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authorYury Georgievskiy <ygeorgie@gmail.com>2010-07-20 18:26:50 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2010-08-10 16:47:45 -0400
commit0ac8382e9cfdd723445692fc97aaa4643929750d (patch)
treee42c65488ea8d839c39441dce939d21ba6d60ae6 /drivers/serial
parent1b6331848b69d1ed165a6bdc75c4046d68767563 (diff)
serial: mcf: don't take spinlocks in already protected functions
Don't take the port spinlock in uart functions where the serial core already takes care of locking/unlocking them. The code would actually lock up on architectures where spinlocks are implemented. Also protect calling mcf_rx_chars/mcf_tx_chars in the interrupt handler by the port spinlock and use IRQ_RETVAL to return from isr. [akpm@linux-foundation.org: make irq-handler return value more explicit] Signed-off-by: Yury Georgievskiy <ygeorgie@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Acked-by: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/serial')
-rw-r--r--drivers/serial/mcf.c31
1 files changed, 13 insertions, 18 deletions
diff --git a/drivers/serial/mcf.c b/drivers/serial/mcf.c
index b5aaef965f24..3394b7cc1722 100644
--- a/drivers/serial/mcf.c
+++ b/drivers/serial/mcf.c
@@ -70,16 +70,14 @@ static unsigned int mcf_tx_empty(struct uart_port *port)
70static unsigned int mcf_get_mctrl(struct uart_port *port) 70static unsigned int mcf_get_mctrl(struct uart_port *port)
71{ 71{
72 struct mcf_uart *pp = container_of(port, struct mcf_uart, port); 72 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
73 unsigned long flags;
74 unsigned int sigs; 73 unsigned int sigs;
75 74
76 spin_lock_irqsave(&port->lock, flags);
77 sigs = (readb(port->membase + MCFUART_UIPR) & MCFUART_UIPR_CTS) ? 75 sigs = (readb(port->membase + MCFUART_UIPR) & MCFUART_UIPR_CTS) ?
78 0 : TIOCM_CTS; 76 0 : TIOCM_CTS;
79 sigs |= (pp->sigs & TIOCM_RTS); 77 sigs |= (pp->sigs & TIOCM_RTS);
80 sigs |= (mcf_getppdcd(port->line) ? TIOCM_CD : 0); 78 sigs |= (mcf_getppdcd(port->line) ? TIOCM_CD : 0);
81 sigs |= (mcf_getppdtr(port->line) ? TIOCM_DTR : 0); 79 sigs |= (mcf_getppdtr(port->line) ? TIOCM_DTR : 0);
82 spin_unlock_irqrestore(&port->lock, flags); 80
83 return sigs; 81 return sigs;
84} 82}
85 83
@@ -88,16 +86,13 @@ static unsigned int mcf_get_mctrl(struct uart_port *port)
88static void mcf_set_mctrl(struct uart_port *port, unsigned int sigs) 86static void mcf_set_mctrl(struct uart_port *port, unsigned int sigs)
89{ 87{
90 struct mcf_uart *pp = container_of(port, struct mcf_uart, port); 88 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
91 unsigned long flags;
92 89
93 spin_lock_irqsave(&port->lock, flags);
94 pp->sigs = sigs; 90 pp->sigs = sigs;
95 mcf_setppdtr(port->line, (sigs & TIOCM_DTR)); 91 mcf_setppdtr(port->line, (sigs & TIOCM_DTR));
96 if (sigs & TIOCM_RTS) 92 if (sigs & TIOCM_RTS)
97 writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1); 93 writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP1);
98 else 94 else
99 writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP0); 95 writeb(MCFUART_UOP_RTS, port->membase + MCFUART_UOP0);
100 spin_unlock_irqrestore(&port->lock, flags);
101} 96}
102 97
103/****************************************************************************/ 98/****************************************************************************/
@@ -105,12 +100,9 @@ static void mcf_set_mctrl(struct uart_port *port, unsigned int sigs)
105static void mcf_start_tx(struct uart_port *port) 100static void mcf_start_tx(struct uart_port *port)
106{ 101{
107 struct mcf_uart *pp = container_of(port, struct mcf_uart, port); 102 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
108 unsigned long flags;
109 103
110 spin_lock_irqsave(&port->lock, flags);
111 pp->imr |= MCFUART_UIR_TXREADY; 104 pp->imr |= MCFUART_UIR_TXREADY;
112 writeb(pp->imr, port->membase + MCFUART_UIMR); 105 writeb(pp->imr, port->membase + MCFUART_UIMR);
113 spin_unlock_irqrestore(&port->lock, flags);
114} 106}
115 107
116/****************************************************************************/ 108/****************************************************************************/
@@ -118,12 +110,9 @@ static void mcf_start_tx(struct uart_port *port)
118static void mcf_stop_tx(struct uart_port *port) 110static void mcf_stop_tx(struct uart_port *port)
119{ 111{
120 struct mcf_uart *pp = container_of(port, struct mcf_uart, port); 112 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
121 unsigned long flags;
122 113
123 spin_lock_irqsave(&port->lock, flags);
124 pp->imr &= ~MCFUART_UIR_TXREADY; 114 pp->imr &= ~MCFUART_UIR_TXREADY;
125 writeb(pp->imr, port->membase + MCFUART_UIMR); 115 writeb(pp->imr, port->membase + MCFUART_UIMR);
126 spin_unlock_irqrestore(&port->lock, flags);
127} 116}
128 117
129/****************************************************************************/ 118/****************************************************************************/
@@ -131,12 +120,9 @@ static void mcf_stop_tx(struct uart_port *port)
131static void mcf_stop_rx(struct uart_port *port) 120static void mcf_stop_rx(struct uart_port *port)
132{ 121{
133 struct mcf_uart *pp = container_of(port, struct mcf_uart, port); 122 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
134 unsigned long flags;
135 123
136 spin_lock_irqsave(&port->lock, flags);
137 pp->imr &= ~MCFUART_UIR_RXREADY; 124 pp->imr &= ~MCFUART_UIR_RXREADY;
138 writeb(pp->imr, port->membase + MCFUART_UIMR); 125 writeb(pp->imr, port->membase + MCFUART_UIMR);
139 spin_unlock_irqrestore(&port->lock, flags);
140} 126}
141 127
142/****************************************************************************/ 128/****************************************************************************/
@@ -366,13 +352,22 @@ static irqreturn_t mcf_interrupt(int irq, void *data)
366 struct uart_port *port = data; 352 struct uart_port *port = data;
367 struct mcf_uart *pp = container_of(port, struct mcf_uart, port); 353 struct mcf_uart *pp = container_of(port, struct mcf_uart, port);
368 unsigned int isr; 354 unsigned int isr;
355 irqreturn_t ret = IRQ_NONE;
369 356
370 isr = readb(port->membase + MCFUART_UISR) & pp->imr; 357 isr = readb(port->membase + MCFUART_UISR) & pp->imr;
371 if (isr & MCFUART_UIR_RXREADY) 358
359 spin_lock(&port->lock);
360 if (isr & MCFUART_UIR_RXREADY) {
372 mcf_rx_chars(pp); 361 mcf_rx_chars(pp);
373 if (isr & MCFUART_UIR_TXREADY) 362 ret = IRQ_HANDLED;
363 }
364 if (isr & MCFUART_UIR_TXREADY) {
374 mcf_tx_chars(pp); 365 mcf_tx_chars(pp);
375 return IRQ_HANDLED; 366 ret = IRQ_HANDLED;
367 }
368 spin_unlock(&port->lock);
369
370 return ret;
376} 371}
377 372
378/****************************************************************************/ 373/****************************************************************************/