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tty: moxa: rework the locking a bit 

Introduce a lock for moxafunc() to protect the cases where were get collisions
between two function requests at the same time.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Cox 2009-11-30 13:17:57 +00:00 committed by Greg Kroah-Hartman
parent f176178ba0
commit f5c5a36d27
1 changed files with 22 additions and 5 deletions
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27
drivers/char/moxa.c
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@ -248,9 +248,25 @@ static void moxa_wait_finish(void __iomem *ofsAddr)
static void moxafunc(void __iomem *ofsAddr, u16 cmd, u16 arg)
{
unsigned long flags;
spin_lock_irqsave(&moxafunc_lock, flags);
writew(arg, ofsAddr + FuncArg);
writew(cmd, ofsAddr + FuncCode);
moxa_wait_finish(ofsAddr);
spin_unlock_irqrestore(&moxafunc_lock, flags);
}
static int moxafuncret(void __iomem *ofsAddr, u16 cmd, u16 arg)
{
unsigned long flags;
u16 ret;
spin_lock_irqsave(&moxafunc_lock, flags);
writew(arg, ofsAddr + FuncArg);
writew(cmd, ofsAddr + FuncCode);
moxa_wait_finish(ofsAddr);
ret = readw(ofsAddr + FuncArg);
spin_unlock_irqrestore(&moxafunc_lock, flags);
return ret;
}
static void moxa_low_water_check(void __iomem *ofsAddr)
@ -417,6 +433,7 @@ static const struct tty_port_operations moxa_port_ops = {
static struct tty_driver *moxaDriver;
static DEFINE_TIMER(moxaTimer, moxa_poll, 0, 0);
static DEFINE_SPINLOCK(moxa_lock);
static DEFINE_SPINLOCK(moxafunc_lock);
/*
* HW init
@ -1823,10 +1840,12 @@ static int MoxaPortSetTermio(struct moxa_port *port, struct ktermios *termio,
baud = MoxaPortSetBaud(port, baud);
if (termio->c_iflag & (IXON | IXOFF | IXANY)) {
spin_lock_irq(&moxafunc_lock);
writeb(termio->c_cc[VSTART], ofsAddr + FuncArg);
writeb(termio->c_cc[VSTOP], ofsAddr + FuncArg1);
writeb(FC_SetXonXoff, ofsAddr + FuncCode);
moxa_wait_finish(ofsAddr);
spin_unlock_irqrestore(&moxafunc_lock);
}
return baud;
@ -1879,12 +1898,10 @@ static int MoxaPortLineStatus(struct moxa_port *port)
int val;
ofsAddr = port->tableAddr;
if (MOXA_IS_320(port->board)) {
moxafunc(ofsAddr, FC_LineStatus, 0);
val = readw(ofsAddr + FuncArg);
} else {
if (MOXA_IS_320(port->board))
val = moxafuncret(ofsAddr, FC_LineStatus, 0);
else
val = readw(ofsAddr + FlagStat) >> 4;
}
val &= 0x0B;
if (val & 8)
val |= 4;