[PATCH 05/11] drm/rockchip: Test for imported buffers with drm_gem_is_imported()

Tue Apr 15 07:15:14 UTC 2025

Hi Thomas，

在 2025-04-15 14:54:21，"Thomas Zimmermann" <tzimmermann at suse.de> 写道：
>Hi
>
>Am 15.04.25 um 06:00 schrieb Andy Yan:
>>
>> Hi Thomas，
>>
>> At 2025-04-14 21:48:12, "Thomas Zimmermann" <tzimmermann at suse.de> wrote:
>>> Instead of testing import_attach for imported GEM buffers, invoke
>>> drm_gem_is_imported() to do the test. The helper tests the dma_buf
>>> itself while import_attach is just an artifact of the import. Prepares
>>> to make import_attach optional.
>>>
>>> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>
>>> Cc: Sandy Huang <hjc at rock-chips.com>
>>> Cc: "Heiko Stübner" <heiko at sntech.de>
>>> Cc: Andy Yan <andy.yan at rock-chips.com>
>>> ---
>>> drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
>>> index 6330b883efc3..e44396d46dc1 100644
>>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
>>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
>>> @@ -332,7 +332,7 @@ void rockchip_gem_free_object(struct drm_gem_object *obj)
>>> 	struct rockchip_drm_private *private = drm->dev_private;
>>> 	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
>>>
>>> -	if (obj->import_attach) {
>>> +	if (drm_gem_is_imported(obj)) {
>>
>> After applying this patch, when I tested glmark2-es2-wayland under Weston, the weston would freeze.
>> It seems it goto the else path.
>>
>>   I'm still conducting further analysis to figure out the exact cause.
>
>Thanks for testing. We test if obj->dma_buf is set and refers back to 
>obj. One of these fields has likely been cleared already to NULL during 
>the object cleanup. Other drivers also call drm_gem_is_imported() in 
>their object cleanup and I've not heard about any regressions.

From my test, it seems that a dumb buffer may export then import:
and the obj->dma_buf will be cleared at drm_mode_destroy_dumb_ioctl-->drm_gem_handle_delete

then test with   obj->dma_buf && (obj->dma_buf->priv != obj) will be false.

[   12.028941] [drm] Initialized panthor 1.3.0 for fb000000.gpu on minor 1
[   14.606114] rockchip_gem_dumb_create weston obj: ffff00010149b000 handle: 1
[   14.606170] drm_gem_prime_handle_to_dmabuf weston obj: ffff00010149b000 dma_buf: 0xffff000101454800 handle: 1
[   14.606217] drm_gem_prime_fd_to_handle weston obj: ffff0001023cdc00 dma_buf: 0xffff000101454800 dma_buf->priv ffff00010149b000
[   14.685517] rockchip_gem_dumb_create weston obj: ffff00010149b400 handle: 2
[   14.685569] drm_gem_prime_handle_to_dmabuf weston obj: ffff00010149b400 dma_buf: 0xffff000101454400 handle: 2
[   14.685691] drm_gem_prime_fd_to_handle weston obj: ffff0001023ce600 dma_buf: 0xffff000101454400 dma_buf->priv ffff00010149b400
[   15.255277] rockchip_gem_dumb_create weston obj: ffff00010759f800 handle: 3
[   15.255298] drm_gem_prime_handle_to_dmabuf weston obj: ffff00010759f800 dma_buf: 0xffff0001030cbc00 handle: 3
[   15.255317] drm_gem_prime_fd_to_handle weston obj: ffff0001037a3200 dma_buf: 0xffff0001030cbc00 dma_buf->priv ffff00010759f800
[   15.316336] rockchip_gem_dumb_create weston obj: ffff00010759f000 handle: 4
[   15.316360] drm_gem_prime_handle_to_dmabuf weston obj: ffff00010759f000 dma_buf: 0xffff0001030cba00 handle: 4
[   15.316404] drm_gem_prime_fd_to_handle weston obj: ffff0001037a1000 dma_buf: 0xffff0001030cba00 dma_buf->priv ffff00010759f000
[   20.209006] rockchip_gem_dumb_create weston obj: ffff000106584000 handle: 1
[   20.209031] drm_gem_prime_handle_to_dmabuf weston obj: ffff000106584000 dma_buf: 0xffff0001017a7600 handle: 1
[   20.209049] drm_gem_prime_fd_to_handle weston obj: ffff00010182fc00 dma_buf: 0xffff0001017a7600 dma_buf->priv ffff000106584000
[   20.228008] rockchip_gem_dumb_create weston obj: ffff000106584c00 handle: 2
[   20.228029] drm_gem_prime_handle_to_dmabuf weston obj: ffff000106584c00 dma_buf: 0xffff0001017a7a00 handle: 2
[   20.228081] drm_gem_prime_fd_to_handle weston obj: ffff000105eec000 dma_buf: 0xffff0001017a7a00 dma_buf->priv ffff000106584c00

