releases/3.1.1/drm-radeon-kms-add-msi-module-parameter.patch

From a18cee15ed4c8b6a35f96b7b26a46bac32e04bd9 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Tue, 1 Nov 2011 14:20:30 -0400
Subject: drm/radeon/kms: add MSI module parameter

From: Alex Deucher <alexander.deucher@amd.com>

commit a18cee15ed4c8b6a35f96b7b26a46bac32e04bd9 upstream.

Allow the user to override whether MSIs are enabled
or not on supported ASICs.  MSIs are disabled by default
on IGP chips as they tend not to work.  However certain
IGP chips only seem to work with MSIs enabled.

I suspect this is a chipset or bios issue, but I'm not sure
what the proper fix is.  This will at least make diagnosing
and working around the problem much easier.

See:
https://bugs.freedesktop.org/show_bug.cgi?id=37679

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 drivers/gpu/drm/radeon/radeon.h         |    1 +
 drivers/gpu/drm/radeon/radeon_drv.c     |    4 ++++
 drivers/gpu/drm/radeon/radeon_irq_kms.c |    6 ++++++
 3 files changed, 11 insertions(+)

--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -93,6 +93,7 @@ extern int radeon_audio;
 extern int radeon_disp_priority;
 extern int radeon_hw_i2c;
 extern int radeon_pcie_gen2;
+extern int radeon_msi;
 
 /*
  * Copy from radeon_drv.h so we don't have to include both and have conflicting
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -118,6 +118,7 @@ int radeon_audio = 0;
 int radeon_disp_priority = 0;
 int radeon_hw_i2c = 0;
 int radeon_pcie_gen2 = 0;
+int radeon_msi = -1;
 
 MODULE_PARM_DESC(no_wb, "Disable AGP writeback for scratch registers");
 module_param_named(no_wb, radeon_no_wb, int, 0444);
@@ -164,6 +165,9 @@ module_param_named(hw_i2c, radeon_hw_i2c
 MODULE_PARM_DESC(pcie_gen2, "PCIE Gen2 mode (1 = enable)");
 module_param_named(pcie_gen2, radeon_pcie_gen2, int, 0444);
 
+MODULE_PARM_DESC(msi, "MSI support (1 = enable, 0 = disable, -1 = auto)");
+module_param_named(msi, radeon_msi, int, 0444);
+
 static int radeon_suspend(struct drm_device *dev, pm_message_t state)
 {
 	drm_radeon_private_t *dev_priv = dev->dev_private;
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -118,6 +118,12 @@ static bool radeon_msi_ok(struct radeon_
 	if (rdev->flags & RADEON_IS_AGP)
 		return false;
 
+	/* force MSI on */
+	if (radeon_msi == 1)
+		return true;
+	else if (radeon_msi == 0)
+		return false;
+
 	/* Quirks */
 	/* HP RS690 only seems to work with MSIs. */
 	if ((rdev->pdev->device == 0x791f) &&