Comment 4 for bug 1768898

------- Comment From <email address hidden> 2018-05-13 00:08 EDT-------
(In reply to comment #32)
> I built a test kernel with commit c0f7f5b6c69107ca92909512533e70258ee19188.
> The test kernel can be downloaded from:
> http://kernel.ubuntu.com/~jsalisbury/lp1768898
>
> Can you test this kernel and see if it resolves this bug?
>
> Note about installing test kernels:
> ? If the test kernel is prior to 4.15(Bionic) you need to install the
> linux-image and linux-image-extra .deb packages.
> ? If the test kernel is 4.15(Bionic) or newer, you need to install the
> linux-image-unsigned, linux-modules and linux-modules-extra .deb packages.
>
> Thanks in advance!

System is having bionic kernel, while installing the above packages getting an error.
root@ltc-boston125:~/test_bug# ls
linux-image-unsigned-4.15.0-20-generic_4.15.0-20.21~lp1768898_ppc64el.deb linux-modules-extra-4.15.0-20-generic_4.15.0-20.21~lp1768898_ppc64el.deb
linux-modules-4.15.0-20-generic_4.15.0-20.21~lp1768898_ppc64el.deb
root@ltc-boston125:~/test_bug# dpkg -i *.deb
Selecting previously unselected package linux-image-unsigned-4.15.0-20-generic.
dpkg: regarding linux-image-unsigned-4.15.0-20-generic_4.15.0-20.21~lp1768898_ppc64el.deb containing linux-image-unsigned-4.15.0-20-generic:
linux-image-unsigned-4.15.0-20-generic conflicts with linux-image-4.15.0-20-generic
linux-image-4.15.0-20-generic (version 4.15.0-20.21) is present and installed.

dpkg: error processing archive linux-image-unsigned-4.15.0-20-generic_4.15.0-20.21~lp1768898_ppc64el.deb (--install):
conflicting packages - not installing linux-image-unsigned-4.15.0-20-generic
dpkg: warning: downgrading linux-modules-4.15.0-20-generic from 4.15.0-20.21 to 4.15.0-20.21~lp1768898
(Reading database ... 67065 files and directories currently installed.)
Preparing to unpack linux-modules-4.15.0-20-generic_4.15.0-20.21~lp1768898_ppc64el.deb ...
Unpacking linux-modules-4.15.0-20-generic (4.15.0-20.21~lp1768898) over (4.15.0-20.21) ...
dpkg: warning: downgrading linux-modules-extra-4.15.0-20-generic from 4.15.0-20.21 to 4.15.0-20.21~lp1768898
Preparing to unpack linux-modules-extra-4.15.0-20-generic_4.15.0-20.21~lp1768898_ppc64el.deb ...
Unpacking linux-modules-extra-4.15.0-20-generic (4.15.0-20.21~lp1768898) over (4.15.0-20.21) ...
Setting up linux-modules-4.15.0-20-generic (4.15.0-20.21~lp1768898) ...
Setting up linux-modules-extra-4.15.0-20-generic (4.15.0-20.21~lp1768898) ...
Processing triggers for linux-image-4.15.0-20-generic (4.15.0-20.21) ...
/etc/kernel/postinst.d/initramfs-tools:
update-initramfs: Generating /boot/initrd.img-4.15.0-20-generic
W: Possible missing firmware /lib/firmware/ast_dp501_fw.bin for module ast
/etc/kernel/postinst.d/zz-update-grub:
Generating grub configuration file ...
Found linux image: /boot/vmlinux-4.15.0-20-generic
Found initrd image: /boot/initrd.img-4.15.0-20-generic
done
Errors were encountered while processing:
linux-image-unsigned-4.15.0-20-generic_4.15.0-20.21~lp1768898_ppc64el.deb

uname -a
Linux ltc-boston125 4.15.0-20-generic #21-Ubuntu SMP Tue Apr 24 06:14:44 UTC 2018 ppc64le ppc64le ppc64le GNU/Linux

Can you please let me know why it is failing to install.