[PATCH] drm/ttm: fix regression in ttm moves

[Christian König]

That sounds like the same problem I've got when drm-next was merged into 
drm-misc-next.

I've fixed it in this commit:

commit 0b06286579b81449b1e8f14f88d3a8db091fd443
Author: Christian König <christian.koenig at amd.com>
Date:   Wed Aug 19 15:27:48 2020 +0200

     drm/ttm: fix broken merge between drm-next and drm-misc-next

     drm-next reverted the changes to ttm_tt_create() to do the
     NULL check inside the function, but drm-misc-next adds new
     users of this approach.

     Re-apply the NULL check change inside the function to fix this.

     Signed-off-by: Christian König <christian.koenig at amd.com>
     Reviewed-by: Dave Airlie <airlied at redhat.com>
     Link: https://patchwork.freedesktop.org/patch/386628/


Not sure why it should cause problems with drm-fixes and drm-next as well.

Regards,
Christian.

Am 30.09.20 um 09:09 schrieb Dave Airlie:
> just FYI I'm seeing a regression on vmwgfx with drm-fixes and drm-next
> merged into it.
>
> I'm going take some time to dig through and work out where, the
> regression is a command failure and a ioremap failure.
>
> Dave.
>
> On Wed, 30 Sep 2020 at 16:26, Dave Airlie <airlied at gmail.com> wrote:
>> Uggh this is part of the mess with the revert, I'm not sure how best
>> to dig out of this one yet.
>>
>> Dave.
>>
>> On Wed, 30 Sep 2020 at 15:55, Dave Airlie <airlied at gmail.com> wrote:
>>> From: Dave Airlie <airlied at redhat.com>
>>>
>>> This fixes a bug introduced in be1213a341a289afc51f89181c310e368fba0b66
>>> drm/ttm: remove TTM_MEMTYPE_FLAG_FIXED v2
>>>
>>> On vmwgfx this causes a Command buffer error WARN to trigger.
>>>
>>> This is because the old code used to check if bo->ttm was true,
>>> and the new code doesn't, fix it code to add back the check resolves
>>> the issue.
>>>
>>> Fixes: be1213a341a2 ("drm/ttm: remove TTM_MEMTYPE_FLAG_FIXED v2")
>>> Signed-off-by: Dave Airlie <airlied at redhat.com>
>>> ---
>>>   drivers/gpu/drm/ttm/ttm_bo.c | 8 +++++---
>>>   1 file changed, 5 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
>>> index 70b3bee27850..e8aa2fe8e9d1 100644
>>> --- a/drivers/gpu/drm/ttm/ttm_bo.c
>>> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
>>> @@ -251,9 +251,11 @@ static int ttm_bo_handle_move_mem(struct ttm_buffer_object *bo,
>>>                  /* Zero init the new TTM structure if the old location should
>>>                   * have used one as well.
>>>                   */
>>> -               ret = ttm_tt_create(bo, old_man->use_tt);
>>> -               if (ret)
>>> -                       goto out_err;
>>> +               if (!bo->ttm) {
>>> +                       ret = ttm_tt_create(bo, old_man->use_tt);
>>> +                       if (ret)
>>> +                               goto out_err;
>>> +               }
>>>
>>>                  ret = ttm_tt_set_placement_caching(bo->ttm, mem->placement);
>>>                  if (ret)
>>> --
>>> 2.20.1
>>>
>>> _______________________________________________
>>> dri-devel mailing list
>>> dri-devel at lists.freedesktop.org
>>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&data=02%7C01%7Cchristian.koenig%40amd.com%7Ca8e51dce1b1346015c1e08d8650fdc59%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637370466085507013&sdata=QrtSgfkmSpNcNfdJ71YNATS0URyEcMNLeMVmOenRpak%3D&reserved=0