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  1. 20 Oct, 2018 1 commit
  3. 19 Oct, 2018 2 commits
  5. 18 Oct, 2018 1 commit
    • Leo Li's avatar
      drm: Get ref on CRTC commit object when waiting for flip_done · 4364bcb2
      Leo Li authored 
      This fixes a general protection fault, caused by accessing the contents
of a flip_done completion object that has already been freed. It occurs
due to the preemption of a non-blocking commit worker thread W by
another commit thread X. X continues to clear its atomic state at the
end, destroying the CRTC commit object that W still needs. Switching
back to W and accessing the commit objects then leads to bad results.

Worker W becomes preemptable when waiting for flip_done to complete. At
this point, a frequently occurring commit thread X can take over. Here's
an example where W is a worker thread that flips on both CRTCs, and X
does a legacy cursor update on both CRTCs:

        ...
     1. W does flip work
     2. W runs commit_hw_done()
     3. W waits for flip_done on CRTC 1
     4. > flip_done for CRTC 1 completes
     5. W finishes waiting for CRTC 1
     6. W waits for flip_done on CRTC 2

     7. > Preempted by X
     8. > flip_done for CRTC 2 completes
     9. X atomic_check: hw_done and flip_done are complete on all CRTCs
    10. X updates cursor on both CRTCs
    11. X destroys atomic state
    12. X done

    13. > Switch back to W
    14. W waits for flip_done on CRTC 2
    15. W raises general protection fault

The error looks like so:

    general protection fault: 0000 [#1] PREEMPT SMP PTI
    **snip**
    Call Trace:
     lock_acquire+0xa2/0x1b0
     _raw_spin_lock_irq+0x39/0x70
     wait_for_completion_timeout+0x31/0x130
     drm_atomic_helper_wait_for_flip_done+0x64/0x90 [drm_kms_helper]
     amdgpu_dm_atomic_commit_tail+0xcae/0xdd0 [amdgpu]
     commit_tail+0x3d/0x70 [drm_kms_helper]
     process_one_work+0x212/0x650
     worker_thread+0x49/0x420
     kthread+0xfb/0x130
     ret_from_fork+0x3a/0x50
    Modules linked in: x86_pkg_temp_thermal amdgpu(O) chash(O)
    gpu_sched(O) drm_kms_helper(O) syscopyarea sysfillrect sysimgblt
    fb_sys_fops ttm(O) drm(O)

Note that i915 has this issue masked, since hw_done is signaled after
waiting for flip_done. Doing so will block the cursor update from
happening until hw_done is signaled, preventing the cursor commit from
destroying the state.

v2: The reference on the commit object needs to be obtained before
    hw_done() is signaled, since that's the point where another commit
    is allowed to modify the state. Assuming that the
    new_crtc_state->commit object still exists within flip_done() is
    incorrect.

    Fix by getting a reference in setup_commit(), and releasing it
    during default_clear().
Signed-off-by: default avatarLeo Li <sunpeng.li@amd.com>
Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: default avatarHarry Wentland <harry.wentland@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1539611200-6184-1-git-send-email-sunpeng.li@amd.com
      4364bcb2
  7. 16 Oct, 2018 1 commit
  9. 15 Oct, 2018 1 commit
  11. 14 Oct, 2018 2 commits
  13. 13 Oct, 2018 11 commits
  15. 12 Oct, 2018 18 commits
  17. 11 Oct, 2018 3 commits
    • David S. Miller's avatar
      Merge branch 'net-dsa-bcm_sf2-Couple-of-fixes' · 6b9bab55
      David S. Miller authored 
      Florian Fainelli says:

====================
net: dsa: bcm_sf2: Couple of fixes

Here are two fixes for the bcm_sf2 driver that were found during
testing unbind and analysing another issue during system
suspend/resume.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      6b9bab55
    • Florian Fainelli's avatar
      net: dsa: bcm_sf2: Call setup during switch resume · 54baca09
      Florian Fainelli authored 
      There is no reason to open code what the switch setup function does, in
fact, because we just issued a switch reset, we would make all the
register get their default values, including for instance, having unused
port be enabled again and wasting power and leading to an inappropriate
switch core clock being selected.

Fixes: 8cfa9498 ("net: dsa: bcm_sf2: add suspend/resume callbacks")
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      54baca09
    • Florian Fainelli's avatar
      net: dsa: bcm_sf2: Fix unbind ordering · bf3b452b
      Florian Fainelli authored 
      The order in which we release resources is unfortunately leading to bus
errors while dismantling the port. This is because we set
priv->wol_ports_mask to 0 to tell bcm_sf2_sw_suspend() that it is now
permissible to clock gate the switch. Later on, when dsa_slave_destroy()
comes in from dsa_unregister_switch() and calls
dsa_switch_ops::port_disable, we perform the same dismantling again, and
this time we hit registers that are clock gated.

Make sure that dsa_unregister_switch() is the first thing that happens,
which takes care of releasing all user visible resources, then proceed
with clock gating hardware. We still need to set priv->wol_ports_mask to
0 to make sure that an enabled port properly gets disabled in case it
was previously used as part of Wake-on-LAN.

Fixes: d9338023 ("net: dsa: bcm_sf2: Make it a real platform device driver")
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bf3b452b
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