[   27.073265] drm_gem_prime_handle_to_dmabuf glmark2-es2-way obj: ffff0001035f0a00 dma_buf: 0xffff00010a24d500 handle: 10
[   27.073377] drm_gem_prime_fd_to_handle weston obj: ffff0001035f0a00 dma_buf: 0xffff00010a24d500 dma_buf->priv ffff0001035f0a00
[   27.073718] drm_gem_prime_fd_to_handle weston obj: ffff00010759e000 dma_buf: 0xffff00010a24d500 dma_buf->priv ffff0001035f0a00

[   27.075363] drm_gem_handle_delete glmark2-es2-way obj: ffff0001035f0a00 handle: 10
[   27.075718] drm_gem_prime_handle_to_dmabuf glmark2-es2-way obj: ffff00012946e000 dma_buf: 0xffff00010a24d100 handle: 25
[   27.075799] drm_gem_prime_fd_to_handle weston obj: ffff00012946e000 dma_buf: 0xffff00010a24d100 dma_buf->priv ffff00012946e000
[   27.076613] drm_gem_prime_fd_to_handle weston obj: ffff00010759dc00 dma_buf: 0xffff00010a24d100 dma_buf->priv ffff00012946e000
[   27.079195] drm_gem_prime_handle_to_dmabuf glmark2-es2-way obj: ffff00012946e400 dma_buf: 0xffff00010a24d000 handle: 10
[   27.079262] drm_gem_handle_delete weston obj: ffff00010759e000 handle: 5
[   27.079271] CPU: 7 UID: 0 PID: 308 Comm: weston Not tainted 6.15.0-rc1+ #613 PREEMPT 
[   27.079276] Hardware name: Radxa ROCK 5B (DT)
[   27.079278] Call trace:
[   27.079280]  show_stack+0x18/0x24 (C)
[   27.079289]  dump_stack_lvl+0x74/0x8c
[   27.079296]  dump_stack+0x18/0x24
[   27.079301]  drm_gem_object_handle_put_unlocked+0x58/0x128
[   27.079309]  drm_gem_handle_delete+0xbc/0x110
[   27.079314]  drm_mode_destroy_dumb_ioctl+0x24/0x3c
[   27.079318]  drm_ioctl_kernel+0xc0/0x12c
[   27.079324]  drm_ioctl+0x25c/0x55c
[   27.079330]  __arm64_sys_ioctl+0xb4/0xe8
[   27.079335]  invoke_syscall+0x48/0x10c
[   27.079340]  el0_svc_common.constprop.0+0x40/0xe0
[   27.079346]  do_el0_svc+0x1c/0x28
[   27.079351]  el0_svc+0x30/0xcc
[   27.079355]  el0t_64_sync_handler+0x10c/0x138
[   27.079358]  el0t_64_sync+0x198/0x19c
[   27.079362] drm_gem_object_exported_dma_buf_free weston obj: ffff00010759e000 dma_buf: 0xffff00010a24d500 dma_buf->priv: ffff0001035f0a00
[   27.085797] rockchip_gem_free_object weston obj: ffff00010759e000 import dma_buf: 0x0000000000000000 dma_buf->priv: 0000000000000000
[   27.086093] drm_gem_handle_delete weston obj: ffff0001035f0a00 handle: 35
[   27.086099] CPU: 7 UID: 0 PID: 308 Comm: weston Not tainted 6.15.0-rc1+ #613 PREEMPT 
[   27.086102] Hardware name: Radxa ROCK 5B (DT)
>
>Best regards
>Thomas
>
>>
>>> 		if (private->domain) {
>>> 			rockchip_gem_iommu_unmap(rk_obj);
>>> 		} else {
>>> -- 
>>> 2.49.0
>
>-- 
>--
>Thomas Zimmermann
>Graphics Driver Developer
>SUSE Software Solutions Germany GmbH
>Frankenstrasse 146, 90461 Nuernberg, Germany
>GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
>HRB 36809 (AG Nuernberg)