drm/radeon/kms: add MSI module parameter

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>

diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index c1e056b35b292b76bdae1416cf5c95280dacb301..184628c7e02b09e2d45f84eb425084eef5e2e8cf 100644 (file)
--- 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

diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index e71d2ed7fa113126e7cacb06b1553f8767b948e6..c12b0775d688cc148bdec2f3fc72f384b2bf7add 100644 (file)
--- 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, int, 0444);
 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;

diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c
index a68c626652c7660dd39b6de9ca0479bbb6b12132..fecc1aae38289e5521c0c4c6588304e1ef6b8d29 100644 (file)
--- 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_device *rdev)
        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) &&