On Thu, May 15, 2025 at 02:58:25PM +0300, Raag Jadav wrote: > On Wed, May 14, 2025 at 11:25:36PM +0200, Denis Benato wrote: > > I tested this patch on top of 6.14.6 and this patch comes with a nasty regression: s2idle resume breaks all my three GPUs, while for example the sound of a YT video resumes fine. > > > > You can see the dmesg here: https://pastebin.com/Um7bmdWi > > Thanks for the report. From logs it looks like a hotplug event is triggered > for presence detect which is disabling the slot and in turn loosing the > device on resume. The cause of it is unclear though (assuming it is not > a manual intervention). When an Endpoint transitions to D3cold, the link to the Endpoint goes down. If the Downstream Port above the Endpoint is hotplug-capable, it will see a Data Link Layer State Changed event as a side effect. If it doesn't support out-of-band presence detect, it will also see a Presence Detect Changed event as a side effect. As a workaround, graphics drivers invoke pci_ignore_hotplug() and that will cause pciehp and acpiphp to permanently ignore any hotplug events. In v6.16 there will be a new pci_hp_ignore_link_change() and pci_hp_unignore_link_change() API to tell PCI hotplug drivers that DLLSC and PDC events shall be ignored temporarily: https://git.kernel.org/pci/pci/c/2af781a9edc4 I intend to replace pci_ignore_hotplug() with this new approach, as explained here: https://lore.kernel.org/r/Z_nfuGrVh_CO7vbe@xxxxxxxxx I'm not sure though if that will help with the issue at hand. Thanks, Lukas
