** Description changed: [ Impact ] The amdgpu probing sequence can fail for any multitude of reasons (missing firmware, missing NPI support, unexpected hardware response). Ideally; we would have all NPI support in Ubuntu at product launch, but due to kernel schedule this isn't always feasible; particularly for dGPUs. For missing NPI support on dGPU specifically we want to be able to identify the system though so that we can potentially offer DKMS package from amdgpu-install script. To support this need there are changes introduced that will export IP discovery information to userspace even during probe failure. [ Fix ] The major patchsets are: 1. drm/amdgpu: Export ip_discovery sysfs on probe failure[1]: in linux-next 402e04f11ff7 2. drm/amdgpu: clean up discovery and preempt sysfs entries on shutdown[2]: in linux-next 7de02fe95312 3. drm/amdgpu: don't free standalone ip_discovery sysfs in sysfs_fini[3]: in linux-next 26373c719455 And their dependent patches. See additional information. [ Test plan ] On APU/dGPU already supported by Ubuntu out-of-the-box: 1) Remove a GPU firmware from /lib/firmware. 2) Reboot system 3) Verify amdgpu shows probe error 4) Verify that IP discovery info in sysfs 5) Unload amdgpu 6) Restore GPU firmware 7) reload amdgpu 8) Verify works On new APU/dGPU 1) Verify amdgpu shows probe error 2) Verify that IP discovery info in sysfs [ Where problems could occur] - This changes amdgpu module load/unload behaviors, and internal - implementation of some of its sysfs files. Bugs in those implementation - may impact tools actively reading those sysfs files (likely, various - AMD's own tools), or load/unload amdgpu module. + This changes + + Bug in this likely leads to 1) handling of probe failure and 2) module + unload/reload behavior and 3) internal implementation of sysfs files + under ip_discovery. + + For 1), if a probe fails then the gpu drivers is already in the bad + state. This at least leave more postmoterm information that we can + revisit. + + For 2), use cases that need active unload/load the module when system is + up and running may be impacted, which is likely rare. + + For 3), tools relying on those sysfs files may be impacted. [ Additional information ] [1] https://lore.kernel.org/amd-gfx/[email protected]/ [2] https://lore.kernel.org/amd-gfx/[email protected]/ [3] https://lore.kernel.org/amd-gfx/[email protected]/ The full patch list to support this on 7.0-based kernel: ``` drm/amdgpu: don't free standalone ip_discovery sysfs in sysfs_fini drm/amdgpu: clean up discovery and preempt sysfs entries on shutdown drm/amdgpu: Export ip_discovery sysfs on probe failure drm/amdgpu: Fix discovery offset check under VF drm/amdgpu: fix IP discovery v0 handling drm/amdgpu: Add size guard before copy discovery binary - drm/amdgpu: use DISCOVERY_TMR_SIZE in ACPI TMR fallback + drm/amdgpu: use DISCOVERY_TMR_SIZE in ACPI TMR fallback drm/amdgpu: Avoid NULL dereference in discovery topology coredump path v3 drm/amdgpu: fallback to default discovery offset/size in sriov guest drm/amdgpu: New interface to get IP discovery binary v3 drm/amdgpu/discovery: use common function to check discovery table drm/amdgpu/discovery: support new discovery binary header drm/amdgpu: include ip discovery data in devcoredump ```
** Description changed: + BugLink: https://bugs.launchpad.net/bugs/2158690 + [ Impact ] The amdgpu probing sequence can fail for any multitude of reasons (missing firmware, missing NPI support, unexpected hardware response). Ideally; we would have all NPI support in Ubuntu at product launch, but due to kernel schedule this isn't always feasible; particularly for dGPUs. For missing NPI support on dGPU specifically we want to be able to identify the system though so that we can potentially offer DKMS package from amdgpu-install script. To support this need there are changes introduced that will export IP discovery information to userspace even during probe failure. [ Fix ] The major patchsets are: 1. drm/amdgpu: Export ip_discovery sysfs on probe failure[1]: in linux-next 402e04f11ff7 2. drm/amdgpu: clean up discovery and preempt sysfs entries on shutdown[2]: in linux-next 7de02fe95312 3. drm/amdgpu: don't free standalone ip_discovery sysfs in sysfs_fini[3]: in linux-next 26373c719455 And their dependent patches. See additional information. [ Test plan ] On APU/dGPU already supported by Ubuntu out-of-the-box: 1) Remove a GPU firmware from /lib/firmware. 2) Reboot system 3) Verify amdgpu shows probe error 4) Verify that IP discovery info in sysfs 5) Unload amdgpu 6) Restore GPU firmware 7) reload amdgpu 8) Verify works On new APU/dGPU 1) Verify amdgpu shows probe error 2) Verify that IP discovery info in sysfs [ Where problems could occur] This changes Bug in this likely leads to 1) handling of probe failure and 2) module unload/reload behavior and 3) internal implementation of sysfs files under ip_discovery. For 1), if a probe fails then the gpu drivers is already in the bad state. This at least leave more postmoterm information that we can revisit. For 2), use cases that need active unload/load the module when system is up and running may be impacted, which is likely rare. For 3), tools relying on those sysfs files may be impacted. [ Additional information ] [1] https://lore.kernel.org/amd-gfx/[email protected]/ [2] https://lore.kernel.org/amd-gfx/[email protected]/ [3] https://lore.kernel.org/amd-gfx/[email protected]/ The full patch list to support this on 7.0-based kernel: ``` drm/amdgpu: don't free standalone ip_discovery sysfs in sysfs_fini drm/amdgpu: clean up discovery and preempt sysfs entries on shutdown drm/amdgpu: Export ip_discovery sysfs on probe failure drm/amdgpu: Fix discovery offset check under VF drm/amdgpu: fix IP discovery v0 handling drm/amdgpu: Add size guard before copy discovery binary drm/amdgpu: use DISCOVERY_TMR_SIZE in ACPI TMR fallback drm/amdgpu: Avoid NULL dereference in discovery topology coredump path v3 drm/amdgpu: fallback to default discovery offset/size in sriov guest drm/amdgpu: New interface to get IP discovery binary v3 drm/amdgpu/discovery: use common function to check discovery table drm/amdgpu/discovery: support new discovery binary header drm/amdgpu: include ip discovery data in devcoredump ``` -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2158690 Title: [SRU] Export IP discovery even if amdgpu probe fails To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2158690/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
