[v2,2/2] drm/amdgpu: fix bad DMA from INTERRUPT_CNTL2
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Message ID d7554ed7f29a5b792cfab8af5d5131271927a952.1574034832.git.sbobroff@linux.ibm.com
State New
Headers show
Series
  • fix bad DMA from INTERRUPT_CNTL2
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Commit Message

Sam Bobroff Nov. 17, 2019, 11:53 p.m. UTC
The INTERRUPT_CNTL2 register expects a valid DMA address, but is
currently set with a GPU MC address.  This can cause problems on
systems that detect the resulting DMA read from an invalid address
(found on a Power8 guest).

Instead, use the DMA address of the dummy page because it will always
be safe.

Fixes: 27ae10641e9c ("drm/amdgpu: add interupt handler implementation for si v3")
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
---
v2 * New in this version.

 drivers/gpu/drm/amd/amdgpu/si_ih.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch
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diff --git a/drivers/gpu/drm/amd/amdgpu/si_ih.c b/drivers/gpu/drm/amd/amdgpu/si_ih.c
index 57bb5f9e08b2..88ae27a5a03d 100644
--- a/drivers/gpu/drm/amd/amdgpu/si_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/si_ih.c
@@ -64,7 +64,8 @@  static int si_ih_irq_init(struct amdgpu_device *adev)
 	u32 interrupt_cntl, ih_cntl, ih_rb_cntl;
 
 	si_ih_disable_interrupts(adev);
-	WREG32(INTERRUPT_CNTL2, adev->irq.ih.gpu_addr >> 8);
+	/* set dummy read address to dummy page address */
+	WREG32(INTERRUPT_CNTL2, adev->dummy_page_addr >> 8);
 	interrupt_cntl = RREG32(INTERRUPT_CNTL);
 	interrupt_cntl &= ~IH_DUMMY_RD_OVERRIDE;
 	interrupt_cntl &= ~IH_REQ_NONSNOOP_EN;