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authorJiri Slaby <jirislaby@gmail.com>2007-10-18 03:06:20 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-18 14:37:26 -0700
commitebafeeff0fea029099e9952f233e0794106897a6 (patch)
tree50bc3ca7f9d4c7153c3e98bda28199dcc6eff948 /drivers/char
parentc43422053bea7a5ce09f18d0c50a606fe1a549f4 (diff)
downloadblackbird-op-linux-ebafeeff0fea029099e9952f233e0794106897a6.tar.gz
blackbird-op-linux-ebafeeff0fea029099e9952f233e0794106897a6.zip
Char: cyclades, remove bottom half processing
The work done in bottom half doesn't cost much cpu time (e.g. tty_hangup itself schedules its own bottom half), it's possible to do the work in isr directly and save hence some .text. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Paul Fulghum <paulkf@microgate.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/cyclades.c111
1 files changed, 20 insertions, 91 deletions
diff --git a/drivers/char/cyclades.c b/drivers/char/cyclades.c
index 9e0adfe27c12..817fef3071af 100644
--- a/drivers/char/cyclades.c
+++ b/drivers/char/cyclades.c
@@ -897,71 +897,6 @@ static inline int serial_paranoia_check(struct cyclades_port *info,
return 0;
} /* serial_paranoia_check */
-/*
- * This routine is used by the interrupt handler to schedule
- * processing in the software interrupt portion of the driver
- * (also known as the "bottom half"). This can be called any
- * number of times for any channel without harm.
- */
-static inline void cy_sched_event(struct cyclades_port *info, int event)
-{
- info->event |= 1 << event; /* remember what kind of event and who */
- schedule_work(&info->tqueue);
-} /* cy_sched_event */
-
-/*
- * This routine is used to handle the "bottom half" processing for the
- * serial driver, known also the "software interrupt" processing.
- * This processing is done at the kernel interrupt level, after the
- * cy#/_interrupt() has returned, BUT WITH INTERRUPTS TURNED ON. This
- * is where time-consuming activities which can not be done in the
- * interrupt driver proper are done; the interrupt driver schedules
- * them using cy_sched_event(), and they get done here.
- *
- * This is done through one level of indirection--the task queue.
- * When a hardware interrupt service routine wants service by the
- * driver's bottom half, it enqueues the appropriate tq_struct (one
- * per port) to the keventd work queue and sets a request flag
- * that the work queue be processed.
- *
- * Although this may seem unwieldy, it gives the system a way to
- * pass an argument (in this case the pointer to the cyclades_port
- * structure) to the bottom half of the driver. Previous kernels
- * had to poll every port to see if that port needed servicing.
- */
-static void
-do_softint(struct work_struct *work)
-{
- struct cyclades_port *info =
- container_of(work, struct cyclades_port, tqueue);
- struct tty_struct *tty;
-
- tty = info->tty;
- if (!tty)
- return;
-
- if (test_and_clear_bit(Cy_EVENT_HANGUP, &info->event)) {
- tty_hangup(info->tty);
- wake_up_interruptible(&info->open_wait);
- info->flags &= ~ASYNC_NORMAL_ACTIVE;
- }
- if (test_and_clear_bit(Cy_EVENT_OPEN_WAKEUP, &info->event))
- wake_up_interruptible(&info->open_wait);
-#ifdef CONFIG_CYZ_INTR
- if (test_and_clear_bit(Cy_EVENT_Z_RX_FULL, &info->event) &&
- !timer_pending(&cyz_rx_full_timer[info->line]))
- mod_timer(&cyz_rx_full_timer[info->line], jiffies + 1);
-#endif
- if (test_and_clear_bit(Cy_EVENT_DELTA_WAKEUP, &info->event))
- wake_up_interruptible(&info->delta_msr_wait);
- tty_wakeup(tty);
-#ifdef Z_WAKE
- if (test_and_clear_bit(Cy_EVENT_SHUTDOWN_WAKEUP, &info->event))
- complete(&info->shutdown_wait);
-#endif
-} /* do_softint */
-
-
/***********************************************************/
/********* Start of block of Cyclom-Y specific code ********/
