[PATCH 3.12 66/83] sb_edac: avoid INTERNAL ERROR message in EDAC with unspecified channel

From: Jiri Slaby
Date: Mon Apr 27 2015 - 17:34:48 EST


From: Seth Jennings <sjenning@xxxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit 351fc4a99d49fde63fe5ab7412beb35c40d27269 upstream.

Intel IA32 SDM Table 15-14 defines channel 0xf as 'not specified', but
EDAC doesn't know about this and returns and INTERNAL ERROR when the
channel is greater than NUM_CHANNELS:

kernel: [ 1538.886456] CPU 0: Machine Check Exception: 0 Bank 1: 940000000000009f
kernel: [ 1538.886669] TSC 2bc68b22e7e812 ADDR 46dae7000 MISC 0 PROCESSOR 0:306e4 TIME 1390414572 SOCKET 0 APIC 0
kernel: [ 1538.971948] EDAC MC1: INTERNAL ERROR: channel value is out of range (15 >= 4)
kernel: [ 1538.972203] EDAC MC1: 0 CE memory read error on unknown memory (slot:0 page:0x46dae7 offset:0x0 grain:0 syndrome:0x0 - area:DRAM err_code:0000:009f socket:1 channel_mask:1 rank:0)

This commit changes sb_edac to forward a channel of -1 to EDAC if the
channel is not specified. edac_mc_handle_error() sets the channel to -1
internally after the error message anyway, so this commit should have no
effect other than avoiding the INTERNAL ERROR message when the channel
is not specified.

Signed-off-by: Seth Jennings <sjenning@xxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/edac/sb_edac.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/edac/sb_edac.c b/drivers/edac/sb_edac.c
index 952a956288e4..3bdefbfb4377 100644
--- a/drivers/edac/sb_edac.c
+++ b/drivers/edac/sb_edac.c
@@ -270,8 +270,9 @@ static const u32 correrrthrsld[] = {
* sbridge structs
*/

-#define NUM_CHANNELS 4
-#define MAX_DIMMS 3 /* Max DIMMS per channel */
+#define NUM_CHANNELS 4
+#define MAX_DIMMS 3 /* Max DIMMS per channel */
+#define CHANNEL_UNSPECIFIED 0xf /* Intel IA32 SDM 15-14 */

struct sbridge_info {
u32 mcmtr;
@@ -1453,6 +1454,9 @@ static void sbridge_mce_output_error(struct mem_ctl_info *mci,

/* FIXME: need support for channel mask */

+ if (channel == CHANNEL_UNSPECIFIED)
+ channel = -1;
+
/* Call the helper to output message */
edac_mc_handle_error(tp_event, mci, core_err_cnt,
m->addr >> PAGE_SHIFT, m->addr & ~PAGE_MASK, 0,
--
2.3.5

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