From 8b67f8c177a642b35b7a05f530c12ef2834ef182 Mon Sep 17 00:00:00 2001 From: Milton Miller Date: Thu, 7 Jul 2005 17:56:18 -0700 Subject: [PATCH] [PATCH] hvc_console: Dont always kick the poll thread in interrupt 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 Signed-off-by: Anton Blanchard Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/hvc_console.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c index 4b776f4eb467..46508a737064 100644 --- a/drivers/char/hvc_console.c +++ b/drivers/char/hvc_console.c @@ -254,13 +254,17 @@ static void hvc_kick(void) 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. * In this case the console is poll driven. */ 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; } @@ -598,8 +602,8 @@ static int hvc_poll(struct hvc_struct *hp) /* * 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 - * data and eventually throttle us. + * 64 bytes, we do a quick schedule loop to let the tty grok + * the data and eventually throttle us. */ read_total += n; if (read_total >= 64) { -- 2.20.1