Re: Kernel changes causing AMDGPU / DRM to fail? i2c related?

On Mon, 31 Jan 2022 17:02:30 +0100 Tijl Coosemans <tijl@FreeBSD.org>
wrote:
> On Sun, 30 Jan 2022 21:23:49 +0300 Vladimir Kondratyev
> <wulf@FreeBSD.org> wrote:
>> On 30.01.2022 00:25, Stefan Esser wrote:
>>> After rebooting with freshly built world, kernel and the amdgpu driver
>>> my console stopped working. It goes blank and the display goes into a
>>> power save mode, as soon as the amdgpu driver is loaded.
>>> 
>>> The GPU (a Radeon R7 250E) is correctly detected as before, but there
>>> is an error message "drmn0: [drm] Cannot find any crtc or sizes".
>>> 
>>> I'm asking here and not on the ports list, since the AMDGPU driver has
>>> not been updated for half a year. But to be sure that there is no mismatch
>>> between kernel and user land, I have rebuilt all X11 server and library
>>> ports.
>>> 
>>> There have been changes affecting the i2c driver, IIRC, and the error
>>> message seems to point at an issue obtaining information from the LCD
>>> display.
>> 
>> drm-kmod commit 534aa199c10d forced it to use i2c from base.
>> 
>> You may try to checkout previous revision (444dc58f0247) to find out
>> if in-base i2c is guilty or not.
> 
> I found that since base dbc920bd9a9b (linuxkpi interval_tree)
> linuxkpi.ko now exports some rb_* functions (from rbtree.h).  These are
> declared static inline but the compiler may decide not to inline them.
> These functions conflict with the ones in linuxkpi_gplv2.ko from
> drm-kmod, because both implementations use a different order for the
> fields in struct rb_node.

Here's a list of functions that linuxkpi.ko and linuxkpi_gplv2.ko have
in common in my case.  Some are probably ok.

device_register
i2c_transfer
linux_compat_init
lkpi_arch_phys_wc_add
lkpi_arch_phys_wc_del
rb_erase_cached
rb_insert_color_cached
sysctl_handle_attr