Firmware transaction timeout on Pi4B

Reproduce the hang with the reported gst-launch-1.0 command on a Pi 4B running the stated Raspberry Pi OS and kernel. Read drivers/firmware/raspberrypi.c, especially rpi_firmware_transaction, then follow the logged raspberrypi clock and cpufreq call path. Done means the firmware timeout, related clock errors, and gst-launch hang no longer occur in the reported setup.

Describe the bug
"Firmware transaction timeout" message and gst-launch hang on a Pi 4B 4GB when running gst-launch-1.0 playbin uri=https://some.domain/720p25-h264-aac.m3u8

To reproduce
Boot Pi 4B with Raspberry Pi OS (without X server), then run
gst-launch-1.0 playbin uri=https://some.domain/720p25-h264-aac.m3u8
I can try to upload the m3u8 file and associated stream somewhere.
So far, this has been 100% reproducible.

Expected behaviour
No hang.

Actual behaviour
"Firmware transaction timeout" message and gst-launch hang on a Pi 4B 4GB when running
gst-launch-1.0 playbin uri=https://some.domain/720p25-h264-aac.m3u8

System
raspinfo hangs, pasting all output before the hang:

System Information
Raspberry Pi 4 Model B Rev 1.2
PRETTY_NAME="Raspbian GNU/Linux 10 (buster)"
NAME="Raspbian GNU/Linux"
VERSION_ID="10"
VERSION="10 (buster)"

Raspberry Pi reference 2020-08-20
Generated using pi-gen, https://github.com/RPi-Distro/pi-gen, 9a3a10bf1019ebb2d59053564dc6b90068bad27d, stage4

Linux pi4-nak1 5.4.79-v7l+ #1373 SMP Mon Nov 23 13:27:40 GMT 2020 armv7l GNU/Linux
Revision : b03112
Serial : 100000004ad7632c
Model : Raspberry Pi 4 Model B Rev 1.2

Logs
If applicable, add the relevant output from dmesg or similar.

