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Subject[PATCH] TTY: synclink: Convert + to | for bit operations
From
Date
Dan Carpenter noticed a missing set of parentheses
around a multiple field addition.

https://lkml.org/lkml/2013/1/27/166

His original commit message:

There is a kind of precedence problem here, but it doesn't affect how
the code works because ->serial_signals is unsigned char. We want to
clear two flags here.

#define SerialSignal_RTS 0x20 /* Request to Send */
#define SerialSignal_DTR 0x80 /* Data Terminal Ready */

Without the parenthesis then it does:

info->serial_signals &= 0x5f;

With the parenthesis it does:

info->serial_signals &= 0xffffff5f;

info->serial_signals is an unsigned char so the two statements are
equivalent, but it's cleaner to add the parenthesis. In other dtr_rts()
functions the parenthesis are there so this makes it more consistent.

Other changes:

Convert all + uses to | for these bit operations.

Reorder the multiple fields for consistency.
Update the comments too.

cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Joe Perches <joe@perches.com>
---
drivers/char/pcmcia/synclink_cs.c | 26 ++++++++++++-------------
drivers/tty/synclink.c | 26 ++++++++++++-------------
drivers/tty/synclink_gt.c | 26 ++++++++++++-------------
drivers/tty/synclinkmp.c | 40 +++++++++++++++++++--------------------
4 files changed, 59 insertions(+), 59 deletions(-)

diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c
index 34e52ed..d0c9852 100644
--- a/drivers/char/pcmcia/synclink_cs.c
+++ b/drivers/char/pcmcia/synclink_cs.c
@@ -1343,7 +1343,7 @@ static void shutdown(MGSLPC_INFO * info, struct tty_struct *tty)
reset_device(info);

if (!tty || tty->termios.c_cflag & HUPCL) {
- info->serial_signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
set_signals(info);
}

@@ -1405,12 +1405,12 @@ static void mgslpc_change_params(MGSLPC_INFO *info, struct tty_struct *tty)

cflag = tty->termios.c_cflag;

- /* if B0 rate (hangup) specified then negate DTR and RTS */
- /* otherwise assert DTR and RTS */
+ /* if B0 rate (hangup) specified then negate RTS and DTR */
+ /* otherwise assert RTS and DTR */
if (cflag & CBAUD)
- info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+ info->serial_signals |= SerialSignal_RTS | SerialSignal_DTR;
else
- info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);

/* byte size and parity */

@@ -2301,7 +2301,7 @@ static void mgslpc_set_termios(struct tty_struct *tty, struct ktermios *old_term
/* Handle transition to B0 status */
if (old_termios->c_cflag & CBAUD &&
!(tty->termios.c_cflag & CBAUD)) {
- info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
spin_lock_irqsave(&info->lock,flags);
set_signals(info);
spin_unlock_irqrestore(&info->lock,flags);
@@ -2464,9 +2464,9 @@ static void dtr_rts(struct tty_port *port, int onoff)

spin_lock_irqsave(&info->lock,flags);
if (onoff)
- info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+ info->serial_signals |= SerialSignal_RTS | SerialSignal_DTR;
else
- info->serial_signals &= ~SerialSignal_RTS + SerialSignal_DTR;
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
set_signals(info);
spin_unlock_irqrestore(&info->lock,flags);
}
@@ -3575,8 +3575,8 @@ static void get_signals(MGSLPC_INFO *info)
{
unsigned char status = 0;

- /* preserve DTR and RTS */
- info->serial_signals &= SerialSignal_DTR + SerialSignal_RTS;
+ /* preserve RTS and DTR */
+ info->serial_signals &= SerialSignal_RTS | SerialSignal_DTR;

if (read_reg(info, CHB + VSTR) & BIT7)
info->serial_signals |= SerialSignal_DCD;
@@ -3590,7 +3590,7 @@ static void get_signals(MGSLPC_INFO *info)
info->serial_signals |= SerialSignal_DSR;
}

