From fc844f7bfbf08f6705efa5303b11dcbf54f2dde8 Mon Sep 17 00:00:00 2001
From: Michael Lotz <mmlr@mlotz.ch>
Date: Fri, 15 Jan 2010 19:21:52 +0000
Subject: [PATCH] * Don't call into the ATA stack if we're not transferring
 data since the   interrupt could be triggered early in the boot process where
 the ATA channel   might not yet be fully set up leading to KDLs accessing
 uninitialized memory. * Automatic whitespace cleanup

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35087 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 .../kernel/generic/ata_adapter/ata_adapter.c  | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/add-ons/kernel/generic/ata_adapter/ata_adapter.c b/src/add-ons/kernel/generic/ata_adapter/ata_adapter.c
index 088a196f31..1a885d61bb 100644
--- a/src/add-ons/kernel/generic/ata_adapter/ata_adapter.c
+++ b/src/add-ons/kernel/generic/ata_adapter/ata_adapter.c
@@ -25,7 +25,7 @@
 #define TRACE dprintf
 
 #define INTERRUPT_TRACING 0
-#if INTERRUPT_TRACING 
+#if INTERRUPT_TRACING
 	#define TRACE_INT(a...) 	ktrace_printf(a)
 #else
 	#define TRACE_INT(a...)
@@ -213,11 +213,18 @@ ata_adapter_inthand(void *arg)
 		statusATA = pci->read_io_8(device, channel->command_block_base + 7);
 		TRACE_INT("ata_adapter_inthand: ATA-status 0x%02x\n", statusATA);
 
-		// clear pending PCI bus master DMA interrupt, for those 
+		// clear pending PCI bus master DMA interrupt, for those
 		// controllers who don't clear it themselves
 		pci->write_io_8(device, channel->bus_master_base + ATA_BM_STATUS_REG,
 			(statusBM & 0xf8) | ATA_BM_STATUS_INTERRUPT);
 
+		if (!channel->dmaing) {
+			// we check this late so that potential spurious interrupts
+			// are acknoledged above
+			TRACE_INT("ata_adapter_inthand: no DMA transfer active\n");
+			return B_UNHANDLED_INTERRUPT;
+		}
+
 		// signal interrupt to ATA stack
 		return sATA->interrupt_handler(channel->ataChannel, statusATA);
 	} else {
@@ -238,7 +245,7 @@ ata_adapter_prepare_dma(ata_adapter_channel_info *channel,
 	prd_entry *prd = channel->prdt;
 	int i;
 
-	TRACE_DMA("ata_adapter: prepare_dma (%s) %u entrys:\n", 
+	TRACE_DMA("ata_adapter: prepare_dma (%s) %u entrys:\n",
 		writeToDevice ? "write" : "read", sgListCount);
 
 	for (i = sgListCount - 1, prd = channel->prdt; i >= 0; --i, ++prd, ++sgList) {
@@ -247,7 +254,7 @@ ata_adapter_prepare_dma(ata_adapter_channel_info *channel,
 		prd->count = B_HOST_TO_LENDIAN_INT16((uint16)sgList->size);
 		prd->EOT = i == 0;
 
-		TRACE_DMA("ata_adapter: %p, %ld => 0x%08x, %d, %d\n", 
+		TRACE_DMA("ata_adapter: %p, %ld => 0x%08x, %d, %d\n",
 			sgList->address, sgList->size, prd->address, prd->count, prd->EOT);
 		SHOW_FLOW( 4, "%x, %x, %d", (int)prd->address, prd->count, prd->EOT);
 	}
@@ -564,7 +571,7 @@ ata_adapter_detect_channel(pci_device_module_info *pci, pci_device *pci_device,
 	}
 	if (pcicmdOld != pcicmdNew) {
 		pci->write_pci_config(pci_device, PCI_command, 2, pcicmdNew);
-		TRACE("PCI-ATA: pcicmd changed from 0x%04x to 0x%04x\n", 
+		TRACE("PCI-ATA: pcicmd changed from 0x%04x to 0x%04x\n",
 			pcicmdOld, pcicmdNew);
 	}
 
@@ -644,7 +651,7 @@ ata_adapter_init_controller(device_node *node,
 	}
 	if (pcicmdOld != pcicmdNew) {
 		pci->write_pci_config(node, PCI_command, 2, pcicmdNew);
-		TRACE("PCI-ATA: adapter init: pcicmd old 0x%04x, new 0x%04x\n", 
+		TRACE("PCI-ATA: adapter init: pcicmd old 0x%04x, new 0x%04x\n",
 			pcicmdOld, pcicmdNew);
 	}
 #endif