On Hirsute 5.11 the display comes up but the kernel is not happy:
$ sudo dmesg | grep -P 'firmware|WARN' [ 0.124340] raspberrypi-firmware soc:firmware: Attached to firmware from 2021-02-25T12:10:40, variant start [ 0.128359] raspberrypi-firmware soc:firmware: Firmware hash is 564e5f9b852b23a330b1764bcf0b2d022a20afd0 [ 17.517350] raspberrypi-firmware soc:firmware: Request 0x00030066 returned status 0x80000001 [ 17.530301] vc4-drm gpu: [drm] Couldn't stop firmware display driver: -22 [ 17.674616] raspberrypi-firmware soc:firmware: Request 0x00030066 returned status 0x80000001 [ 17.685979] vc4-drm gpu: [drm] Couldn't stop firmware display driver: -22 [ 17.864574] raspberrypi-firmware soc:firmware: Request 0x00030066 returned status 0x80000001 [ 17.873532] vc4-drm gpu: [drm] Couldn't stop firmware display driver: -22 [ 20.031174] raspberrypi-firmware soc:firmware: Request 0x00030066 returned status 0x80000001 [ 20.040515] vc4-drm gpu: [drm] Couldn't stop firmware display driver: -22 [ 20.127052] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:445 vc4_hdmi_encoder_post_crtc_disable+0x390/0x49c [vc4] [ 20.493554] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:417 vc4_hdmi_read+0xd8/0x140 [vc4] [ 20.803013] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:445 vc4_hdmi_encoder_post_crtc_disable+0x388/0x49c [vc4] [ 21.113145] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:417 vc4_hdmi_read+0xd8/0x140 [vc4] [ 21.422741] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:445 vc4_hdmi_encoder_post_crtc_disable+0x380/0x49c [vc4] [ 21.731941] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:417 vc4_hdmi_read+0xd8/0x140 [vc4] [ 22.041559] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:445 vc4_hdmi_encoder_post_crtc_disable+0x424/0x49c [vc4] [ 22.351113] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:417 vc4_hdmi_read+0xd8/0x140 [vc4] [ 22.662902] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:445 vc4_hdmi_encoder_post_crtc_powerdown+0x178/0x1c0 [vc4] [ 22.978912] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:445 vc5_hdmi_phy_disable+0x198/0x220 [vc4] [ 23.300587] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:445 vc5_hdmi_phy_disable+0x190/0x220 [vc4] [ 23.619497] WARNING: CPU: 1 PID: 103 at drivers/gpu/drm/vc4/vc4_hdmi_regs.h:417 vc4_hdmi_read+0xd8/0x140 [vc4]
On Hirsute 5.11 the display comes up but the kernel is not happy:
$ sudo dmesg | grep -P 'firmware|WARN' firmware soc:firmware: Attached to firmware from 2021-02- 25T12:10: 40, variant start firmware soc:firmware: Firmware hash is 564e5f9b852b23a 330b1764bcf0b2d 022a20afd0 firmware soc:firmware: Request 0x00030066 returned status 0x80000001 firmware soc:firmware: Request 0x00030066 returned status 0x80000001 firmware soc:firmware: Request 0x00030066 returned status 0x80000001 firmware soc:firmware: Request 0x00030066 returned status 0x80000001 gpu/drm/ vc4/vc4_ hdmi_regs. h:445 vc4_hdmi_ encoder_ post_crtc_ disable+ 0x390/0x49c [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:417 vc4_hdmi_ read+0xd8/ 0x140 [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:445 vc4_hdmi_ encoder_ post_crtc_ disable+ 0x388/0x49c [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:417 vc4_hdmi_ read+0xd8/ 0x140 [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:445 vc4_hdmi_ encoder_ post_crtc_ disable+ 0x380/0x49c [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:417 vc4_hdmi_ read+0xd8/ 0x140 [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:445 vc4_hdmi_ encoder_ post_crtc_ disable+ 0x424/0x49c [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:417 vc4_hdmi_ read+0xd8/ 0x140 [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:445 vc4_hdmi_ encoder_ post_crtc_ powerdown+ 0x178/0x1c0 [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:445 vc5_hdmi_ phy_disable+ 0x198/0x220 [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:445 vc5_hdmi_ phy_disable+ 0x190/0x220 [vc4] gpu/drm/ vc4/vc4_ hdmi_regs. h:417 vc4_hdmi_ read+0xd8/ 0x140 [vc4]
[ 0.124340] raspberrypi-
[ 0.128359] raspberrypi-
[ 17.517350] raspberrypi-
[ 17.530301] vc4-drm gpu: [drm] Couldn't stop firmware display driver: -22
[ 17.674616] raspberrypi-
[ 17.685979] vc4-drm gpu: [drm] Couldn't stop firmware display driver: -22
[ 17.864574] raspberrypi-
[ 17.873532] vc4-drm gpu: [drm] Couldn't stop firmware display driver: -22
[ 20.031174] raspberrypi-
[ 20.040515] vc4-drm gpu: [drm] Couldn't stop firmware display driver: -22
[ 20.127052] WARNING: CPU: 1 PID: 103 at drivers/
[ 20.493554] WARNING: CPU: 1 PID: 103 at drivers/
[ 20.803013] WARNING: CPU: 1 PID: 103 at drivers/
[ 21.113145] WARNING: CPU: 1 PID: 103 at drivers/
[ 21.422741] WARNING: CPU: 1 PID: 103 at drivers/
[ 21.731941] WARNING: CPU: 1 PID: 103 at drivers/
[ 22.041559] WARNING: CPU: 1 PID: 103 at drivers/
[ 22.351113] WARNING: CPU: 1 PID: 103 at drivers/
[ 22.662902] WARNING: CPU: 1 PID: 103 at drivers/
[ 22.978912] WARNING: CPU: 1 PID: 103 at drivers/
[ 23.300587] WARNING: CPU: 1 PID: 103 at drivers/
[ 23.619497] WARNING: CPU: 1 PID: 103 at drivers/