[   95.340807] fuse: init (API version 7.31)
[  711.440163] ------------[ cut here ]------------
[  711.440185] WARNING: CPU: 1 PID: 31 at drivers/firmware/raspberrypi.c:63 rpi_firmware_transaction+0xec/0x128
[  711.440190] Firmware transaction timeout
[  711.440193] Modules linked in: fuse cmac rfcomm bnep hci_uart btbcm bluetooth ecdh_generic ecc xfrm4_tunnel tunnel4 ipcomp xfrm_ipcomp esp4 ah4 af_key 8021q garp stp llc spidev brcmfmac brcmutil sha256_generic libsha256 cfg80211 v3d rfkill raspberrypi_hwmon gpu_sched i2c_mux_pinctrl i2c_mux bcm2835_codec(C) i2c_bcm2835 vc4 spi_bcm2835 v4l2_mem2mem bcm2835_v4l2(C) bcm2835_isp(C) bcm2835_mmal_vchiq(C) videobuf2_vmalloc cec videobuf2_dma_contig videobuf2_memops videobuf2_v4l2 videobuf2_common drm_kms_helper videodev drm snd_bcm2835(C) mc vc_sm_cma(C) drm_panel_orientation_quirks snd_soc_core snd_compress snd_pcm_dmaengine snd_pcm snd_timer rpivid_mem snd syscopyarea sysfillrect sysimgblt fb_sys_fops uio_pdrv_genirq uio i2c_dev ip_tables x_tables ipv6
[  711.440326] CPU: 1 PID: 31 Comm: kworker/1:1 Tainted: G         C        5.4.79-v7l+ #1373
[  711.440329] Hardware name: BCM2711
[  711.440336] Workqueue: events dbs_work_handler
[  711.440340] Backtrace: 
[  711.440350] [<c020dfb0>] (dump_backtrace) from [<c020e334>] (show_stack+0x20/0x24)
[  711.440355]  r7:ffffffff r6:00000000 r5:60000013 r4:c129fab0
[  711.440363] [<c020e314>] (show_stack) from [<c0a76254>] (dump_stack+0xd8/0x11c)
[  711.440370] [<c0a7617c>] (dump_stack) from [<c0222028>] (__warn+0xe0/0x108)
[  711.440375]  r10:cfc04008 r9:00000009 r8:c08dd810 r7:0000003f r6:00000009 r5:c08dd810
[  711.440378]  r4:c0e3a554 r3:00000000
[  711.440384] [<c0221f48>] (__warn) from [<c0222424>] (warn_slowpath_fmt+0xa4/0xc0)
[  711.440389]  r7:0000003f r6:c0e3a554 r5:c1204fc8 r4:c0e3a574
[  711.440395] [<c0222384>] (warn_slowpath_fmt) from [<c08dd810>] (rpi_firmware_transaction+0xec/0x128)
[  711.440400]  r9:cee307c0 r8:00000018 r7:00000000 r6:ffffff92 r5:cee307c0 r4:c1204fc8
[  711.440407] [<c08dd724>] (rpi_firmware_transaction) from [<c08dd908>] (rpi_firmware_property_list+0xbc/0x170)
[  711.440411]  r7:c1204fc8 r6:cfc04000 r5:00001000 r4:cfc04024
[  711.440418] [<c08dd84c>] (rpi_firmware_property_list) from [<c08dda2c>] (rpi_firmware_property+0x70/0x118)
[  711.440423]  r10:ceccb8cc r9:00030002 r8:00000018 r7:cee307c0 r6:cee19d48 r5:0000000c
[  711.440426]  r4:ceccb8c0
[  711.440434] [<c08dd9bc>] (rpi_firmware_property) from [<c0733718>] (raspberrypi_clock_property+0x54/0x7c)
[  711.440439]  r10:00000000 r9:c9e57100 r8:00000001 r7:c1367c98 r6:59682f00 r5:cee19d70
[  711.440442]  r4:c1204fc8 r3:0000000c
[  711.440449] [<c07336c4>] (raspberrypi_clock_property) from [<c073378c>] (raspberrypi_fw_get_rate+0x4c/0x70)
[  711.440452]  r5:00000000 r4:c1204fc8
[  711.440460] [<c0733740>] (raspberrypi_fw_get_rate) from [<c072a19c>] (clk_recalc+0x44/0x84)
[  711.440463]  r4:cef52900
[  711.440470] [<c072a158>] (clk_recalc) from [<c072a48c>] (__clk_recalc_rates+0x30/0x94)
[  711.440474]  r5:00000000 r4:cef52900
[  711.440480] [<c072a45c>] (__clk_recalc_rates) from [<c072a55c>] (clk_core_get_rate+0x6c/0x70)
[  711.440485]  r7:c1367c98 r6:c1204fc8 r5:29b92700 r4:cef52900
[  711.440491] [<c072a4f0>] (clk_core_get_rate) from [<c072a584>] (clk_get_rate+0x24/0x28)
[  711.440495]  r5:29b92700 r4:c9e53800
[  711.440501] [<c072a560>] (clk_get_rate) from [<c08aa2ac>] (dev_pm_opp_set_rate+0x70/0x4b4)
[  711.440507] [<c08aa23c>] (dev_pm_opp_set_rate) from [<c08b4af8>] (set_target+0x3c/0x64)
[  711.440512]  r10:00000000 r9:00000000 r8:00000001 r7:c1367c98 r6:00000000 r5:000aae60
[  711.440515]  r4:c9e53c00
[  711.440521] [<c08b4abc>] (set_target) from [<c08aef18>] (__cpufreq_driver_target+0x1a8/0x51c)
[  711.440526]  r7:c1367c98 r6:00000000 r5:c1204fc8 r4:c9e53c00
[  711.440532] [<c08aed70>] (__cpufreq_driver_target) from [<c08b2b5c>] (od_dbs_update+0xc4/0x170)
[  711.440537]  r10:00000000 r9:c87af800 r8:c864fa80 r7:c87af680 r6:c87af800 r5:c87af680
[  711.440540]  r4:c9e53c00
[  711.440546] [<c08b2a98>] (od_dbs_update) from [<c08b3da8>] (dbs_work_handler+0x3c/0x64)
[  711.440551]  r9:00000040 r8:c128fb08 r7:c9e53c00 r6:c87af684 r5:00000000 r4:c87af6b8
[  711.440558] [<c08b3d6c>] (dbs_work_handler) from [<c023e884>] (process_one_work+0x250/0x570)
[  711.440563]  r9:00000040 r8:00000000 r7:dff1e600 r6:dff1b300 r5:ced68080 r4:c87af6b8
[  711.440569] [<c023e634>] (process_one_work) from [<c023ec04>] (worker_thread+0x60/0x5d0)
[  711.440574]  r10:dff1b300 r9:c1203d00 r8:dff1b318 r7:00000008 r6:dff1b300 r5:ced68094
[  711.440577]  r4:ced68080
[  711.440584] [<c023eba4>] (worker_thread) from [<c0245fd0>] (kthread+0x170/0x174)
[  711.440588]  r10:ced15e74 r9:c023eba4 r8:ced68080 r7:cee18000 r6:00000000 r5:ced63080
[  711.440592]  r4:cee1a040
[  711.440597] [<c0245e60>] (kthread) from [<c02010ac>] (ret_from_fork+0x14/0x28)
[  711.440601] Exception stack(0xcee19fb0 to 0xcee19ff8)
[  711.440606] 9fa0:                                     00000000 00000000 00000000 00000000
[  711.440610] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[  711.440614] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[  711.440619]  r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:c0245e60
[  711.440622]  r4:ced63080
[  711.440627] ---[ end trace 473967205885bfb5 ]---
[  711.440642] cpu cpu0: dev_pm_opp_set_rate: failed to find current OPP for freq 4294967186 (-34)
[  712.480177] raspberrypi-clk soc:firmware:clocks: Failed to change fw-clk-arm frequency: -110
[  714.560189] hwmon hwmon1: Failed to get throttled (-110)
[  715.600193] cpu cpu0: dev_pm_opp_set_rate: failed to find current OPP for freq 4294967186 (-34)
[  716.640198] raspberrypi-clk soc:firmware:clocks: Failed to change fw-clk-arm frequency: -110
[  724.301679] vc_sm_cma_import_dmabuf: imported vc_sm_cma_get_buffer failed -512
[  724.301686] bcm2835_mmal_vchiq: vchiq_mmal_submit_buffer: vc_sm_import_dmabuf_fd failed, ret -512
[  724.301693] bcm2835-codec bcm2835-codec: device_run: Failed submitting op buffer

Additional context
Attached devices:

• HDMI monitor
• Ethernet cable
• No USB devices, I'm accessing the Pi via SSH.