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[PATCH] hvc_console: Dont always kick the poll thread in interrupt

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Have the hvc console code try to pull characters immediately when receiving an
interrupt, and kick the poll thread only if the immediate poll indicates it
needed a call back to do more work.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Milton Miller
2005-07-07 17:56:18 -07:00
committed by Linus Torvalds
parent 6f24808eeb
commit 8b67f8c177
1 changed files with 7 additions and 3 deletions
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10
drivers/char/hvc_console.c
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@@ -254,13 +254,17 @@ static void hvc_kick(void)
wake_up_process(hvc_task); wake_up_process(hvc_task);
} }
static int hvc_poll(struct hvc_struct *hp);
/* /*
* NOTE: This API isn't used if the console adapter doesn't support interrupts. * NOTE: This API isn't used if the console adapter doesn't support interrupts.
* In this case the console is poll driven. * In this case the console is poll driven.
*/ */
static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance, struct pt_regs *regs) static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance, struct pt_regs *regs)
{ {
hvc_kick(); /* if hvc_poll request a repoll, then kick the hvcd thread */
if (hvc_poll(dev_instance))
hvc_kick();
return IRQ_HANDLED; return IRQ_HANDLED;
} }
@@ -598,8 +602,8 @@ static int hvc_poll(struct hvc_struct *hp)
/* /*
* Account for the total amount read in one loop, and if above * Account for the total amount read in one loop, and if above
* 64 bytes, we do a quick schedule loop to let the tty grok the * 64 bytes, we do a quick schedule loop to let the tty grok
* data and eventually throttle us. * the data and eventually throttle us.
*/ */
read_total += n; read_total += n;
if (read_total >= 64) { if (read_total >= 64) {