On Mon, Aug 31, 2020 at 7:30 AM Ben Skeggs skeggsb@gmail.com wrote:

On Tue, 25 Aug 2020 at 17:21, Alexander Kapshuk alexander.kapshuk@gmail.com wrote:

...

Since upgrading to linux-next based on 5.9.0-rc1 and 5.9.0-rc2 I have had my mouse pointer disappear soon after logging in, and I have observed the system freezing temporarily when clicking on objects and when typing text. I have also found records of push buffer errors in dmesg output: [ 6625.450394] nouveau 0000:01:00.0: disp: ERROR 1 [PUSHBUFFER_ERR] 02 [] chid 0 mthd 0000 data 00000400

Hey,

Yeah, I'm aware of this. Lyude and I have both seen it, but it's been very painful to track down to what's actually causing it so far. It likely is the commit you mentioned that's at fault, and I'm still working to find a proper solution before I revert it.

Ben.

...

I tried setting CONFIG_NOUVEAU_DEBUG=5 (tracing) to try and collect further debug info, but nothing caught the eye.

The error message in question comes from nv50_disp_intr_error in drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.c:613,645. And nv50_disp_intr_error is called from nv50_disp_intr in the following while block: drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.c:647,658 void nv50_disp_intr(struct nv50_disp *disp) { struct nvkm_device *device = disp->base.engine.subdev.device; u32 intr0 = nvkm_rd32(device, 0x610020); u32 intr1 = nvkm_rd32(device, 0x610024);

    while (intr0 & 0x001f0000) {
            u32 chid = __ffs(intr0 & 0x001f0000) - 16;
            nv50_disp_intr_error(disp, chid);
            intr0 &= ~(0x00010000 << chid);
    }

... }

Could this be in any way related to this series of commits? commit 0a96099691c8cd1ac0744ef30b6846869dc2b566 Author: Ben Skeggs bskeggs@redhat.com Date: Tue Jul 21 11:34:07 2020 +1000

drm/nouveau/kms/nv50-: implement proper push buffer control logic

We had a, what was supposed to be temporary, hack in the KMS code where we'd
completely drain an EVO/NVD channel's push buffer when wrapping to the start
again, instead of treating it as a ring buffer.

Let's fix that, finally.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Here are my GPU details: 01:00.0 VGA compatible controller: NVIDIA Corporation GT216 [GeForce 210] (rev a1) Subsystem: Micro-Star International Co., Ltd. [MSI] Device 8a93 Kernel driver in use: nouveau

The last linux-next kernel I built where the problem reported does not manifest itself is 5.8.0-rc6-next-20200720.

I would appreciate being given any pointers on how to further debug this. Or is git bisect the only way to proceed with this?

Thanks. _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel

Thanks a lot for getting back to me about this. Please let me know if there's anything else I can do to help track this down.

Alexander.