mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

MIPS: Alchemy: Fix hang with high-frequency edge interrupts 

The handle_edge_irq() flowhandler disables edge int sources which occur
too fast (i.e. another edge comes in before the irq handler function
had a chance to finish).  Currently, the mask_ack() callback does not
ack the edges in hardware, leading to an endless loop in the flowhandler
where it tries to shut up the irq source.

When I rewrote the alchemy IRQ code  I wrongly assumed the mask_ack()
callback was only used by the level flowhandler, hence it omitted the
(at the time pointless) edge acks.  Turned out I was wrong; so here
is a complete mask_ack implementation for Alchemy IC, which fixes
the above mentioned problem.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Manuel Lauss 2009-10-14 12:22:20 +02:00 committed by Ralf Baechle
parent fcc152f3bf
commit 44f2c586a3
1 changed files with 26 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
arch/mips/alchemy/common/irq.c
View File

@ -354,6 +354,28 @@ static void au1x_ic1_ack(unsigned int irq_nr)
au_sync();
}
static void au1x_ic0_maskack(unsigned int irq_nr)
{
unsigned int bit = irq_nr - AU1000_INTC0_INT_BASE;
au_writel(1 << bit, IC0_WAKECLR);
au_writel(1 << bit, IC0_MASKCLR);
au_writel(1 << bit, IC0_RISINGCLR);
au_writel(1 << bit, IC0_FALLINGCLR);
au_sync();
}
static void au1x_ic1_maskack(unsigned int irq_nr)
{
unsigned int bit = irq_nr - AU1000_INTC1_INT_BASE;
au_writel(1 << bit, IC1_WAKECLR);
au_writel(1 << bit, IC1_MASKCLR);
au_writel(1 << bit, IC1_RISINGCLR);
au_writel(1 << bit, IC1_FALLINGCLR);
au_sync();
}
static int au1x_ic1_setwake(unsigned int irq, unsigned int on)
{
unsigned int bit = irq - AU1000_INTC1_INT_BASE;
@ -379,25 +401,21 @@ static int au1x_ic1_setwake(unsigned int irq, unsigned int on)
/*
* irq_chips for both ICs; this way the mask handlers can be
* as short as possible.
*
* NOTE: the ->ack() callback is used by the handle_edge_irq
* flowhandler only, the ->mask_ack() one by handle_level_irq,
* so no need for an irq_chip for each type of irq (level/edge).
*/
static struct irq_chip au1x_ic0_chip = {
.name = "Alchemy-IC0",
.ack = au1x_ic0_ack, /* edge */
.ack = au1x_ic0_ack,
.mask = au1x_ic0_mask,
.mask_ack = au1x_ic0_mask, /* level */
.mask_ack = au1x_ic0_maskack,
.unmask = au1x_ic0_unmask,
.set_type = au1x_ic_settype,
};
static struct irq_chip au1x_ic1_chip = {
.name = "Alchemy-IC1",
.ack = au1x_ic1_ack, /* edge */
.ack = au1x_ic1_ack,
.mask = au1x_ic1_mask,
.mask_ack = au1x_ic1_mask, /* level */
.mask_ack = au1x_ic1_maskack,
.unmask = au1x_ic1_unmask,
.set_type = au1x_ic_settype,
.set_wake = au1x_ic1_setwake,