Patch "aacraid: Fix for KDUMP driver hang" has been added to the 4.4-stable tree

Patch "aacraid: Fix for KDUMP driver hang" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    aacraid: Fix for KDUMP driver hang

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     aacraid-fix-for-kdump-driver-hang.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 78cbccd3bd683c295a44af8050797dc4a41376ff Mon Sep 17 00:00:00 2001
From: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>
Date: Mon, 25 Apr 2016 23:32:37 -0700
Subject: aacraid: Fix for KDUMP driver hang

From: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@microsemi.com>

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@microsemi.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/scsi/aacraid/aacraid.h  |    1 +
 drivers/scsi/aacraid/comminit.c |   24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+)

--- 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
--- 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>
@@ -47,6 +48,20 @@ 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;
@@ -425,6 +440,15 @@ struct aac_dev *aac_init_adapter(struct
 	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)) &&


Patches currently in stable-queue which might be from RaghavaAditya.Renukunta@microsemi.com are

queue-4.4/aacraid-fix-for-kdump-driver-hang.patch
queue-4.4/aacraid-fix-for-aac_command_thread-hang.patch
queue-4.4/aacraid-relinquish-cpu-during-timeout-wait.patch