[PATCH 6/8] drm/vram-helper: don't use ttm bo->offset v4
Thomas Zimmermann
tzimmermann at suse.de
Thu Sep 17 12:29:20 UTC 2020
Hi Christian
Am 17.09.20 um 13:12 schrieb Christian König:
> Hi Thomas,
>
> Am 17.09.20 um 12:51 schrieb Thomas Zimmermann:
>> Hi
>>
>> Am 24.06.20 um 20:26 schrieb Nirmoy Das:
>>> Calculate GEM VRAM bo's offset within vram-helper without depending on
>>> bo->offset.
>>>
>>> Signed-off-by: Nirmoy Das <nirmoy.das at amd.com>
>>> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>>> ---
>>> drivers/gpu/drm/drm_gem_vram_helper.c | 11 ++++++++++-
>>> 1 file changed, 10 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c
>>> b/drivers/gpu/drm/drm_gem_vram_helper.c
>>> index 0023ce1d2cf7..ad096600d89f 100644
>>> --- a/drivers/gpu/drm/drm_gem_vram_helper.c
>>> +++ b/drivers/gpu/drm/drm_gem_vram_helper.c
>>> @@ -281,6 +281,15 @@ u64 drm_gem_vram_mmap_offset(struct
>>> drm_gem_vram_object *gbo)
>>> }
>>> EXPORT_SYMBOL(drm_gem_vram_mmap_offset);
>>> +static u64 drm_gem_vram_pg_offset(struct drm_gem_vram_object *gbo)
>>> +{
>>> + /* Keep TTM behavior for now, remove when drivers are audited */
>>> + if (WARN_ON_ONCE(!gbo->bo.mem.mm_node))
>> At this line I got
>
> Sounds like ast forgot to pin the cursor to VRAM.
>
> If you look at ast_cursor_page_flip(), you see:
>> off = drm_gem_vram_offset(gbo);
>> if (drm_WARN_ON_ONCE(dev, off < 0))
>> return; /* Bug: we didn't pin the cursor HW BO to
>> VRAM. */
>
> The drm_WARN_ON_ONCE() just never triggered before because it checks for
> the wrong condition (off < 0).
GEM VRAM BOs have a pin counter. drm_gem_vram_offset() returns -ENODEV
if the BO's pin count is 0 (i.e., the BO has not been pinned anywhere).
That's what we're testing here. Two cursor BOs are permanently pinned to
the top of VRAM memory by ast_cursor_init(). If perma-pinning in
ast_cursor_init() fails, driver initialization should fail entirely.
These cursor BOs do some sort of double buffering, On successful
initialization, the actual cursor image is later blit-ed into one of the
BOs.
All this used to work from what I can tell. Is there any chance that the
recent TTM refactoring broke this?
Best regards
Thomas
>
> Regards,
> Christian.
>
>>
>> [ 146.133821] ------------[ cut here ]------------
>> [ 146.133872] WARNING: CPU: 6 PID: 7 at
>> drivers/gpu/drm/drm_gem_vram_helper.c:284 drm_gem_vram_offset+0x59/0x60
>> [drm_vram_helper]
>> [ 146.133880] Modules linked in: fuse(E) af_packet(E) ebtable_filter(E)
>> ebtables(E) ip6table_filter(E) ip6_tables(E) iptable_filter(E)
>> ip_tables(E) x_tables(E) bpfilter(E) rfkill(E) dmi_sysfs(E) msr(E)
>> intel_powerclamp(E) coretemp(E) kv)
>> [ 146.134051] scsi_dh_emc(E) scsi_dh_alua(E)
>> [ 146.134074] CPU: 6 PID: 7 Comm: kworker/u48:0 Tainted: G E
>> 5.9.0-rc4-1-default+ #492
>> [ 146.134083] Hardware name: Sun Microsystems SUN FIRE X2270 M2/SUN
>> FIRE X2270 M2, BIOS 2.05 07/01/2010
>> [ 146.134099] Workqueue: events_unbound commit_work
>> [ 146.134116] RIP: 0010:drm_gem_vram_offset+0x59/0x60 [drm_vram_helper]
