On 5/23/2023 8:24 AM, Johan Hovold wrote:
On Fri, May 12, 2023 at 09:13:04PM +0300, Dmitry Baryshkov wrote:
On 28/04/2023 02:28, Abhinav Kumar wrote:
On sc7280 where eDP is the primary display, PSR is causing
IGT breakage even for basic test cases like kms_atomic and
kms_atomic_transition. Most often the issue starts with below
stack so providing that as reference
Call trace:
dpu_encoder_assign_crtc+0x64/0x6c
dpu_crtc_enable+0x188/0x204
drm_atomic_helper_commit_modeset_enables+0xc0/0x274
msm_atomic_commit_tail+0x1a8/0x68c
commit_tail+0xb0/0x160
drm_atomic_helper_commit+0x11c/0x124
drm_atomic_commit+0xb0/0xdc
drm_atomic_connector_commit_dpms+0xf4/0x110
drm_mode_obj_set_property_ioctl+0x16c/0x3b0
drm_connector_property_set_ioctl+0x4c/0x74
drm_ioctl_kernel+0xec/0x15c
drm_ioctl+0x264/0x408
__arm64_sys_ioctl+0x9c/0xd4
invoke_syscall+0x4c/0x110
el0_svc_common+0x94/0xfc
do_el0_svc+0x3c/0xb0
el0_svc+0x2c/0x7c
el0t_64_sync_handler+0x48/0x114
el0t_64_sync+0x190/0x194
---[ end trace 0000000000000000 ]---
[drm-dp] dp_ctrl_push_idle: PUSH_IDLE pattern timedout
Other basic use-cases still seem to work fine hence add a
a module parameter to allow toggling psr enable/disable till
PSR related issues are hashed out with IGT.
For the reference: Bjorn reported that he has issues with VT on a
PSR-enabled laptops. This patch fixes the issue for him
Module parameters are almost never warranted, and it is definitely not
the right way to handle a broken implementation.
I've just sent a revert that unconditionally disables PSR support until
the implementation has been fixed:
https://lore.kernel.org/lkml/20230523151646.28366-1-johan+linaro@xxxxxxxxxx/
Johan
I dont completely agree with this. Even the virtual terminal case was
reported to be fixed by one user but not the other. So it was probably
something missed out either in validation or reproduction steps of the
user who reported it to be fixed OR the user who reported it not fixed.
That needs to be investigated now.
We should have ideally gone with the modparam with the feature patches
itself knowing that it gets enabled for all sinks if PSR is supported.
I had discussed with Rob that till we have some more confidence with the
reported issues we would go with the modparam so as to not do the full
revert.
In this particular case, the one line revert is not really a deal
breaker. In some other implementations, it might not really be so
trivial to revert the feature with a one line change.
So I would like to understand what is the concern with the mod param if
the maintainers are onboard with it.
