On Fri, Aug 1, 2025 at 2:11 AM Philipp Zabel <philipp.za...@gmail.com> wrote: > > On Thu, Jul 31, 2025 at 9:38 PM Alex Deucher <alexdeuc...@gmail.com> wrote: >> >> On Thu, Jul 31, 2025 at 3:33 AM Philipp Zabel <philipp.za...@gmail.com> >> wrote: >> > >> > Don't wake the GPU if libdrm queries the mmGB_ADDR_CONFIG register >> > value during amdgpu_query_gpu_info_init(). Instead, return the already >> > cached value adev->gfx.config.gb_addr_config. >> > >> > Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2295 >> > Signed-off-by: Philipp Zabel <philipp.za...@gmail.com> >> > --- >> > drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 10 ++++++++++ >> > 1 file changed, 10 insertions(+) >> > >> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c >> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c >> > index fe1347a4075c4..ed4d7d72f2065 100644 >> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c >> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c >> > @@ -883,6 +883,16 @@ int amdgpu_info_ioctl(struct drm_device *dev, void >> > *data, struct drm_file *filp) >> > >> > alloc_size = info->read_mmr_reg.count * sizeof(*regs); >> > >> > + if (info->read_mmr_reg.dword_offset == 0x263e && >> >> I think the offset of this register varies across chip families. >> You'll need some way to determine what the offset is for each family. > > > Thank you. This workaround was specifically intended for the following call > in libdrm [1]: > > r = amdgpu_read_mm_registers(dev, 0x263e, 1, 0xffffffff, 0, > &dev->info.gb_addr_cfg); > > [1] > https://gitlab.freedesktop.org/mesa/libdrm/-/blob/9ea8a8e93d542fe61d82716d1a721e8d1d257405/amdgpu/amdgpu_gpu_info.c#L215-216 > > which also seem to hard-code the dword_offset? > > The same is now copied into Mesa [2] as: > > r = ac_drm_read_mm_registers(dev, 0x263e, 1, 0xffffffff, 0, > &info->gb_addr_cfg); > > [2] > https://gitlab.freedesktop.org/mesa/mesa/-/blob/c64c6a0c31f9cb1339bc700d236932171f7444a3/src/amd/common/ac_linux_drm.c#L722
Nevermind, it's at the same absolute offset on all chips right now. The relative offsets are just different. Alex
