Hi there,
I am trying to rewrite parts of file drivers/char/serial.c ,
making better IRQ detection (use of probe_irq_*())
and after cleanning, trying to support other chipset.
I have two typo in arch/i386/kernel/irq.c, linux 2.1.88 -
works also on 2.1.89:
(i<<1) instead of (1<<i) -- patch file at end of message
(sorry it is a reverse patch) (Linus, are you there ?)
I also like to know what people think of the two functions
added in this file, that would enable faster IRQ detection;
and if it is accepted some adds from the SMP people to
detect SMP special IRQ which are waiting (pending and
not enabled) - and maybe currently treated.
With those, detecting an IRQ would be done by:
- get all currently pending IRQ - not enable new ones
- save number of enabled and treated IRQ
- make new chip generate the IRQ to detect
- see if a new pending IRQ appear
that will be the usual case and will be faster
- else, wait 100 ms to check for wild interrupt
- and continue the probe_irq_* process
In this patch, there is also small modification to
display on a "cat /proc/interrupt" the line where
there is no action at present but there was some
(nb IRQ not null).
Thanks for reading,
Etienne Lorrain.
-- etienne.lorrain@ibm.net
-- On ne voit bien qu'avec le coeur,
-- l'essentiel est invisible pour les yeux. St Exupery.
----------- etienne.lorrain@ibm.net
-- hdc: irq timeout: status=0xd0 { Busy }
-- ide1: reset: success
----------> I like Linux !
--Message-Boundary-7336
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Text from file 'irqpatch.txt'
diff -ur linux-2.1.88-patched/arch/i386/kernel/irq.c linux/arch/i386/kernel/irq.c
--- linux-2.1.88-patched/arch/i386/kernel/irq.c Sat Mar 7 13:23:57 1998
+++ linux/arch/i386/kernel/irq.c Sun Mar 8 21:52:24 1998
@@ -176,30 +176,6 @@
}
}
-unsigned get_8259A_irq_in_treatment(void)
-{
- /* Read PIC1 and PIC2 ISR : */
- return (inb(0xA0) << 8) | inb(0x20);
-}
-
-unsigned get_8259A_irq_waiting(void)
-{
- register unsigned returned;
- unsigned long flags;
-
- save_flags(flags); cli();
- /* Set PICs to read Interrupt Request Register at address 0x20/0xA0 : */
- outb(0x0A, 0xA0);
- outb(0x0A, 0x20);
- /* Read PIC2 and PIC1 IRR : */
- returned = (inb(0xA0) << 8) | inb(0x20);
- /* Reset PICs to read In Service Register at address 0x20/0xA0 : */
- outb(0x0B, 0x20);
- outb(0x0B, 0xA0);
- restore_flags(flags);
- return returned;
-}
-
void unmask_generic_irq(unsigned int irq)
{
if (IO_APIC_IRQ(irq))
@@ -232,7 +208,7 @@
#ifdef __SMP__
/*
- * The IO-APIC (present only in SMP boards) has 8 more hardware
+ * The IO-APIC (persent only in SMP boards) has 8 more hardware
* interrupt pins, for all of them we define an IRQ vector:
*
* raw PCI interrupts 0-3, basically these are the ones used
@@ -294,12 +270,8 @@
/*
* Initial irq handlers.
*/
-static unsigned nb_IRQ_no_action = 0;
-static void no_action(int cpl, void *dev_id, struct pt_regs *regs)
-{
- nb_IRQ_no_action++;
-}
+static void no_action(int cpl, void *dev_id, struct pt_regs *regs) { }
/*
* Note that on a 486, we don't want to do a SIGFPE on an irq13
@@ -352,7 +324,7 @@
for (i = 0 ; i < NR_IRQS ; i++) {
action = irq_action[i];
- if (!action && !kstat_irqs(i))
+ if (!action)
continue;
p += sprintf(p, "%3d: ",i);
#ifndef __SMP__
@@ -367,18 +339,14 @@
p += sprintf(p, " IO-APIC ");
else
p += sprintf(p, " XT PIC ");
+ p += sprintf(p, " %s", action->name);
- if (action) {
- p += sprintf(p, " %s", action->name);
- for (action=action->next; action; action = action->next)
- p += sprintf(p, ", %s", action->name);
- } else
- p += sprintf(p, " unregistered");
+ for (action=action->next; action; action = action->next) {
+ p += sprintf(p, ", %s", action->name);
+ }
*p++ = '\n';
}
p += sprintf(p, "NMI: %10u\n", atomic_read(&nmi_counter));
- if (nb_IRQ_no_action)
- p += sprintf(p, "Unaffected: %3u\n", nb_IRQ_no_action);
#ifdef __SMP__
p += sprintf(p, "IPI: %10lu\n", ipi_count);
#endif
@@ -1025,7 +993,7 @@
for (i=0; i<NR_IRQS; i++)
for (j=0; j<NR_CPUS; j++)
if (kstat.irqs[j][i] != probe_irqs[j][i])
- irqs &= ~(1<<i);
+ irqs &= ~(i<<1);
return irqs;
}
@@ -1040,7 +1008,7 @@
sum += kstat.irqs[j][i];
sum -= probe_irqs[j][i];
}
- if (sum && (irqs & (1<<i))) {
+ if (sum && (irqs & (i<<1))) {
if (irq_found != -1) {
irq_found = -irq_found;
goto out;
--Message-Boundary-7336--
-
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