linux-kernel - [PATCH] amd64_edac: Rewrite unganged mode code of f10_early_channel

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Date:	Fri, 7 Aug 2009 22:39:39 +0800
From:	wan wei <onewayforever@...il.com>
To:	borislav.petkov@....com, dougthompson@...ssion.com
Cc:	linux-kernel@...r.kernel.org
Subject: [PATCH] amd64_edac: Rewrite unganged mode code of 
	f10_early_channel_count

simplify the procedure by checking if there is any dimm  in each channel.
this patch will fix the bugs such as when there is no dimms  under
certain node,  two dimms in the same channel, and only one dimm in
each channel of the node.

Signed-off-by: Wan Wei<wanwei@...l.dawning.com.cn>
---
 drivers/edac/amd64_edac.c |   43 ++++++++++---------------------------------
 1 files changed, 10 insertions(+), 33 deletions(-)

diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
index e2a10bc..acf9cfe 100644
--- a/drivers/edac/amd64_edac.c
+++ b/drivers/edac/amd64_edac.c
@@ -1200,6 +1200,8 @@ static int f10_early_channel_count(struct amd64_pvt *pvt)
 {
 	int err = 0, channels = 0;
 	u32 dbam;
+	int i, j;
+	int dbams[] = { DBAM0, DBAM1 };

 	err = pci_read_config_dword(pvt->dram_f2_ctl, F10_DCLR_0, &pvt->dclr0);
 	if (err)
@@ -1232,45 +1234,20 @@ static int f10_early_channel_count(struct
amd64_pvt *pvt)
 	 * both controllers since DIMMs can be placed in either one.
 	 */
 	channels = 0;
-	err = pci_read_config_dword(pvt->dram_f2_ctl, DBAM0, &dbam);
-	if (err)
-		goto err_reg;

-	if (DBAM_DIMM(0, dbam) > 0)
-		channels++;
-	if (DBAM_DIMM(1, dbam) > 0)
-		channels++;
-	if (DBAM_DIMM(2, dbam) > 0)
-		channels++;
-	if (DBAM_DIMM(3, dbam) > 0)
-		channels++;
-
-	/* If more than 2 DIMMs are present, then we have 2 channels */
-	if (channels > 2)
-		channels = 2;
-	else if (channels == 0) {
-		/* No DIMMs on DCT0, so look at DCT1 */
-		err = pci_read_config_dword(pvt->dram_f2_ctl, DBAM1, &dbam);
+	for (i = 0; i < ARRAY_SIZE(dbams); i++) {
+		err = pci_read_config_dword(pvt->dram_f2_ctl, dbams[i], &dbam);
 		if (err)
 			goto err_reg;

-		if (DBAM_DIMM(0, dbam) > 0)
-			channels++;
-		if (DBAM_DIMM(1, dbam) > 0)
-			channels++;
-		if (DBAM_DIMM(2, dbam) > 0)
-			channels++;
-		if (DBAM_DIMM(3, dbam) > 0)
-			channels++;
-
-		if (channels > 2)
-			channels = 2;
+		for (j = 0; j < 4; j++) {
+			if (DBAM_DIMM(j, dbam) > 0) {
+				channels++;
+				break;
+			}
+		}
 	}

-	/* If we found ALL 0 values, then assume just ONE DIMM-ONE Channel */
-	if (channels == 0)
-		channels = 1;
-
 	debugf0("MCT channel count: %d\n", channels);

 	return channels;
-- 
1.4.4.2
--
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