APPLIED/cmt: psp response issue on ubuntu 19.04 disco kernel

[Seth Forshee]

On Fri, Mar 29, 2019 at 11:57:39AM +0000, Yang, Adam wrote:
> Hi Canonical kernel team,
> 
> I'm an engineer for AMD and we've discovered an issue that causes the kernel hang during boot in Ubuntu 19.04. After querying with the canonical team, they introduce that it is better to send the patch directly here.
> 
> 
> ----- background information -----
> 
> I’m Adam from AMD to help improve Ubuntu user experiences and ecosystem on AMD platforms.
> 
> Currently I have worked on a bug on AMD Raven 2 platform and hope that the critical issue is merged in the kernel before the kernel freezes on April 4 th.
> I have updated the issue information on Launchpad at https://bugs.launchpad.net/amd/+bug/1822267.
> 
> In case that the page permission is not correctly setup, I’d attach the issue in the plain text form as following and the backport patch as a file:
> 
> -----
> Title: [Patch][Raven 2] kernel 5.0.0 cannot boot because of psp response
> 
> Bug Description:
> 
> Description:
> 
> Raven 2 platform fails to boot on ubuntu 19.04 (disco) with kernel 5.0.0. The issue is related to a fixed patch in linux-mainline about psp response code status.
> 
> In some cases, psp response status is not 0 even there is no problem while the command is submitted. Some version of PSP FW doesn't write 0 to that field. So here we would like to only print a warning instead of an error during psp initialization to avoid breaking hw_init and it doesn't return -EINVAL.
> 
> Steps:
> 1. Install Ubuntu 19.04 daily build on AMD Raven 2 platform (reproduced with 2019.03.18 version)
> 2. Reboot and it fails at kernel initialization.
> 
> Current patch status:
> A patch has already accepted in the linux mainline. (id: 466bcb75b0791ba301817cdadeed20398f2224fe)
> See: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=466bcb75b0791ba301817cdadeed20398f2224fe
> 
> Backport status:
> A backport patch is available and verified.

Thanks for the patch. It appears though that the patch is actually two
upstream patches squashed together:
76223c5496a7cf10aef1971e4e6aff77abadd15a and
466bcb75b0791ba301817cdadeed20398f2224fe. It's preferable to apply both
patches individually. I went ahead and applied both cherry-picks to our
disco kernel tree.

For future reference, we require that the upstream commit ids be
included using (more or less) the format produced by 'git cherry-pick
-x', which means either "(cherry picked from commit ..)" if the patch
applies cleanly or "(backported from commit ...)" if backports were
required. We have tools which understands this format for checking
whether or not specific upstream fixes have been applied to our trees.

Additionally, please include a line like this in the commit message to
reference the bug report:

BugLink: https://bugs.launchpad.net/bugs/1822267

replacing the bug number with the number of the bug report fixed by the
patch(es). Among other things this will ensure that the bug report is
closed when a kernel containing the fix is released.

Thanks,
Seth