> Yeah, looks like a bug. I think the attached patch should fix it.
Sounds logical and the patch is Reviewed-by: Christian K?nig <christian.koenig
at amd.com>
Going to apply Maartens patch on top and test that one a bit to make sure it
works as expected.
Regards,
Christian.
Am 18.08.2014 um 18:03 schrieb Alex Deucher:
> On Mon, Aug 18, 2014 at 11:02 AM, Christian K?nig
> <deathsimple at vodafone.de> wrote:
>> Am 18.08.2014 um 16:45 schrieb Maarten Lankhorst:
>>
>>> This is needed for the next commit, because the lockup detection
>>> will need the read lock to run.
>>>
>>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com>
>>> ---
>>> drivers/gpu/drm/radeon/radeon.h | 2 +-
>>> drivers/gpu/drm/radeon/radeon_device.c | 61
>>> ++++++++++++++++++++--------------
>>> 2 files changed, 37 insertions(+), 26 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/radeon/radeon.h
>>> b/drivers/gpu/drm/radeon/radeon.h
>>> index 9e1732eb402c..1d806983ec7b 100644
>>> --- a/drivers/gpu/drm/radeon/radeon.h
>>> +++ b/drivers/gpu/drm/radeon/radeon.h
>>> @@ -2312,7 +2312,7 @@ struct radeon_device {
>>> bool need_dma32;
>>> bool accel_working;
>>> bool fastfb_working; /* IGP feature*/
>>> - bool needs_reset;
>>> + bool needs_reset, in_reset;
>>> struct radeon_surface_reg surface_regs[RADEON_GEM_MAX_SURFACES];
>>> const struct firmware *me_fw; /* all family ME firmware */
>>> const struct firmware *pfp_fw; /* r6/700 PFP firmware */
>>> diff --git a/drivers/gpu/drm/radeon/radeon_device.c
>>> b/drivers/gpu/drm/radeon/radeon_device.c
>>> index c8ea050c8fa4..82633fdd399d 100644
>>> --- a/drivers/gpu/drm/radeon/radeon_device.c
>>> +++ b/drivers/gpu/drm/radeon/radeon_device.c
>>> @@ -1671,29 +1671,34 @@ int radeon_gpu_reset(struct radeon_device *rdev)
>>> down_write(&rdev->exclusive_lock);
>>> if (!rdev->needs_reset) {
>>> + WARN_ON(rdev->in_reset);
>>> up_write(&rdev->exclusive_lock);
>>> return 0;
>>> }
>>> rdev->needs_reset = false;
>>> -
>>> - radeon_save_bios_scratch_regs(rdev);
>>> - /* block TTM */
>>> resched = ttm_bo_lock_delayed_workqueue(&rdev->mman.bdev);
>>> - radeon_pm_suspend(rdev);
>>> - radeon_suspend(rdev);
>>> - for (i = 0; i < RADEON_NUM_RINGS; ++i) {
>>> - ring_sizes[i] = radeon_ring_backup(rdev, &rdev->ring[i],
>>> - &ring_data[i]);
>>> - if (ring_sizes[i]) {
>>> - saved = true;
>>> - dev_info(rdev->dev, "Saved %d dwords of commands "
>>> - "on ring %d.\n", ring_sizes[i], i);
>>> + if (!rdev->in_reset) {
>>> + rdev->in_reset = true;
>>> +
>>> + radeon_save_bios_scratch_regs(rdev);
>>> + /* block TTM */
>>> + radeon_pm_suspend(rdev);
>>> + radeon_suspend(rdev);
>>
>> That won't work correctly because you might end up with calling pm_resume
>> more often than suspend and that can only lead to a crash. Saying this we
>> probably already have a bug in the reset code at this point anyway, but see
>> below.
>>
>>
>>> +
>>> + for (i = 0; i < RADEON_NUM_RINGS; ++i) {
>>> + ring_sizes[i] = radeon_ring_backup(rdev,
>>> &rdev->ring[i],
>>> + &ring_data[i]);
>>> + if (ring_sizes[i]) {
>>> + saved = true;
>>> + dev_info(rdev->dev, "Saved %d dwords of
>>> commands "
>>> + "on ring %d.\n", ring_sizes[i],
>>> i);
>>> + }
>>> }
>>> - }
>>> + } else
>>> + memset(ring_data, 0, sizeof(ring_data));
>>> -retry:
>>> r = radeon_asic_reset(rdev);
>>> if (!r) {
>>> dev_info(rdev->dev, "GPU reset succeeded, trying to
>>> resume\n");
>>> @@ -1702,40 +1707,46 @@ retry:
>>> radeon_restore_bios_scratch_regs(rdev);
>>
>> We should resume PM here as well.
>>
>>
>>> - if (!r) {
>>> + if (!r && saved) {
>>> for (i = 0; i < RADEON_NUM_RINGS; ++i) {
>>> radeon_ring_restore(rdev, &rdev->ring[i],
>>> ring_sizes[i], ring_data[i]);
>>> - ring_sizes[i] = 0;
>>> ring_data[i] = NULL;
>>> }
>>> + } else {
>>> + radeon_fence_driver_force_completion(rdev);
>>> +
>>> + for (i = 0; i < RADEON_NUM_RINGS; ++i) {
>>> + kfree(ring_data[i]);
>>> + }
>>> + }
>>> + downgrade_write(&rdev->exclusive_lock);
>>> + ttm_bo_unlock_delayed_workqueue(&rdev->mman.bdev, resched);
>>
>> I would unlock the delayed_workqueue first and then downgrade the readlock.
>>
>>
>>> + if (!r) {
>>> r = radeon_ib_ring_tests(rdev);
>>> if (r) {
>>> dev_err(rdev->dev, "ib ring test failed (%d).\n",
>>> r);
>>> if (saved) {
>>> - saved = false;
>>> + /* if reset fails, try without saving data
>>> */
>>> + rdev->needs_reset = true;
>>> radeon_suspend(rdev);
>>> - goto retry;
>>> + up_read(&rdev->exclusive_lock);
>>> + return -EAGAIN;
>>> }
>>> }
>>> - } else {
>>> - radeon_fence_driver_force_completion(rdev);
>>> - for (i = 0; i < RADEON_NUM_RINGS; ++i) {
>>> - kfree(ring_data[i]);
>>> - }
>>> }
>>>
>>
>>> radeon_pm_resume(rdev);
>>
>> Move this more up.
>>
>> Alex is more into this, but it's probably a bug in the current reset code
>> that this is after the IB tests, cause the IB tests needs everything powered
>> up and with PM handling suspended it is possible that individual blocks are
>> powered down.
> Yeah, looks like a bug. I think the attached patch should fix it.
>
> Alex
>
>> Thanks,
>> Christian.
>>
>>
>>> drm_helper_resume_force_mode(rdev->ddev);
>>> - ttm_bo_unlock_delayed_workqueue(&rdev->mman.bdev, resched);
>>> if (r) {
>>> /* bad news, how to tell it to userspace ? */
>>> dev_info(rdev->dev, "GPU reset failed\n");
>>> }
>>> - up_write(&rdev->exclusive_lock);
>>> + rdev->in_reset = false;
>>> + up_read(&rdev->exclusive_lock);
>>> return r;
>>> }
>>>
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/dri-devel
