On Fri, May 08, 2020 at 01:59:17PM +0200, Yves-Alexis Perez wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA256 > > On Fri, 2020-05-08 at 11:54 +0200, Greg KH wrote: > > > Hi Daniel and Greg (especially). It seems that this patch was never > > > applied to > > > stable, maybe it fell through the cracks? > > > > What patch is "this patch"? > > Sorry, the patch was in the mail I was replying to: > > commit 26b1d3b527e7bf3e24b814d617866ac5199ce68d > Author: Daniel Vetter <daniel.vetter@xxxxxxxx> > Date: Thu Sep 5 20:53:18 2019 +0200 > > drm/atomic: Take the atomic toys away from X > > > > > > It doesn't apply as-is in 4.19 branch but a small change in the context > > > makes > > > it apply. I'm experiencing issues with lightdm and vt-switch in Debian > > > Buster > > > (which has a 4.19 kernel) so I'd appreciate if the patch was included in > > > at > > > least that release. > > > > What is the git commit id of the patch in Linus's tree? If you have a > > working backport, that makes it much easier than hoping I can fix it > > up... > > The commit id is in Linus tree is 26b1d3b527e7bf3e24b814d617866ac5199ce68d. To > apply properly 69fdf4206a8ba91a277b3d50a3a05b71247635b2 would need to be > cherry-picked as well but it wasn't marked for stable so I didn't bother and > only fixed the context. Here's the backport to 4.19, compile and runtime > tested. It does fix the issue for me (like it did on mainline). > > So I guess > Tested-By: Yves-Alexis Perez <corsac@xxxxxxxxxx> > > commit 8a99914f7b539542622dc571c82d6cd203bddf64 > Author: Daniel Vetter <daniel.vetter@xxxxxxxx> > Date: Thu Sep 5 20:53:18 2019 +0200 > > drm/atomic: Take the atomic toys away from X > > The -modesetting ddx has a totally broken idea of how atomic works: > - doesn't disable old connectors, assuming they get auto-disable like > with the legacy setcrtc > - assumes ASYNC_FLIP is wired through for the atomic ioctl > - not a single call to TEST_ONLY > > Iow the implementation is a 1:1 translation of legacy ioctls to > atomic, which is a) broken b) pointless. > > We already have bugs in both i915 and amdgpu-DC where this prevents us > from enabling neat features. > > If anyone ever cares about atomic in X we can easily add a new atomic > level (req->value == 2) for X to get back the shiny toys. > > Since these broken versions of -modesetting have been shipping, > there's really no other way to get out of this bind. > > v2: > - add an informational dmesg output (Rob, Ajax) > - reorder after the DRIVER_ATOMIC check to avoid useless noise (Ilia) > - allow req->value > 2 so that X can do another attempt at atomic in > the future > > v3: Go with paranoid, insist that the X should be first (suggested by > Rob) > > Cc: Ilia Mirkin <imirkin@xxxxxxxxxxxx> > References: https://gitlab.freedesktop.org/xorg/xserver/issues/629 > References: https://gitlab.freedesktop.org/xorg/xserver/merge_requests/180 > References: abbc0697d5fb ("drm/fb: revert the i915 Actually configure > untiled displays from master") > Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> > Reviewed-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> (v1) > Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx> (v1) > Cc: Michel Dänzer <michel@xxxxxxxxxxx> > Cc: Alex Deucher <alexdeucher@xxxxxxxxx> > Cc: Adam Jackson <ajax@xxxxxxxxxx> > Acked-by: Adam Jackson <ajax@xxxxxxxxxx> > Cc: Sean Paul <sean@xxxxxxxxxx> > Cc: David Airlie <airlied@xxxxxxxx> > Cc: Rob Clark <robdclark@xxxxxxxxx> > Acked-by: Rob Clark <robdclark@xxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> > Link: > https://patchwork.freedesktop.org/patch/msgid/20190905185318.31363-1-daniel.vetter@xxxxxxxx > > diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c > index ba129b64b61f..b92682f037b2 100644 > - --- a/drivers/gpu/drm/drm_ioctl.c > +++ b/drivers/gpu/drm/drm_ioctl.c > @@ -321,7 +321,12 @@ drm_setclientcap(struct drm_device *dev, void *data, > struct drm_file *file_priv) > case DRM_CLIENT_CAP_ATOMIC: > if (!drm_core_check_feature(dev, DRIVER_ATOMIC)) > return -EINVAL; > - - if (req->value > 1) > + /* The modesetting DDX has a totally broken idea of atomic. */ > + if (current->comm[0] == 'X' && req->value == 1) { > + pr_info("broken atomic modeset userspace detected, > disabling atomic\n"); > + return -EOPNOTSUPP; > + } > + if (req->value > 2) > return -EINVAL; > file_priv->atomic = req->value; > file_priv->universal_planes = req->value; > This is line-wrapped and can not be applied :( Ugh, let me see if I can do this by hand... greg k-h
