Context

See hibernate-pocket, hibernate-pocket-2, hibernate-pocket-3, hibernate-pocket-4,hibernate-pocket-5, hibernate-pocket-6, hibernate-pocket-7, hibernate-pocket-8, hibernate-pocket-9 hibernate-pocket-10 hibernate-pocket-11 hibernate-pocket-12

Some progress upstream

Recently Sebastian Reichel at Collabora [1] has made a few related commits, apparently inspired in part by my kvetching on this blog.

Disconnecting and reconnecting PCI busses

At some point I noticed error message about the nvme device on resume. I then learned how to disconnect and reconnect PCI buses in Linux. I ended up with something like the following. At least the PCI management seems to work. I can manually disconnect all the PCI busses and rescan to connect them again on a running system. It presumably helps that I am not using the nvme device in this system.

set -x
echo platform >  /sys/power/pm_test
echo reboot > /sys/power/disk
rmmod mt76x2u
sleep 2
echo 1 | tee /sys/bus/pci/devices/0003:30:00.0/remove
sleep 2
echo 1 | tee /sys/bus/pci/devices/0004:41:00.0/remove
sleep 2
echo 1 | tee /sys/bus/pci/devices/0004:40:00.0/remove
sleep 2
echo LSPCI:
lspci -t
sleep 2
echo disk >  /sys/power/state
sleep 2
echo 1 | tee /sys/bus/pci/rescan
sleep 2
modprobe mt76x2u

Minimal changes to upstream

With the ongoing work at collabora I decided to try a minimal patch stack to get the pocket reform to boot. I added the following 3 commits (available from [3]).

09868a4f2eb (HEAD -> reform-patches) copy pocket-reform dts from reform-debian-packages
152e2ae8a193 pocket/panel: sleep fix v3
18f65da9681c add-multi-display-panel-driver

It does indeed boot and seems stable.

$ uname -a
Linux anthia 6.18.0-rc1+ #19 SMP Thu Oct 16 11:32:04 ADT 2025 aarch64 GNU/Linux

Running the hibernation script above I get no output from the lspci, but seemingly issues with PCI coming back from hibernate:

[  424.645109] PM: hibernation: Allocated 361823 pages for snapshot
[  424.647216] PM: hibernation: Allocated 1447292 kbytes in 3.23 seconds (448.07 MB/s)
[  424.649321] Freezing remaining freezable tasks
[  424.654767] Freezing remaining freezable tasks completed (elapsed 0.003 seconds)
[  424.661070] rk_gmac-dwmac fe1b0000.ethernet end0: Link is Down
[  424.740716] rockchip-dw-pcie a40c00000.pcie: Failed to receive PME_TO_Ack
[  424.742041] PM: hibernation: hibernation debug: Waiting for 5 second(s).
[  430.074757] pci 0004:40:00.0: [1d87:3588] type 01 class 0x060400 PCIe Root Port
F�F���&�Zn�[� watchdog: CPU4: Watchdog detected hard LOCKUP on cpu 5
[  456.039004] Modules linked in: xt_CHECKSUM xt_tcpudp nft_chain_nat xt_MASQUERADE nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat x_tables bridge stp llc nf_tables aes_neon_bs aes_neon_blk ccm dwmac_rk binfmt_misc mt76x2_common mt76x02_usb mt76_usb mt76x02_lib mt76 mac80211 rk805_pwrkey snd_soc_tlv320aic31xx snd_soc_simple_card reform2_lpc(OE) libarc4 rockchip_saradc industrialio_triggered_buffer kfifo_buf industrialio cfg80211 rockchip_thermal rockchip_rng hantro_vpu cdc_acm v4l2_vp9 v4l2_jpeg rockchip_rga rfkill snd_soc_rockchip_i2s_tdm videobuf2_dma_sg v4l2_h264 panthor snd_soc_audio_graph_card drm_gpuvm snd_soc_simple_card_utils drm_exec evdev joydev dm_mod nvme_fabrics efi_pstore configfs nfnetlink autofs4 ext4 crc16 mbcache jbd2 btrfs blake2b_generic xor xor_neon raid6_pq mali_dp snd_soc_meson_axg_toddr snd_soc_meson_axg_fifo snd_soc_meson_codec_glue panfrost drm_shmem_helper gpu_sched ao_cec_g12a meson_vdec(C) videobuf2_dma_contig videobuf2_memops v4l2_mem2mem videobuf2_v4l2 videodev
[  456.039060]  videobuf2_common mc dw_hdmi_i2s_audio meson_drm meson_canvas meson_dw_mipi_dsi meson_dw_hdmi mxsfb mux_mmio panel_edp imx_dcss ti_sn65dsi86 nwl_dsi mux_core pwm_imx27 hid_generic usbhid hid xhci_plat_hcd onboard_usb_dev xhci_hcd nvme nvme_core snd_soc_hdmi_codec snd_soc_core nvme_keyring nvme_auth hkdf snd_pcm_dmaengine snd_pcm snd_timer snd soundcore fan53555 rtc_pcf8523 micrel phy_package stmmac_platform stmmac pcs_xpcs rk808_regulator phylink sdhci_of_dwcmshc mdio_devres dw_mmc_rockchip of_mdio sdhci_pltfm phy_rockchip_usbdp fixed_phy dw_mmc_pltfm fwnode_mdio typec phy_rockchip_naneng_combphy phy_rockchip_samsung_hdptx pwm_rockchip sdhci dwc3 libphy dw_wdt dw_mmc ehci_platform rockchip_dfi mdio_bus cqhci ulpi ohci_platform ehci_hcd udc_core ohci_hcd rockchipdrm phy_rockchip_inno_usb2 usbcore dw_hdmi_qp analogix_dp dw_mipi_dsi cpufreq_dt dw_mipi_dsi2 i2c_rk3x usb_common drm_dp_aux_bus [last unloaded: mt76x2u]
[  456.039111] Sending NMI from CPU 4 to CPUs 5:
[  471.942262] page_pool_release_retry() stalled pool shutdown: id 9, 2 inflight 60 sec
[  532.989611] page_pool_release_retry() stalled pool shutdown: id 9, 2 inflight 121 sec

This does look like some progress, probably thanks to Sebastien. Comparing with the logs in hibernate-pocket-12, the resume process is not bailing out complaining about PHY.

Attempt to reapply PCI reset patches

Following the procedure in hibernate-pocket-12, I attempted to re-apply the pci reset patches [2]. In particular I followed the hints output by b4.

Unfortunately there are too many conflicts now for me to sensibly resolve.

https://gitlab.collabora.com/hardware-enablement/rockchip-3588/linux.git#rockchip-devel
https://lore.kernel.org/all/20250715-pci-port-reset-v6-0-6f9cce94e7bb@oss.qualcomm.com/#r
https://salsa.debian.org/bremner/collabora-rockchip-3588#reform-patches