<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - WARNING: CPU: 0 PID: 487 at drivers/gpu/drm/amd/amdgpu/../display /dc/gpio/gpio_base.c:64 dal_gpio_open_ex+0xc/0x30 [amdgpu]" href="https://bugs.freedesktop.org/show_bug.cgi?id=105725#c8">Comment # 8</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - WARNING: CPU: 0 PID: 487 at drivers/gpu/drm/amd/amdgpu/../display /dc/gpio/gpio_base.c:64 dal_gpio_open_ex+0xc/0x30 [amdgpu]" href="https://bugs.freedesktop.org/show_bug.cgi?id=105725">bug 105725</a> from <a class="email" href="mailto:marc@dragonfly.plus.com" title="Marc Thomas <marc@dragonfly.plus.com>"> Marc Thomas</a> <pre>After some testing/experimentation/and scouring the internet, I've found that blacklisting modules gpio_amdpt (gpio-amdpt.ko) & pinctrl_amd (pinctrl-amd.ko) greatly reduce the likelihood of the gpio_base.c:64 & gpio_service.c:488 dmesg warnings. I suspect some kind of race condition during boot as the modules may load in any order. In Slackware-current I think pinctrl_amd was compiled in, so I had to change the Kernel config and re-compile: -CONFIG_PINCTRL_AMD=y +CONFIG_PINCTRL_AMD=m The blacklist was achieved by creating this file: root@deepthought:~# cat /etc/modprobe.d/gpio_amdpt.conf blacklist gpio_amdpt blacklist pinctrl_amd NB: I found that once I'd had these kernel warnings I needed to reset the hardware (front panel reset button or power cycle) to clear them, even with the blacklist in place. A reboot didn't seem to be enough. Finally, I do still get this warning (in 4.18-rc6 & 4.17.10), but I think the cause is something else: root@deepthought:~# dmesg | grep WARNING [ 9.260098] WARNING: CPU: 15 PID: 1138 at drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_mst_types.c:88 dm_dp_aux_transfer+0xa5/0xb0 [amdgpu] [ 9.260163] WARNING: CPU: 4 PID: 1142 at drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_mst_types.c:88 dm_dp_aux_transfer+0xa5/0xb0 [amdgpu]</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>