447a011bb4
[ Upstream commit a9748134ea4aad989e52a6a91479e0acfd306e5b ] When putting iMX5 into suspend, the following flow is observed: [ 70.023427] [<c07755f0>] (msm_atomic_commit_tail) from [<c06e7218>] (commit_tail+0x9c/0x18c) [ 70.031890] [<c06e7218>] (commit_tail) from [<c0e2920c>] (drm_atomic_helper_commit+0x1a0/0x1d4) [ 70.040627] [<c0e2920c>] (drm_atomic_helper_commit) from [<c06e74d4>] (drm_atomic_helper_disable_all+0x1c4/0x1d4) [ 70.050913] [<c06e74d4>] (drm_atomic_helper_disable_all) from [<c0e2943c>] (drm_atomic_helper_suspend+0xb8/0x170) [ 70.061198] [<c0e2943c>] (drm_atomic_helper_suspend) from [<c06e84bc>] (drm_mode_config_helper_suspend+0x24/0x58) In the i.MX5 case, priv->kms is not populated (as i.MX5 does not use any of the Qualcomm display controllers), causing a NULL pointer dereference in msm_atomic_commit_tail(): [ 24.268964] 8<--- cut here --- [ 24.274602] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 24.283434] pgd = (ptrval) [ 24.286387] [00000000] *pgd=ca212831 [ 24.290788] Internal error: Oops: 17 [#1] SMP ARM [ 24.295609] Modules linked in: [ 24.298777] CPU: 0 PID: 197 Comm: init Not tainted 5.11.0-rc2-next-20210111 #333 [ 24.306276] Hardware name: Freescale i.MX53 (Device Tree Support) [ 24.312442] PC is at msm_atomic_commit_tail+0x54/0xb9c [ 24.317743] LR is at commit_tail+0xa4/0x1b0 Fix the problem by calling drm_mode_config_helper_suspend/resume() only when priv->kms is available. Fixes: ca8199f13498 ("drm/msm/dpu: ensure device suspend happens during PM sleep") Signed-off-by: Fabio Estevam <festevam@gmail.com> Signed-off-by: Rob Clark <robdclark@chromium.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.