-/* Set the state of DTR and RTS based on contents of
+/* Set the state of RTS and DTR based on contents of
* serial_signals member of device extension.
*/
static void set_signals(MGSLPC_INFO *info)
@@ -4009,8 +4009,8 @@ static int hdlcdev_open(struct net_device *dev)
spin_unlock_irqrestore(&info->netlock, flags);
return rc;
}
- /* assert DTR and RTS, apply hardware settings */
- info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+ /* assert RTS and DTR, apply hardware settings */
+ info->serial_signals |= SerialSignal_RTS | SerialSignal_DTR;
mgslpc_program_hw(info, tty);
tty_kref_put(tty);

diff --git a/drivers/tty/synclink.c b/drivers/tty/synclink.c
index 555fdc0..8983276 100644
--- a/drivers/tty/synclink.c
+++ b/drivers/tty/synclink.c
@@ -1850,7 +1850,7 @@ static void shutdown(struct mgsl_struct * info)
usc_OutReg(info, PCR, (u16)((usc_InReg(info, PCR) | BIT13) | BIT12));

if (!info->port.tty || info->port.tty->termios.c_cflag & HUPCL) {
- info->serial_signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
usc_set_serial_signals(info);
}

@@ -1915,12 +1915,12 @@ static void mgsl_change_params(struct mgsl_struct *info)

cflag = info->port.tty->termios.c_cflag;

- /* if B0 rate (hangup) specified then negate DTR and RTS */
- /* otherwise assert DTR and RTS */
+ /* if B0 rate (hangup) specified then negate RTS and DTR */
+ /* otherwise assert RTS and DTR */
if (cflag & CBAUD)
- info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+ info->serial_signals |= SerialSignal_RTS | SerialSignal_DTR;
else
- info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);

/* byte size and parity */

@@ -3044,7 +3044,7 @@ static void mgsl_set_termios(struct tty_struct *tty, struct ktermios *old_termio
/* Handle transition to B0 status */
if (old_termios->c_cflag & CBAUD &&
!(tty->termios.c_cflag & CBAUD)) {
- info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
spin_lock_irqsave(&info->irq_spinlock,flags);
usc_set_serial_signals(info);
spin_unlock_irqrestore(&info->irq_spinlock,flags);
@@ -3243,9 +3243,9 @@ static void dtr_rts(struct tty_port *port, int on)

spin_lock_irqsave(&info->irq_spinlock,flags);
if (on)
- info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+ info->serial_signals |= SerialSignal_RTS | SerialSignal_DTR;
else
- info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
usc_set_serial_signals(info);
spin_unlock_irqrestore(&info->irq_spinlock,flags);
}
@@ -6239,8 +6239,8 @@ static void usc_get_serial_signals( struct mgsl_struct *info )
{
u16 status;

- /* clear all serial signals except DTR and RTS */
- info->serial_signals &= SerialSignal_DTR + SerialSignal_RTS;
+ /* clear all serial signals except RTS and DTR */
+ info->serial_signals &= SerialSignal_RTS | SerialSignal_DTR;

/* Read the Misc Interrupt status Register (MISR) to get */
/* the V24 status signals. */
@@ -6265,7 +6265,7 @@ static void usc_get_serial_signals( struct mgsl_struct *info )

/* usc_set_serial_signals()
*
- * Set the state of DTR and RTS based on contents of
+ * Set the state of RTS and DTR based on contents of
* serial_signals member of device extension.
*
* Arguments: info pointer to device instance data
@@ -7779,8 +7779,8 @@ static int hdlcdev_open(struct net_device *dev)
return rc;
}

- /* assert DTR and RTS, apply hardware settings */
- info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+ /* assert RTS and DTR, apply hardware settings */
+ info->serial_signals |= SerialSignal_RTS | SerialSignal_DTR;
mgsl_program_hw(info);

