cbfb1b7443
While we don't need this function to store an mstb anywhere for UP
requests since we process them asynchronously, we do need to make sure
that we don't try to write to **mstb for UP requests otherwise we'll
cause a NULL pointer deref:
RIP: 0010:drm_dp_get_one_sb_msg+0x4b/0x460 [drm_kms_helper]
Call Trace:
? vprintk_emit+0x16a/0x230
? drm_dp_mst_hpd_irq+0x133/0x1010 [drm_kms_helper]
drm_dp_mst_hpd_irq+0x133/0x1010 [drm_kms_helper]
? __drm_dbg+0x87/0x90 [drm]
? intel_dp_hpd_pulse+0x24b/0x400 [i915]
intel_dp_hpd_pulse+0x24b/0x400 [i915]
i915_digport_work_func+0xd6/0x160 [i915]
process_one_work+0x1a9/0x370
worker_thread+0x4d/0x3a0
kthread+0xf9/0x130
? process_one_work+0x370/0x370
? kthread_park+0x90/0x90
ret_from_fork+0x35/0x40
So, fix this.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: fbc821c4a5 ("drm/mst: Support simultaneous down replies")
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Lyude Paul <lyude@redhat.com>
Cc: Wayne Lin <waynelin@amd.com>
Cc: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200406193352.1245985-1-lyude@redhat.com
Reviewed-by: Sean Paul <sean@poorly.run>
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.