From d051bbb22e9d8e87e2a5b8efb176d1bfd0f7feee Mon Sep 17 00:00:00 2001 From: Luca Barbieri Date: Sat, 16 Jan 2010 15:27:51 +0100 Subject: [PATCH] drm/nouveau: Acknowledge DMA_VTX_PROTECTION PGRAPH interrupts Currently Nouveau is unable to dismiss DMA_VTX_PROTECTION errors, which results in an infinite loop in the interrupt handler. These errors are caused both by bugs in the Gallium driver and by user-specified index buffers with out of bounds indices. By mmio-tracing the nVidia drivers, I found out how this is done. On DMA_VTX_PROTECTION, The nVidia driver reads the register 0x402000, always getting the value 4, and then writes 4 back to 0x402000. This patch adds that logic by reading 0x402000 and writing the same value back. It's unclear what should happen if the value read is not 4, and the current approach might not be the correct one. To test this, modify mesa/progs/trivial/vbo-drawrange.c, defining ELTOBJ to 1 and replacing indices with huge out of bounds integers. Without this patch, the GPU and/or kernel should lock up. With this patch, it should misrender as expected but not lock up. The errors are still logged since they are useful for development. This has been tested on NV49 and may not work on other cards. To find out how things work on other cards, run the aforementioned test using the blob with mmiotrace and grep for a read of the PGRAPH source register. Signed-off-by: Luca Barbieri Signed-off-by: Francisco Jerez Signed-off-by: Ben Skeggs --- drivers/gpu/drm/nouveau/nouveau_irq.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/nouveau/nouveau_irq.c b/drivers/gpu/drm/nouveau/nouveau_irq.c index 919a619ca7fa..3b9bad66162a 100644 --- a/drivers/gpu/drm/nouveau/nouveau_irq.c +++ b/drivers/gpu/drm/nouveau/nouveau_irq.c @@ -483,6 +483,13 @@ nouveau_pgraph_intr_error(struct drm_device *dev, uint32_t nsource) if (nsource & NV03_PGRAPH_NSOURCE_ILLEGAL_MTHD) { if (nouveau_pgraph_intr_swmthd(dev, &trap)) unhandled = 1; + } else if (nsource & NV03_PGRAPH_NSOURCE_DMA_VTX_PROTECTION) { + uint32_t v = nv_rd32(dev, 0x402000); + nv_wr32(dev, 0x402000, v); + + /* dump the error anyway for now: it's useful for + Gallium development */ + unhandled = 1; } else { unhandled = 1; } -- 2.20.1