mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-08-21 00:10:09 +00:00
Code Issues Releases Wiki Activity

arm/imx/gpio: use fls to find set bits in the irq status register

Browse source 
As in most cases only few irqs are pending using fls is more effective
than looping over all bits.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
This commit is contained in:
Uwe Kleine-König 2010-02-08 21:02:30 +01:00
parent 3244c3e779
commit 3621f188b9
1 changed files with 9 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

20
arch/arm/plat-mxc/gpio.c
View file

@ -154,24 +154,22 @@ static void mxc_flip_edge(struct mxc_gpio_port *port, u32 gpio)
__raw_writel(val | (edge << (bit << 1)), reg);
}
/* handle n interrupts in one status register */
/* handle 32 interrupts in one status register */
static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat)
{
u32 gpio_irq_no;
u32 gpio_irq_no_base = port->virtual_irq_start;
gpio_irq_no = port->virtual_irq_start;
for (; irq_stat != 0; irq_stat >>= 1, gpio_irq_no++) {
u32 gpio = irq_to_gpio(gpio_irq_no);
while (irq_stat != 0) {
int irqoffset = fls(irq_stat) - 1;
if ((irq_stat & 1) == 0)
continue;
BUG_ON(!(irq_desc[gpio_irq_no_base + irqoffset].handle_irq));
BUG_ON(!(irq_desc[gpio_irq_no].handle_irq));
if (port->both_edges & (1 << irqoffset))
mxc_flip_edge(port, irqoffset);
if (port->both_edges & (1 << (gpio & 31)))
mxc_flip_edge(port, gpio);
generic_handle_irq(gpio_irq_no_base + irqoffset);
generic_handle_irq(gpio_irq_no);
irq_stat &= ~(1 << irqoffset);
}
}