search for: sg_debug

On Fri, 2024-04-26 at 11:41 -0400, Lyude Paul wrote: > We hit this because when initializing firmware of type > NVKM_FIRMWARE_IMG_DMA we allocate coherent memory and then attempt to > include that coherent memory in a scatterlist. I'm sure this patch is a good one, and I will try to test it soon, but I am very curious to know why including coherent memory in a scatterlist is bad.

On Fri, 2024-04-26 at 15:47 +0000, Timur Tabi wrote: > On Fri, 2024-04-26 at 11:41 -0400, Lyude Paul wrote: > > We hit this because when initializing firmware of type > > NVKM_FIRMWARE_IMG_DMA we allocate coherent memory and then attempt > > to > > include that coherent memory in a scatterlist. > > I'm sure this patch is a good one, and I will try to test it

Currently, enabling SG_DEBUG in the kernel will cause nouveau to hit a BUG() on startup: kernel BUG at include/linux/scatterlist.h:187! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 7 PID: 930 Comm: (udev-worker) Not tainted 6.9.0-rc3Lyude-Test+ #30 Hardware name: MSI MS-7A39/A320M GAMING PRO (MS-7A39), BIOS 1.I0 0...

...; [ 0.484470] nouveau 0000:01:00.0: DRM-master: Device allocation failed: -5 > [ 0.485078] nouveau 0000:01:00.0: probe with driver nouveau failed with error -50 > > I bisected between v6.9-rc6 and v6.9-rc7 and that identified commit > 52a6947bf576 ("drm/nouveau/firmware: Fix SG_DEBUG error with > nvkm_firmware_ctor()") as the first bad commit. Lyude, that's a commit of yours. Given that 6.9 is due a quick question: I assume there is no easy fix for this in sight? Or is a quick revert something that might be appropriate to prevent this from entering 6.9? Ciao, Tho...