[4.2.y-ckt stable] Patch "aacraid: Fix for KDUMP driver hang" has been added to the 4.2.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    aacraid: Fix for KDUMP driver hang

to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree 
which can be found at:

    https://git.launchpad.net/~canonical-kernel/linux/+git/linux-stable-ckt/log/?h=linux-4.2.y-queue

This patch is scheduled to be released in version 4.2.8-ckt12.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From 5746c2d9e154d2083fa8f8ff72400e03f6b11083 Mon Sep 17 00:00:00 2001
From: Raghava Aditya Renukunta <RaghavaAditya.Renukunta at microsemi.com>
Date: Mon, 25 Apr 2016 23:32:37 -0700
Subject: aacraid: Fix for KDUMP driver hang

commit 78cbccd3bd683c295a44af8050797dc4a41376ff upstream.

When KDUMP is triggered the driver first talks to the firmware in INTX
mode, but the adapter firmware is still in MSIX mode. Therefore the first
driver command hangs since the driver is waiting for an INTX response and
firmware gives a MSIX response. If when the OS is installed on a RAID
drive created by the adapter KDUMP will hang since the driver does not
receive a response in sync mode.

Fixed by: Change the firmware to INTX mode if it is in MSIX mode before
sending the first sync command.

Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta at microsemi.com>
Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/scsi/aacraid/aacraid.h  |  1 +
 drivers/scsi/aacraid/comminit.c | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h
index 18c9c06..3e8e92b 100644
--- a/drivers/scsi/aacraid/aacraid.h
+++ b/drivers/scsi/aacraid/aacraid.h
@@ -29,6 +29,7 @@ enum {
 #define AAC_INT_MODE_MSI		(1<<1)
 #define AAC_INT_MODE_AIF		(1<<2)
 #define AAC_INT_MODE_SYNC		(1<<3)
+#define AAC_INT_MODE_MSIX		(1<<16)

 #define AAC_INT_ENABLE_TYPE1_INTX	0xfffffffb
 #define AAC_INT_ENABLE_TYPE1_MSIX	0xfffffffa
diff --git a/drivers/scsi/aacraid/comminit.c b/drivers/scsi/aacraid/comminit.c
index 45db84a..e736ecb 100644
--- a/drivers/scsi/aacraid/comminit.c
+++ b/drivers/scsi/aacraid/comminit.c
@@ -37,6 +37,7 @@
 #include <linux/spinlock.h>
 #include <linux/slab.h>
 #include <linux/blkdev.h>
+#include <linux/delay.h>
 #include <linux/completion.h>
 #include <linux/mm.h>
 #include <scsi/scsi_host.h>
@@ -49,6 +50,20 @@ struct aac_common aac_config = {
 	.irq_mod = 1
 };

+static inline int aac_is_msix_mode(struct aac_dev *dev)
+{
+	u32 status;
+
+	status = src_readl(dev, MUnit.OMR);
+	return (status & AAC_INT_MODE_MSIX);
+}
+
+static inline void aac_change_to_intx(struct aac_dev *dev)
+{
+	aac_src_access_devreg(dev, AAC_DISABLE_MSIX);
+	aac_src_access_devreg(dev, AAC_ENABLE_INTX);
+}
+
 static int aac_alloc_comm(struct aac_dev *dev, void **commaddr, unsigned long commsize, unsigned long commalign)
 {
 	unsigned char *base;
@@ -358,6 +373,15 @@ struct aac_dev *aac_init_adapter(struct aac_dev *dev)
 	dev->comm_interface = AAC_COMM_PRODUCER;
 	dev->raw_io_interface = dev->raw_io_64 = 0;

+
+	/*
+	 * Enable INTX mode, if not done already Enabled
+	 */
+	if (aac_is_msix_mode(dev)) {
+		aac_change_to_intx(dev);
+		dev_info(&dev->pdev->dev, "Changed firmware to INTX mode");
+	}
+
 	if ((!aac_adapter_sync_cmd(dev, GET_ADAPTER_PROPERTIES,
 		0, 0, 0, 0, 0, 0,
 		status+0, status+1, status+2, status+3, NULL)) &&
--
2.7.4