>> [ 146.134128] Code: 02 00 00 00 74 24 48 8d bb 80 02 00 00 e8 ef 27 17
>> d7 48 8b 83 80 02 00 00 5b 48 c1 e0 0c c3 0f 0b 48 c7 c0 ed ff ff ff 5b
>> c3 <0f> 0b 31 c0 5b c3 90 66 66 66 66 90 41 56 41 55 49 89 d5 41 54 49
>> [ 146.134137] RSP: 0018:ffffc90000107c38 EFLAGS: 00010246
>> [ 146.134149] RAX: 0000000000000000 RBX: ffff888111155000 RCX:
>> ffffffffc032323b
>> [ 146.134158] RDX: dffffc0000000000 RSI: ffff88810e236300 RDI:
>> ffff888111155278
>> [ 146.134168] RBP: ffff888109090000 R08: ffffffffc0323225 R09:
>> 0000000000000002
>> [ 146.134177] R10: ffffed1020675020 R11: 0000000000000001 R12:
>> ffff888109091050
>> [ 146.134187] R13: ffff88810e236300 R14: ffff888109090000 R15:
>> 0000000000000000
>> [ 146.134197] FS: 0000000000000000(0000) GS:ffff888116000000(0000)
>> knlGS:0000000000000000
>> [ 146.134206] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [ 146.134215] CR2: 00007f60547d9100 CR3: 0000000029216002 CR4:
>> 00000000000206e0
>> [ 146.134223] Call Trace:
>> [ 146.134245] ast_cursor_page_flip+0x3e/0x150 [ast]
>> [ 146.134272] ast_cursor_plane_helper_atomic_update+0x8a/0xc0 [ast]
>> [ 146.134300] drm_atomic_helper_commit_planes+0x197/0x4c0
>> [ 146.134341] drm_atomic_helper_commit_tail_rpm+0x51/0x90
>> [ 146.134357] commit_tail+0x103/0x1c0
>> [ 146.134390] process_one_work+0x56a/0xa60
>> [ 146.134431] ? __lock_acquired+0x1ca/0x3d0
>> [ 146.134447] ? pwq_dec_nr_in_flight+0x110/0x110
>> [ 146.134460] ? __lock_contended+0x4a0/0x4a0
>> [ 146.134491] ? worker_thread+0x150/0x620
>> [ 146.134521] worker_thread+0x8b/0x620
>> [ 146.134539] ? _raw_spin_unlock_irqrestore+0x41/0x50
>> [ 146.134583] ? process_one_work+0xa60/0xa60
>> [ 146.134597] kthread+0x1e4/0x210
>> [ 146.134612] ? kthread_create_worker_on_cpu+0xb0/0xb0
>> [ 146.134637] ret_from_fork+0x22/0x30
>> [ 146.134698] irq event stamp: 74111
>> [ 146.134711] hardirqs last enabled at (74117): [<ffffffff971c68f9>]
>> console_unlock+0x539/0x670
>> [ 146.134723] hardirqs last disabled at (74122): [<ffffffff971c68ef>]
>> console_unlock+0x52f/0x670
>> [ 146.134737] softirqs last enabled at (73354): [<ffffffff975469d5>]
>> wb_workfn+0x3f5/0x430
>> [ 146.134749] softirqs last disabled at (73350): [<ffffffff973f81d0>]
>> wb_wakeup_delayed+0x40/0xa0
>> [ 146.134758] ---[ end trace 74dd5fac6a3a2c0c ]---
>>
>>
>> Happens with ast when doing
>>
>> weston-launch
>>
>>
>>
>>> + return 0;
>>> +
>>> + return gbo->bo.mem.start;
>>> +}
>>> +
>>> /**
>>> * drm_gem_vram_offset() - \
>>> Returns a GEM VRAM object's offset in video memory
>>> @@ -297,7 +306,7 @@ s64 drm_gem_vram_offset(struct
>>> drm_gem_vram_object *gbo)
>>> {
>>> if (WARN_ON_ONCE(!gbo->pin_count))
>>> return (s64)-ENODEV;
>>> - return gbo->bo.offset;
>>> + return drm_gem_vram_pg_offset(gbo) << PAGE_SHIFT;
>>> }
>>> EXPORT_SYMBOL(drm_gem_vram_offset);
>>>
>
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> dri-devel at lists.freedesktop.org
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--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer
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