On Tue, Apr 24, 2018 at 08:48:42PM +0000, Deucher, Alexander wrote:
-----Original Message----- From: Ben Crocker [mailto:bcrocker@redhat.com] Sent: Tuesday, April 24, 2018 3:30 PM To: gregkh@linuxfoundation.org Cc: Deucher, Alexander Alexander.Deucher@amd.com; stable@vger.kernel.org Subject: Re: FAILED: patch "[PATCH] drm/radeon: insist on 32-bit DMA for Cedar on PPC64/PPC64LE" failed to apply to 4.16-stable tree
(Third try, after turning on Plain Text mode in Gmail; apologies if you got this more than once)
Hi Greg,
Thanks for the note. I think this is a case of the same change having been checked in on different branches. I downloaded the linux-4.16.3 tarball, unpacked it, and examined radeon_device.c; the correct change is there in radeon_device_init (the four lines beginning "#ifdef CONFIG_PPC64").
Looking at the whole git log, I see two instances of exactly the same patch:
commit bcb0b981c5571744ac446a6c906aa05a28d21446 Author: Ben Crocker bcrocker@redhat.com Date: Thu Feb 22 17:52:19 2018 -0500
drm/radeon: insist on 32-bit DMA for Cedar on PPC64/PPC64LEand
commit 2c83029cda55a5e7665c7c6326909427d6a01350 Author: Ben Crocker bcrocker@redhat.com Date: Thu Feb 22 17:52:19 2018 -0500
drm/radeon: insist on 32-bit DMA for Cedar on PPC64/PPC64LEA colleague of mine here at Red Hat thinks that no further action is necessary; please let me know what you think.
No further action is required. The patch was committed to drm-next for the next kernel and also ended up in drm-fixes for the current one at the time.
And it's annoying as hell.
I already argued a lot with the i915 maintainers about this in the past, but for them, at least they have the crazy "cherry-picked from..." tag in there showing how they are cherry picking from a _FUTURE_ commit, which gives me a hint as to the lunacy that is happening so I can properly detect it when it hits the tree for the second time.
But for these patches I have no clue.
Which is why all stable DRM driver patches are at the absolute bottom of my priority queue and I dread seeing them ever show up as I don't know what mess is going to happen whenever I try to apply them.
If you are going to do this more often in the future, at least give me a fighting chance to detect it is happening. Otherwise you will get a lot of these "FAILED" emails happening, along with me just starting to ignore radeon stable patches, like I do for i915, until they pile up and I have nothing else better to do that day.
What a mess...
greg k-h