On Sat, 2022-04-30 at 00:56 +0200, Karol Herbst wrote: > On Fri, Apr 29, 2022 at 9:54 PM Lyude Paul <lyude@xxxxxxxxxx> wrote: > > > > There's plenty of ways to fudge the GPU when developing on nouveau by > > mistake, some of which can result in nouveau seriously spamming dmesg with > > fault errors. This can be somewhat annoying, as it can quickly overrun the > > message buffer (or your terminal emulator's buffer) and get rid of > > actually > > useful feedback from the driver. While working on my new atomic only MST > > branch, I ran into this issue a couple of times. > > > > So, let's fix this by adding nvkm_error_ratelimited(), and using it to > > ratelimit errors from faults. This should be fine for developers, since > > it's nearly always only the first few faults that we care about seeing. > > Plus, you can turn off rate limiting in the kernel if you really need to. > > > > good idea :) > > Although I think we ultimately need a detection of "GPU state is > trashed" where we cease to do anything and disable interrupts as some > of those issues actually cause the kernel to get DOSed by nouveau > spamming/handling interrupts. Not sure if we should go with this patch > in the meantime, or if we should just go straight ahead and disable > interrupts, which would also stop the spam. > > Do you know if this patch here is enough to get the system to reboot > normally or is it only spamming less? I'd have to try to come up with a setup that can hit this again, although it might not be that hard - last time I hit this it was because I was programming the wrong PBN values for MST payloads into nvidia's hardware. So I can't remember for sure if I could reboot, but I do know I could actually log into the system easily and do stuff with ratelimiting applied so it's definitely better then the current situation. > > > Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx> > > --- > > drivers/gpu/drm/nouveau/include/nvkm/core/subdev.h | 2 ++ > > drivers/gpu/drm/nouveau/nvkm/subdev/bus/gf100.c | 14 +++++++------- > > drivers/gpu/drm/nouveau/nvkm/subdev/bus/nv31.c | 6 +++--- > > drivers/gpu/drm/nouveau/nvkm/subdev/bus/nv50.c | 6 +++--- > > 4 files changed, 15 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/gpu/drm/nouveau/include/nvkm/core/subdev.h > > b/drivers/gpu/drm/nouveau/include/nvkm/core/subdev.h > > index 1665738948fb..96113c8bee8c 100644 > > --- a/drivers/gpu/drm/nouveau/include/nvkm/core/subdev.h > > +++ b/drivers/gpu/drm/nouveau/include/nvkm/core/subdev.h > > @@ -62,4 +62,6 @@ void nvkm_subdev_intr(struct nvkm_subdev *); > > #define nvkm_debug(s,f,a...) nvkm_printk((s), DEBUG, info, f, ##a) > > #define nvkm_trace(s,f,a...) nvkm_printk((s), TRACE, info, f, ##a) > > #define nvkm_spam(s,f,a...) nvkm_printk((s), SPAM, dbg, f, ##a) > > + > > +#define nvkm_error_ratelimited(s,f,a...) nvkm_printk((s), ERROR, > > err_ratelimited, f, ##a) > > #endif > > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bus/gf100.c > > b/drivers/gpu/drm/nouveau/nvkm/subdev/bus/gf100.c > > index 53a6651ac225..80b5aaceeaad 100644 > > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/bus/gf100.c > > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bus/gf100.c > > @@ -35,13 +35,13 @@ gf100_bus_intr(struct nvkm_bus *bus) > > u32 addr = nvkm_rd32(device, 0x009084); > > u32 data = nvkm_rd32(device, 0x009088); > > > > - nvkm_error(subdev, > > - "MMIO %s of %08x FAULT at %06x [ %s%s%s]\n", > > - (addr & 0x00000002) ? "write" : "read", data, > > - (addr & 0x00fffffc), > > - (stat & 0x00000002) ? "!ENGINE " : "", > > - (stat & 0x00000004) ? "PRIVRING " : "", > > - (stat & 0x00000008) ? "TIMEOUT " : ""); > > + nvkm_error_ratelimited(subdev, > > + "MMIO %s of %08x FAULT at %06x [ > > %s%s%s]\n", > > + (addr & 0x00000002) ? "write" : > > "read", data, > > + (addr & 0x00fffffc), > > + (stat & 0x00000002) ? "!ENGINE " : > > "", > > + (stat & 0x00000004) ? "PRIVRING " : > > "", > > + (stat & 0x00000008) ? "TIMEOUT " : > > ""); > > > > nvkm_wr32(device, 0x009084, 0x00000000); > > nvkm_wr32(device, 0x001100, (stat & 0x0000000e)); > > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bus/nv31.c > > b/drivers/gpu/drm/nouveau/nvkm/subdev/bus/nv31.c > > index ad8da523bb22..c75e463f3501 100644 > > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/bus/nv31.c > > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bus/nv31.c > > @@ -45,9 +45,9 @@ nv31_bus_intr(struct nvkm_bus *bus) > > u32 addr = nvkm_rd32(device, 0x009084); > > u32 data = nvkm_rd32(device, 0x009088); > > > > - nvkm_error(subdev, "MMIO %s of %08x FAULT at %06x\n", > > - (addr & 0x00000002) ? "write" : "read", data, > > - (addr & 0x00fffffc)); > > + nvkm_error_ratelimited(subdev, "MMIO %s of %08x FAULT at > > %06x\n", > > + (addr & 0x00000002) ? "write" : > > "read", data, > > + (addr & 0x00fffffc)); > > > > stat &= ~0x00000008; > > nvkm_wr32(device, 0x001100, 0x00000008); > > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bus/nv50.c > > b/drivers/gpu/drm/nouveau/nvkm/subdev/bus/nv50.c > > index 3a1e45adeedc..2055d0b100d3 100644 > > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/bus/nv50.c > > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bus/nv50.c > > @@ -60,9 +60,9 @@ nv50_bus_intr(struct nvkm_bus *bus) > > u32 addr = nvkm_rd32(device, 0x009084); > > u32 data = nvkm_rd32(device, 0x009088); > > > > - nvkm_error(subdev, "MMIO %s of %08x FAULT at %06x\n", > > - (addr & 0x00000002) ? "write" : "read", data, > > - (addr & 0x00fffffc)); > > + nvkm_error_ratelimited(subdev, "MMIO %s of %08x FAULT at > > %06x\n", > > + (addr & 0x00000002) ? "write" : > > "read", data, > > + (addr & 0x00fffffc)); > > > > stat &= ~0x00000008; > > nvkm_wr32(device, 0x001100, 0x00000008); > > -- > > 2.35.1 > > > -- Cheers, Lyude Paul (she/her) Software Engineer at Red Hat
