When we parse a device's _CRS data (the current resource settings),
we should keep track of everything we find, even if it's currently
disabled or invalid.

This is what we already do for ISAPNP and PNPBIOS, and it helps
keep things matched up when we subsequently re-encode resources.
For example, consider a device with (mem, irq0, irq1, io), where
irq0 is disabled.  If we drop irq0 when parsing the _CRS, we will
mistakenly put irq1 in the irq0 slot when we encode resources
for an _SRS call.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: work14/drivers/pnp/pnpacpi/rsparser.c
===================================================================
--- work14.orig/drivers/pnp/pnpacpi/rsparser.c	2008-06-17 14:47:29.000000000 -0600
+++ work14/drivers/pnp/pnpacpi/rsparser.c	2008-06-17 15:46:52.000000000 -0600
@@ -98,8 +98,10 @@ static void pnpacpi_parse_allocated_irqr
 	int irq, flags;
 	int p, t;
 
-	if (!valid_IRQ(gsi))
+	if (!valid_IRQ(gsi)) {
+		pnp_add_irq_resource(dev, gsi, IORESOURCE_DISABLED);
 		return;
+	}
 
 	/*
 	 * in IO-APIC mode, use overrided attribute. Two reasons:
@@ -248,24 +250,39 @@ static acpi_status pnpacpi_allocated_res
 		 * _CRS, but some firmware violates this, so parse them all.
 		 */
 		irq = &res->data.irq;
-		for (i = 0; i < irq->interrupt_count; i++) {
-			pnpacpi_parse_allocated_irqresource(dev,
-				irq->interrupts[i],
-				irq->triggering,
-				irq->polarity,
-				irq->sharable);
+		if (irq->interrupt_count == 0)
+			pnp_add_irq_resource(dev, 0, IORESOURCE_DISABLED);
+		else {
+			for (i = 0; i < irq->interrupt_count; i++) {
+				pnpacpi_parse_allocated_irqresource(dev,
+					irq->interrupts[i],
+					irq->triggering,
+					irq->polarity,
+				    irq->sharable);
+			}
+
+			/*
+			 * The IRQ encoder puts a single interrupt in each
+			 * descriptor, so if a _CRS descriptor has more than
+			 * one interrupt, we won't be able to re-encode it.
+			 */
+			if (pnp_can_write(dev) && irq->interrupt_count > 1) {
+				dev_warn(&dev->dev, "multiple interrupts in "
+					 "_CRS descriptor; configuration can't "
+					 "be changed\n");
+				dev->capabilities &= ~PNP_WRITE;
+			}
 		}
 		break;
 
 	case ACPI_RESOURCE_TYPE_DMA:
 		dma = &res->data.dma;
-		if (dma->channel_count > 0) {
+		if (dma->channel_count > 0 && dma->channels[0] != (u8) -1)
 			flags = dma_flags(dma->type, dma->bus_master,
 					  dma->transfer);
-			if (dma->channels[0] == (u8) -1)
-				flags |= IORESOURCE_DISABLED;
-			pnp_add_dma_resource(dev, dma->channels[0], flags);
-		}
+		else
+			flags = IORESOURCE_DISABLED;
+		pnp_add_dma_resource(dev, dma->channels[0], flags);
 		break;
 
 	case ACPI_RESOURCE_TYPE_IO:
@@ -331,12 +348,29 @@ static acpi_status pnpacpi_allocated_res
 		if (extended_irq->producer_consumer == ACPI_PRODUCER)
 			return AE_OK;
 
-		for (i = 0; i < extended_irq->interrupt_count; i++) {
-			pnpacpi_parse_allocated_irqresource(dev,
-				extended_irq->interrupts[i],
-				extended_irq->triggering,
-				extended_irq->polarity,
-				extended_irq->sharable);
+		if (extended_irq->interrupt_count == 0)
+			pnp_add_irq_resource(dev, 0, IORESOURCE_DISABLED);
+		else {
+			for (i = 0; i < extended_irq->interrupt_count; i++) {
+				pnpacpi_parse_allocated_irqresource(dev,
+					extended_irq->interrupts[i],
+					extended_irq->triggering,
+					extended_irq->polarity,
+					extended_irq->sharable);
+			}
+
+			/*
+			 * The IRQ encoder puts a single interrupt in each
+			 * descriptor, so if a _CRS descriptor has more than
+			 * one interrupt, we won't be able to re-encode it.
+			 */
+			if (pnp_can_write(dev) &&
+			    extended_irq->interrupt_count > 1) {
+				dev_warn(&dev->dev, "multiple interrupts in "
+					 "_CRS descriptor; configuration can't "
+					 "be changed\n");
+				dev->capabilities &= ~PNP_WRITE;
+			}
 		}
 		break;
 

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