Thinkpad T495s Ryzen, kubuntu 20.04: a tela só funciona no modo de recuperação

Thinkpad T495s Ryzen, kubuntu 20.04: a tela só funciona no modo de recuperação

Acabei de fazer uma nova instalação do kubuntu 20.04 em um novo thinkpad 495s.

A tela de login (gráfica) parece normal, exceto que falta o ponteiro do mouse. Após o login, no entanto, tenho uma tela quase toda preta/acinzentada. Ao iniciar um console (usando ctrl-alt-t), posso adivinhar pelo cinza que ele está lá, apenas para poder digitar sudo shutdown now.

No entanto, se eu inicializar usando o modo de recuperação, o computador estará quase utilizável, exceto que não consigo controlar a luz de fundo da tela: pressionar fn-F5faz com que a janela de controle da luz de fundo apareça, mostrando que a luz de fundo deve ser diminuída, mas nada realmente acontece.

EDIT: aparentemente, tanto a tela quanto a luz de fundo funcionam se eu inicializar com a energia conectada.

Não sei se esses dois problemas estão relacionados entre si.

martin@toolbox:~$ uname -r
5.4.0-45-generic

martin@toolbox:~$ lspci
00:00.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 Root Complex
00:00.2 IOMMU: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 IOMMU
00:01.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:01.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 PCIe GPP Bridge [6:0]
00:01.3 PCI bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 PCIe GPP Bridge [6:0]
00:01.4 PCI bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 PCIe GPP Bridge [6:0]
00:01.7 PCI bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 PCIe GPP Bridge [6:0]
00:08.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-1fh) PCIe Dummy Host Bridge
00:08.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 Internal PCIe GPP Bridge 0 to Bus A
00:14.0 SMBus: Advanced Micro Devices, Inc. [AMD] FCH SMBus Controller (rev 61)
00:14.3 ISA bridge: Advanced Micro Devices, Inc. [AMD] FCH LPC Bridge (rev 51)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 Device 24: Function 0
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 Device 24: Function 1
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 Device 24: Function 2
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 Device 24: Function 3
00:18.4 Host bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 Device 24: Function 4
00:18.5 Host bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 Device 24: Function 5
00:18.6 Host bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 Device 24: Function 6
00:18.7 Host bridge: Advanced Micro Devices, Inc. [AMD] Raven/Raven2 Device 24: Function 7
01:00.0 Network controller: Intel Corporation Wireless-AC 9260 (rev 29)
02:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0e)
03:00.1 Serial controller: Realtek Semiconductor Co., Ltd. Device 816a (rev 0e)
03:00.2 Serial controller: Realtek Semiconductor Co., Ltd. Device 816b (rev 0e)
03:00.3 IPMI Interface: Realtek Semiconductor Co., Ltd. Device 816c (rev 0e)
03:00.4 USB controller: Realtek Semiconductor Co., Ltd. Device 816d (rev 0e)
04:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS522A PCI Express Card Reader (rev 01)
05:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Picasso (rev d2)
05:00.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Raven/Raven2/Fenghuang HDMI/DP Audio Controller
05:00.2 Encryption controller: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 10h-1fh) Platform Security Processor
05:00.3 USB controller: Advanced Micro Devices, Inc. [AMD] Raven USB 3.1
05:00.4 USB controller: Advanced Micro Devices, Inc. [AMD] Raven USB 3.1
05:00.5 Multimedia controller: Advanced Micro Devices, Inc. [AMD] Raven/Raven2/FireFlight/Renoir Audio Processor
05:00.6 Audio device: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 10h-1fh) HD Audio Controller

Responder1

você tentou a opção de inicialização "iommu=soft" conforme descrito aqui:

https://www.reddit.com/r/thinkpad/comments/eb08hk/t495_unplugged_battery_broken_boot_with_linux/

Talvez isso resolva o seu problema também...

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