AMD Cezanne Laptops See Last Minute Suspend/Resume Fix With Linux 6.1

For those running an AMD Ryzen 5000 series "Cezanne" powered laptop, squeezing into the kernel this week ahead of the Linux 6.1 debut on Sunday is a suspend/resume fix affecting various models.

This year there have been a number of suspend-to-idle and suspend/resume fixes to enter the mainline kernel affecting a variety of AMD Ryzen laptops. This has been part of AMD's broader emphasis the past two years or so on improving their Linux client support. Now this week for Linux 6.1 is another important suspend/resume fix to land for Ryzen 5000 series SoCs.

Sent in today for Linux 6.1 -- and already merged -- was platform-drivers-x86 for 6.1-5 with the sole patch being a workaround for an s0i3 issue on some AMD systems.

The patch by AMD Linux client engineer Mario Limonciello explains:

Cezanne platforms under the right circumstances have a synchronization problem where attempting to enter s2idle may fail if the x86 cores are put into HLT before hardware resume from the previous attempt has completed.

To avoid this issue add a 10-20ms delay before entering s2idle another time. This workaround will only be applied on interrupts that wake the hardware but don't break the s2idle loop.

Yep, just adding that little bit of sleep should fix up suspend/resume for more Ryzen 5000 series laptops on Linux.

The Linux 6.1 stable kernel is expected to be released on Sunday, 11 December, with this fix alongside many other exciting features. On the AMD side with this kernel is AMD LbrExtV2 and CPU cache-to-cache and memory reporting with perf for Zen 4 CPUs, AMD IOMMU v2 page table work, the introduction of the AMD Platform Management Framework, AMD P-State fixes, continued AMD Radeon RDNA3 graphics changes, AMDGPU gang submit support needed by the RADV Vulkan driver for mesh shaders, and more.