Fix very high interrupt rate for IRQ8 (rtc) unless pnpacpi=off

Workaround for broken systems with BIOS that makes RTC interrupt level triggered and/or active low. See http://bugzilla.kernel.org/show_bug.cgi?id=5243 Based on the patch from Shaohua Li <[email protected]> Signed-off-by: Krzysztof Piotr Oledzki <[email protected]> Cc: "Li, Shaohua" <[email protected]> Cc: Bjorn Helgaas <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Adam Belay <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
neviim · Oct 17, 2007 · 9cd8047 · 9cd8047
1 parent 7ef3639
commit 9cd8047
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/drivers/pnp/pnpacpi/rsparser.c b/drivers/pnp/pnpacpi/rsparser.c
@@ -85,6 +85,16 @@ static void pnpacpi_parse_allocated_irqresource(struct pnp_resource_table *res,
 	if (i >= PNP_MAX_IRQ)
 		return;
 
+#ifdef CONFIG_X86
+	if (gsi < 16 && (triggering != ACPI_EDGE_SENSITIVE ||
+				polarity != ACPI_ACTIVE_HIGH)) {
+		pnp_warn("BIOS BUG: legacy PNP IRQ %d should be edge trigger, "
+				"active high", gsi);
+		triggering = ACPI_EDGE_SENSITIVE;
+		polarity = ACPI_ACTIVE_HIGH;
+	}
+#endif
+
 	res->irq_resource[i].flags = IORESOURCE_IRQ;	// Also clears _UNSET flag
 	res->irq_resource[i].flags |= irq_flags(triggering, polarity);
 	irq = acpi_register_gsi(gsi, triggering, polarity);