drm/amd/display: set per pipe dppclk to 0 when dpp is off
authorDmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Tue, 22 Nov 2022 15:06:19 +0000 (10:06 -0500)
committerAlex Deucher <alexander.deucher@amd.com>
Tue, 29 Nov 2022 16:03:38 +0000 (11:03 -0500)
commit6609141c49df1b86fbad26a8643d4b4044f28b11
treee46f3b58ae3a980541ab6a6a4e343cd78720262a
parentead08b95fa50f40618c72b93a849c4ae30c9cd50
drm/amd/display: set per pipe dppclk to 0 when dpp is off

The 'commit 52e4fdf09ebc ("drm/amd/display: use low clocks for no plane
configs")' introduced a change that set low clock values for DCN31 and
DCN32. As a result of these changes, DC started to spam the log with the
following warning:

------------[ cut here ]------------
WARNING: CPU: 8 PID: 1486 at
drivers/gpu/drm/amd/amdgpu/../display/dc/dcn20/dcn20_dccg.c:58
dccg2_update_dpp_dto+0x3f/0xf0 [amdgpu]
[..]
CPU: 8 PID: 1486 Comm: kms_atomic Tainted: G W 5.18.0+ #1
RIP: 0010:dccg2_update_dpp_dto+0x3f/0xf0 [amdgpu]
RSP: 0018:ffffbbd8025334d0 EFLAGS: 00010206
RAX: 00000000000001ee RBX: ffffa02c87dd3de0 RCX: 00000000000a7f80
RDX: 000000000007dec3 RSI: 0000000000000000 RDI: ffffa02c87dd3de0
RBP: ffffbbd8025334e8 R08: 0000000000000001 R09: 0000000000000005
R10: 00000000000331a0 R11: ffffffffc0b03d80 R12: ffffa02ca576d000
R13: ffffa02cd02c0000 R14: 00000000001453bc R15: ffffa02cdc280000
[..]
dcn20_update_clocks_update_dpp_dto+0x4e/0xa0 [amdgpu]
dcn32_update_clocks+0x5d9/0x650 [amdgpu]
dcn20_prepare_bandwidth+0x49/0x100 [amdgpu]
dcn30_prepare_bandwidth+0x63/0x80 [amdgpu]
dc_commit_state_no_check+0x39d/0x13e0 [amdgpu]
dc_commit_streams+0x1f9/0x3b0 [amdgpu]
dc_commit_state+0x37/0x120 [amdgpu]
amdgpu_dm_atomic_commit_tail+0x5e5/0x2520 [amdgpu]
? _raw_spin_unlock_irqrestore+0x1f/0x40
? down_trylock+0x2c/0x40
? vprintk_emit+0x186/0x2c0
? vprintk_default+0x1d/0x20
? vprintk+0x4e/0x60

We can easily trigger this issue by using a 4k@120 or a 2k@165 and
running some of the kms_atomic tests. This warning is triggered because
the per-pipe clock update is not happening; this commit fixes this issue
by ensuring that DPPCLK is updated when calculating the watermark and
dlg is invoked.

Fixes: 2641c7b78081 ("drm/amd/display: use low clocks for no plane configs")
Reported-by: Mark Broadworth <mark.broadworth@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drivers/gpu/drm/amd/display/dc/dml/dcn31/dcn31_fpu.c
drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c