22055eddd4
i915->hotplug.dig_port_work can be queued from intel_hpd_irq_handler called by IRQ handler or by intel_hpd_trigger_irq called from dp_mst. Since dp_mst is suspended after irq handler uninstall, a cleaner approach is to cancel hpd work after intel_dp_mst_suspend, otherwise we risk use-after-free. It should fix following WARNINGS: [283.405824] cpu_latency_qos_update_request called for unknown object [283.405866] WARNING: CPU: 2 PID: 240 at kernel/power/qos.c:296 cpu_latency_qos_update_request+0x2d/0x100 [283.405912] CPU: 2 PID: 240 Comm: kworker/u64:9 Not tainted 5.18.0-rc6-Patchwork_103738v3-g1672d1c43e43+ #1 [283.405915] Hardware name: Intel Corporation Raptor Lake Client Platform/RPL-S ADP-S DDR5 UDIMM CRB, BIOS RPLSFWI1.R00.2397.A01.2109300731 09/30/2021 [283.405916] Workqueue: i915-dp i915_digport_work_func [i915] [283.406020] RIP: 0010:cpu_latency_qos_update_request+0x2d/0x100 ... [283.406040] Call Trace: [283.406041] <TASK> [283.406044] intel_dp_aux_xfer+0x60e/0x8e0 [i915] [283.406131] ? finish_swait+0x80/0x80 [283.406139] intel_dp_aux_transfer+0xc5/0x2b0 [i915] [283.406218] drm_dp_dpcd_access+0x79/0x130 [drm_display_helper] [283.406227] drm_dp_dpcd_read+0xe2/0xf0 [drm_display_helper] [283.406233] intel_dp_hpd_pulse+0x134/0x570 [i915] [283.406308] ? __down_killable+0x70/0x140 [283.406313] i915_digport_work_func+0xba/0x150 [i915] Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/4586 Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/5558 Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com> Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com> Reviewed-by: Imre Deak <imre.deak@intel.com> Signed-off-by: Imre Deak <imre.deak@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220826141929.189681-2-andrzej.hajda@intel.com
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.