Commit 691874fa authored by Maciej W. Rozycki's avatar Maciej W. Rozycki Committed by Ingo Molnar
Browse files

x86: I/O APIC: timer through 8259A second-chance 



Some systems incorrectly report the ExtINTA pin of the I/O APIC as the
genuine target of the timer interrupt.  Here is a change that copies timer
pin information found to the other pin if one has been found only.  This
way both a direct and a through-8259A route is tested with the pin letting
these problematic systems work well enough.  If no timer pin information
has been found for the I/O APIC, then local APIC variations are tried
only, similarly to what is done without the change (except without the
misleading messages).

Obviously if we try the first-chance path without being told by the BIOS
to do so, we should not complain either, so do not print the message in
this case.

The 64-bit variation should be updated with a call to
replace_pin_at_irq() which can be done with the upcoming merge.  Since
add_pin_to_irq() is now always called in the first-chance path, the
condition to require it in the second-chance path no longer happens.

Signed-off-by: default avatarMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 03be7505

arch/x86/kernel/io_apic_32.c

+28 −10
Original line number Diff line number Diff line
@@ -2122,6 +2122,7 @@ static inline void __init unlock_ExtINT_logic(void) 
static inline void __init check_timer(void)

{

	int apic1, pin1, apic2, pin2;

	int no_pin1 = 0;

	int vector;

	unsigned int ver;

	unsigned long flags;
@@ -2159,10 +2160,30 @@ static inline void __init check_timer(void) 
	printk(KERN_INFO "..TIMER: vector=0x%02X apic1=%d pin1=%d apic2=%d pin2=%d\n",

		vector, apic1, pin1, apic2, pin2);



	/*

	 * Some BIOS writers are clueless and report the ExtINTA

	 * I/O APIC input from the cascaded 8259A as the timer

	 * interrupt input.  So just in case, if only one pin

	 * was found above, try it both directly and through the

	 * 8259A.

	 */

	if (pin1 == -1) {

		pin1 = pin2;

		apic1 = apic2;

		no_pin1 = 1;

	} else if (pin2 == -1) {

		pin2 = pin1;

		apic2 = apic1;

	}



	if (pin1 != -1) {

		/*

		 * Ok, does IRQ0 through the IOAPIC work?

		 */

		if (no_pin1) {

			add_pin_to_irq(0, apic1, pin1);

			setup_timer_IRQ0_pin(apic1, pin1, vector);

		}

		unmask_IO_APIC_irq(0);

		if (timer_irq_works()) {

			if (nmi_watchdog == NMI_IO_APIC) {
@@ -2174,26 +2195,23 @@ static inline void __init check_timer(void) 
			goto out;

		}

		clear_IO_APIC_pin(apic1, pin1);

		printk(KERN_ERR "..MP-BIOS bug: 8254 timer not connected to "

				"IO-APIC\n");

	}

		if (!no_pin1)

			printk(KERN_ERR "..MP-BIOS bug: "

			       "8254 timer not connected to IO-APIC\n");



	printk(KERN_INFO "...trying to set up timer (IRQ0) through the 8259A ... ");

	if (pin2 != -1) {

		printk(KERN_INFO "...trying to set up timer (IRQ0) "

		       "through the 8259A ... ");

		printk("\n..... (found pin %d) ...", pin2);

		/*

		 * legacy devices should be connected to IO APIC #0

		 */

		replace_pin_at_irq(0, apic1, pin1, apic2, pin2);

		setup_timer_IRQ0_pin(apic2, pin2, vector);

		unmask_IO_APIC_irq(0);

		enable_8259A_irq(0);

		if (timer_irq_works()) {

			printk("works.\n");

			timer_through_8259 = 1;

			if (pin1 != -1)

				replace_pin_at_irq(0, apic1, pin1, apic2, pin2);

			else

				add_pin_to_irq(0, apic2, pin2);

			if (nmi_watchdog == NMI_IO_APIC) {

				disable_8259A_irq(0);

				setup_nmi();
@@ -2206,8 +2224,8 @@ static inline void __init check_timer(void) 
		 */

		disable_8259A_irq(0);

		clear_IO_APIC_pin(apic2, pin2);

	}

		printk(" failed.\n");

	}



	if (nmi_watchdog == NMI_IO_APIC) {

		printk(KERN_WARNING "timer doesn't work through the IO-APIC - disabling NMI Watchdog!\n");

arch/x86/kernel/io_apic_64.c

+29 −7
Original line number Diff line number Diff line
@@ -1638,6 +1638,7 @@ static inline void __init check_timer(void) 
	struct irq_cfg *cfg = irq_cfg + 0;

	int apic1, pin1, apic2, pin2;

	unsigned long flags;

	int no_pin1 = 0;



	local_irq_save(flags);
@@ -1662,10 +1663,30 @@ static inline void __init check_timer(void) 
	apic_printk(APIC_VERBOSE,KERN_INFO "..TIMER: vector=0x%02X apic1=%d pin1=%d apic2=%d pin2=%d\n",

		cfg->vector, apic1, pin1, apic2, pin2);



	/*

	 * Some BIOS writers are clueless and report the ExtINTA

	 * I/O APIC input from the cascaded 8259A as the timer

	 * interrupt input.  So just in case, if only one pin

	 * was found above, try it both directly and through the

	 * 8259A.

	 */

	if (pin1 == -1) {

		pin1 = pin2;

		apic1 = apic2;

		no_pin1 = 1;

	} else if (pin2 == -1) {

		pin2 = pin1;

		apic2 = apic1;

	}



	if (pin1 != -1) {

		/*

		 * Ok, does IRQ0 through the IOAPIC work?

		 */

		if (no_pin1) {

			add_pin_to_irq(0, apic1, pin1);

			setup_timer_IRQ0_pin(apic1, pin1, vector);

		}

		unmask_IO_APIC_irq(0);

		if (!no_timer_check && timer_irq_works()) {

			nmi_watchdog_default();
@@ -1678,18 +1699,19 @@ static inline void __init check_timer(void) 
			goto out;

		}

		clear_IO_APIC_pin(apic1, pin1);

		apic_printk(APIC_QUIET,KERN_ERR "..MP-BIOS bug: 8254 timer not "

				"connected to IO-APIC\n");

	}

		if (!no_pin1)

			apic_printk(APIC_QUIET,KERN_ERR "..MP-BIOS bug: "

				    "8254 timer not connected to IO-APIC\n");



	apic_printk(APIC_VERBOSE,KERN_INFO "...trying to set up timer (IRQ0) "

		apic_printk(APIC_VERBOSE,KERN_INFO

			"...trying to set up timer (IRQ0) "

			"through the 8259A ... ");

	if (pin2 != -1) {

		apic_printk(APIC_VERBOSE,"\n..... (found apic %d pin %d) ...",

			apic2, pin2);

		/*

		 * legacy devices should be connected to IO APIC #0

		 */

		/* replace_pin_at_irq(0, apic1, pin1, apic2, pin2); */

		setup_timer_IRQ0_pin(apic2, pin2, cfg->vector);

		unmask_IO_APIC_irq(0);

		enable_8259A_irq(0);
@@ -1709,8 +1731,8 @@ static inline void __init check_timer(void) 
		 */

		disable_8259A_irq(0);

		clear_IO_APIC_pin(apic2, pin2);

	}

		apic_printk(APIC_VERBOSE," failed.\n");

	}



	if (nmi_watchdog == NMI_IO_APIC) {

		printk(KERN_WARNING "timer doesn't work through the IO-APIC - disabling NMI Watchdog!\n");

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