/* enable network layer transmit */
diff --git a/drivers/tty/synclink_gt.c b/drivers/tty/synclink_gt.c
index ac8599a..aa9eece 100644
--- a/drivers/tty/synclink_gt.c
+++ b/drivers/tty/synclink_gt.c
@@ -785,7 +785,7 @@ static void set_termios(struct tty_struct *tty, struct ktermios *old_termios)
/* Handle transition to B0 status */
if (old_termios->c_cflag & CBAUD &&
!(tty->termios.c_cflag & CBAUD)) {
- info->signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
spin_lock_irqsave(&info->lock,flags);
set_signals(info);
spin_unlock_irqrestore(&info->lock,flags);
@@ -1560,8 +1560,8 @@ static int hdlcdev_open(struct net_device *dev)
return rc;
}

- /* assert DTR and RTS, apply hardware settings */
- info->signals |= SerialSignal_RTS + SerialSignal_DTR;
+ /* assert RTS and DTR, apply hardware settings */
+ info->signals |= SerialSignal_RTS | SerialSignal_DTR;
program_hw(info);

/* enable network layer transmit */
@@ -2488,7 +2488,7 @@ static void shutdown(struct slgt_info *info)
slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);

if (!info->port.tty || info->port.tty->termios.c_cflag & HUPCL) {
- info->signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
+ info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
set_signals(info);
}

@@ -2548,12 +2548,12 @@ static void change_params(struct slgt_info *info)

cflag = info->port.tty->termios.c_cflag;

- /* if B0 rate (hangup) specified then negate DTR and RTS */
- /* otherwise assert DTR and RTS */
+ /* if B0 rate (hangup) specified then negate RTS and DTR */
+ /* otherwise assert RTS and DTR */
if (cflag & CBAUD)
- info->signals |= SerialSignal_RTS + SerialSignal_DTR;
+ info->signals |= SerialSignal_RTS | SerialSignal_DTR;
else
- info->signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);

/* byte size and parity */

@@ -3256,9 +3256,9 @@ static void dtr_rts(struct tty_port *port, int on)

spin_lock_irqsave(&info->lock,flags);
if (on)
- info->signals |= SerialSignal_RTS + SerialSignal_DTR;
+ info->signals |= SerialSignal_RTS | SerialSignal_DTR;
else
- info->signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
set_signals(info);
spin_unlock_irqrestore(&info->lock,flags);
}
@@ -4119,7 +4119,7 @@ static void reset_port(struct slgt_info *info)
tx_stop(info);
rx_stop(info);

- info->signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
+ info->signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
set_signals(info);

slgt_irq_off(info, IRQ_ALL | IRQ_MASTER);
@@ -4546,8 +4546,8 @@ static void get_signals(struct slgt_info *info)
{
unsigned short status = rd_reg16(info, SSR);

- /* clear all serial signals except DTR and RTS */
- info->signals &= SerialSignal_DTR + SerialSignal_RTS;
+ /* clear all serial signals except RTS and DTR */
+ info->signals &= SerialSignal_RTS | SerialSignal_DTR;

if (status & BIT3)
info->signals |= SerialSignal_DSR;
diff --git a/drivers/tty/synclinkmp.c b/drivers/tty/synclinkmp.c
index 5454025..6d5780c 100644
--- a/drivers/tty/synclinkmp.c
+++ b/drivers/tty/synclinkmp.c
@@ -882,7 +882,7 @@ static void set_termios(struct tty_struct *tty, struct ktermios *old_termios)
/* Handle transition to B0 status */
if (old_termios->c_cflag & CBAUD &&
!(tty->termios.c_cflag & CBAUD)) {
- info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
spin_lock_irqsave(&info->lock,flags);
set_signals(info);
spin_unlock_irqrestore(&info->lock,flags);
@@ -1676,8 +1676,8 @@ static int hdlcdev_open(struct net_device *dev)
return rc;
}

- /* assert DTR and RTS, apply hardware settings */
- info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+ /* assert RTS and DTR, apply hardware settings */
+ info->serial_signals |= SerialSignal_RTS | SerialSignal_DTR;
program_hw(info);