@@ -1243,7 +1178,7 @@ static void cyy_intr_chip(struct cyclades_card *cinfo, int chip,
cy_writeb(base_addr + (CySRER << index),
readb(base_addr + (CySRER << index)) &
~CyTxRdy);
- goto txdone;
+ goto txend;
}
/* load the on-chip space for outbound data */
@@ -1334,9 +1269,7 @@ static void cyy_intr_chip(struct cyclades_card *cinfo, int chip,
}
txdone:
- if (info->xmit_cnt < WAKEUP_CHARS) {
- cy_sched_event(info, Cy_EVENT_WRITE_WAKEUP);
- }
+ tty_wakeup(info->tty);
txend:
/* end of service */
cy_writeb(base_addr + (CyTIR << index), (save_xir & 0x3f));
@@ -1369,17 +1302,16 @@ txend:
if (mdm_change & CyRI)
info->icount.rng++;
- cy_sched_event(info, Cy_EVENT_DELTA_WAKEUP);
+ wake_up_interruptible(&info->delta_msr_wait);
}
if ((mdm_change & CyDCD) &&
(info->flags & ASYNC_CHECK_CD)) {
- if (mdm_status & CyDCD) {
- cy_sched_event(info,
- Cy_EVENT_OPEN_WAKEUP);
- } else {
- cy_sched_event(info, Cy_EVENT_HANGUP);
+ if (!(mdm_status & CyDCD)) {
+ tty_hangup(info->tty);
+ info->flags &= ~ASYNC_NORMAL_ACTIVE;
}
+ wake_up_interruptible(&info->open_wait);
}
if ((mdm_change & CyCTS) &&
(info->flags & ASYNC_CTS_FLOW)) {
@@ -1394,8 +1326,7 @@ txend:
(CySRER <<
index))|
CyTxRdy);
- cy_sched_event(info,
- Cy_EVENT_WRITE_WAKEUP);
+ tty_wakeup(info->tty);
}
} else {
if (!(mdm_status & CyCTS)) {
@@ -1633,9 +1564,11 @@ cyz_handle_rx(struct cyclades_port *info, struct CH_CTRL __iomem *ch_ctrl,
char_count = rx_put - rx_get;
else
char_count = rx_put - rx_get + rx_bufsize;
- if (char_count >= (int)readl(&buf_ctrl->rx_threshold)) {
- cy_sched_event(info, Cy_EVENT_Z_RX_FULL);
- }
+ if (char_count >= (int)readl(&buf_ctrl->rx_threshold) &&
+ !timer_pending(&cyz_rx_full_timer[
+ info->line]))
+ mod_timer(&cyz_rx_full_timer[info->line],
+ jiffies + 1);
#endif
info->idle_stats.recv_idle = jiffies;
tty_schedule_flip(tty);
@@ -1717,9 +1650,7 @@ cyz_handle_tx(struct cyclades_port *info, struct CH_CTRL __iomem *ch_ctrl,
}
#endif
ztxdone:
- if (info->xmit_cnt < WAKEUP_CHARS) {
- cy_sched_event(info, Cy_EVENT_WRITE_WAKEUP);
- }
+ tty_wakeup(tty);
/* Update tx_put */
cy_writel(&buf_ctrl->tx_put, tx_put);
}
@@ -1781,10 +1712,11 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
if ((fw_ver > 241 ? ((u_long) param) :
readl(&ch_ctrl->rs_status)) &
C_RS_DCD) {
- cy_sched_event(info,
- Cy_EVENT_OPEN_WAKEUP);
+ wake_up_interruptible(&info->open_wait);
} else {
- cy_sched_event(info, Cy_EVENT_HANGUP);
+ tty_hangup(info->tty);
+ wake_up_interruptible(&info->open_wait);
+ info->flags &= ~ASYNC_NORMAL_ACTIVE;
}
}
break;
@@ -1802,7 +1734,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
break;
#ifdef Z_WAKE
case C_CM_IOCTLW:
- cy_sched_event(info, Cy_EVENT_SHUTDOWN_WAKEUP);
+ complete(&info->shutdown_wait);
break;
#endif
#ifdef CONFIG_CYZ_INTR
@@ -1834,7 +1766,7 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
break;
}
if (delta_count)
- cy_sched_event(info, Cy_EVENT_DELTA_WAKEUP);
+ wake_up_interruptible(&info->delta_msr_wait);
if (special_count)
tty_schedule_flip(tty);
}
@@ -2812,7 +2744,6 @@ static void cy_close(struct tty_struct *tty, struct file *filp)
spin_lock_irqsave(&card->card_lock, flags);
tty->closing = 0;
- info->event = 0;
info->tty = NULL;
if (info->blocked_open) {
spin_unlock_irqrestore(&card->card_lock, flags);
@@ -4444,7 +4375,6 @@ static void cy_hangup(struct tty_struct *tty)
cy_flush_buffer(tty);
shutdown(info);
- info->event = 0;
info->count = 0;
#ifdef CY_DEBUG_COUNT
printk(KERN_DEBUG "cyc:cy_hangup (%d): setting count to 0\n",
@@ -4502,7 +4432,6 @@ static int __devinit cy_init_card(struct cyclades_card *cinfo)
info->closing_wait = CLOSING_WAIT_DELAY;
info->close_delay = 5 * HZ / 10;
- INIT_WORK(&info->tqueue, do_softint);
init_waitqueue_head(&info->open_wait);
init_waitqueue_head(&info->close_wait);
init_completion(&info->shutdown_wait);
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