
} }
/* If nothing to do or stopped or hardware stopped. */ /* If nothing to do or stopped or hardware stopped. */
if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) { if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
spin_lock(&dport->port.lock);
dz_stop_tx(&dport->port); dz_stop_tx(&dport->port);
spin_unlock(&dport->port.lock);
return; return;
} }
@@ -285,8 +278,11 @@ static inline void dz_transmit_chars(struct dz_port *dport_in)
uart_write_wakeup(&dport->port); uart_write_wakeup(&dport->port);
/* Are we are done. */ /* Are we are done. */
if (uart_circ_empty(xmit)) if (uart_circ_empty(xmit)) {
spin_lock(&dport->port.lock);
dz_stop_tx(&dport->port); dz_stop_tx(&dport->port);
spin_unlock(&dport->port.lock);
}
} }
/* /*
@@ -417,7 +413,12 @@ static int dz_startup(struct uart_port *uport)
*/ */
static void dz_shutdown(struct uart_port *uport) static void dz_shutdown(struct uart_port *uport)
{ {
dz_stop_tx(uport); struct dz_port *dport = (struct dz_port *)uport;
unsigned long flags;
spin_lock_irqsave(&dport->port.lock, flags);
dz_stop_tx(&dport->port);
spin_unlock_irqrestore(&dport->port.lock, flags);
} }
/* /*