/* enable network layer transmit */
@@ -2706,7 +2706,7 @@ static void shutdown(SLMP_INFO * info)
reset_port(info);

if (!info->port.tty || info->port.tty->termios.c_cflag & HUPCL) {
- info->serial_signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
set_signals(info);
}

@@ -2768,12 +2768,12 @@ static void change_params(SLMP_INFO *info)

cflag = info->port.tty->termios.c_cflag;

- /* if B0 rate (hangup) specified then negate DTR and RTS */
- /* otherwise assert DTR and RTS */
+ /* if B0 rate (hangup) specified then negate RTS and DTR */
+ /* otherwise assert RTS and DTR */
if (cflag & CBAUD)
- info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+ info->serial_signals |= SerialSignal_RTS | SerialSignal_DTR;
else
- info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);

/* byte size and parity */

@@ -3212,12 +3212,12 @@ static int tiocmget(struct tty_struct *tty)
get_signals(info);
spin_unlock_irqrestore(&info->lock,flags);

- result = ((info->serial_signals & SerialSignal_RTS) ? TIOCM_RTS:0) +
- ((info->serial_signals & SerialSignal_DTR) ? TIOCM_DTR:0) +
- ((info->serial_signals & SerialSignal_DCD) ? TIOCM_CAR:0) +
- ((info->serial_signals & SerialSignal_RI) ? TIOCM_RNG:0) +
- ((info->serial_signals & SerialSignal_DSR) ? TIOCM_DSR:0) +
- ((info->serial_signals & SerialSignal_CTS) ? TIOCM_CTS:0);
+ result = ((info->serial_signals & SerialSignal_RTS) ? TIOCM_RTS : 0) |
+ ((info->serial_signals & SerialSignal_DTR) ? TIOCM_DTR : 0) |
+ ((info->serial_signals & SerialSignal_DCD) ? TIOCM_CAR : 0) |
+ ((info->serial_signals & SerialSignal_RI) ? TIOCM_RNG : 0) |
+ ((info->serial_signals & SerialSignal_DSR) ? TIOCM_DSR : 0) |
+ ((info->serial_signals & SerialSignal_CTS) ? TIOCM_CTS : 0);

if (debug_level >= DEBUG_LEVEL_INFO)
printk("%s(%d):%s tiocmget() value=%08X\n",
@@ -3272,9 +3272,9 @@ static void dtr_rts(struct tty_port *port, int on)

spin_lock_irqsave(&info->lock,flags);
if (on)
- info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;
+ info->serial_signals |= SerialSignal_RTS | SerialSignal_DTR;
else
- info->serial_signals &= ~(SerialSignal_RTS + SerialSignal_DTR);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
set_signals(info);
spin_unlock_irqrestore(&info->lock,flags);
}
@@ -4354,7 +4354,7 @@ static void reset_port(SLMP_INFO *info)
tx_stop(info);
rx_stop(info);

- info->serial_signals &= ~(SerialSignal_DTR + SerialSignal_RTS);
+ info->serial_signals &= ~(SerialSignal_RTS | SerialSignal_DTR);
set_signals(info);

/* disable all port interrupts */
@@ -4750,8 +4750,8 @@ static void get_signals(SLMP_INFO *info)
u16 gpstatus = read_status_reg(info);
u16 testbit;

- /* clear all serial signals except DTR and RTS */
- info->serial_signals &= SerialSignal_DTR + SerialSignal_RTS;
+ /* clear all serial signals except RTS and DTR */
+ info->serial_signals &= SerialSignal_RTS | SerialSignal_DTR;

/* set serial signal bits to reflect MISR */

@@ -4770,7 +4770,7 @@ static void get_signals(SLMP_INFO *info)
info->serial_signals |= SerialSignal_DSR;
}

-/* Set the state of DTR and RTS based on contents of
+/* Set the state of RTS and DTR based on contents of
* serial_signals member of device context.
*/
static void set_signals(SLMP_INFO *info)



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