linux-stable.git/drivers/gpu/drm/amd/display/dc/dce, branch linux-5.15.y

drm/amd/display: Properly disable scaling on DCE6

2025-10-19T14:21:42+00:00

[ Upstream commit a7dc87f3448bea5ebe054f14e861074b9c289c65 ]

SCL_SCALER_ENABLE can be used to enable/disable the scaler
on DCE6. Program it to 0 when scaling isn't used, 1 when used.
Additionally, clear some other registers when scaling is
disabled and program the SCL_UPDATE register as recommended.

This fixes visible glitches for users whose BIOS sets up a
mode with scaling at boot, which DC was unable to clean up.

Fixes: b70aaf5586f2 ("drm/amd/display: dce_transform: add DCE6 specific macros,functions")
Reviewed-by: Alex Deucher 
Signed-off-by: Timur Kristóf 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amd/display: Properly clear SCL_*_FILTER_CONTROL on DCE6

2025-10-19T14:21:42+00:00

[ Upstream commit c0aa7cf49dd6cb302fe28e7183992b772cb7420c ]

Previously, the code would set a bit field which didn't exist
on DCE6 so it would be effectively a no-op.

Fixes: b70aaf5586f2 ("drm/amd/display: dce_transform: add DCE6 specific macros,functions")
Reviewed-by: Alex Deucher 
Signed-off-by: Timur Kristóf 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amd/display: Add missing DCE6 SCL_HORZ_FILTER_INIT* SRIs

2025-10-19T14:21:42+00:00

[ Upstream commit d60f9c45d1bff7e20ecd57492ef7a5e33c94a37c ]

Without these, it's impossible to program these registers.

Fixes: 102b2f587ac8 ("drm/amd/display: dce_transform: DCE6 Scaling Horizontal Filter Init (v2)")
Reviewed-by: Alex Deucher 
Signed-off-by: Timur Kristóf 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amd/display: Don't warn when missing DCE encoder caps

2025-09-09T16:50:17+00:00

[ Upstream commit 8246147f1fbaed522b8bcc02ca34e4260747dcfb ]

On some GPUs the VBIOS just doesn't have encoder caps,
or maybe not for every encoder.

This isn't really a problem and it's handled well,
so let's not litter the logs with it.

Signed-off-by: Timur Kristóf 
Acked-by: Alex Deucher 
Reviewed-by: Rodrigo Siqueira 
Reviewed-by: Alex Hung 
Signed-off-by: Alex Deucher 
(cherry picked from commit 33e0227ee96e62d034781e91f215e32fd0b1d512)
Signed-off-by: Sasha Levin

drm/amd/display: Use DC_LOG_DC in the trasform pixel function

2023-05-24T16:36:43+00:00

[ Upstream commit 7222f5841ff49709ca666b05ff336776e0664a20 ]

[Why & How]
DC now uses a new commit sequence which is more robust since it
addresses cases where we need to reorganize pipes based on planes and
other parameters. As a result, this new commit sequence reset the DC
state by cleaning plane states and re-creating them accordingly with the
need. For this reason, the dce_transform_set_pixel_storage_depth can be
invoked after a plane state is destroyed and before its re-creation. In
this situation and on DCE devices, DC will hit a condition that will
trigger a dmesg log that looks like this:

Console: switching to colour frame buffer device 240x67
------------[ cut here ]------------
[..]
Hardware name: System manufacturer System Product Name/PRIME X370-PRO, BIOS 5603 07/28/2020
RIP: 0010:dce_transform_set_pixel_storage_depth+0x3f8/0x480 [amdgpu]
[..]
RSP: 0018:ffffc9000202b850 EFLAGS: 00010293
RAX: ffffffffa081d100 RBX: ffff888110790000 RCX: 000000000000000c
RDX: ffff888100bedbf8 RSI: 0000000000001a50 RDI: ffff88810463c900
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000007
R10: 0000000000000001 R11: 0000000000000f00 R12: ffff88810f500010
R13: ffff888100bedbf8 R14: ffff88810f515688 R15: 0000000000000000
FS:  00007ff0159249c0(0000) GS:ffff88840e940000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff01528e550 CR3: 0000000002a10000 CR4: 00000000003506e0
Call Trace:
 
 ? dm_write_reg_func+0x21/0x80 [amdgpu 340dadd3f7c8cf4be11cf0bdc850245e99abe0e8]
 dc_stream_set_dither_option+0xfb/0x130 [amdgpu 340dadd3f7c8cf4be11cf0bdc850245e99abe0e8]
 amdgpu_dm_crtc_configure_crc_source+0x10b/0x190 [amdgpu 340dadd3f7c8cf4be11cf0bdc850245e99abe0e8]
 amdgpu_dm_atomic_commit_tail+0x20a8/0x2a90 [amdgpu 340dadd3f7c8cf4be11cf0bdc850245e99abe0e8]
 ? free_unref_page_commit+0x98/0x170
 ? free_unref_page+0xcc/0x150
 commit_tail+0x94/0x120
 drm_atomic_helper_commit+0x10f/0x140
 drm_atomic_commit+0x94/0xc0
 ? drm_plane_get_damage_clips.cold+0x1c/0x1c
 drm_client_modeset_commit_atomic+0x203/0x250
 drm_client_modeset_commit_locked+0x56/0x150
 drm_client_modeset_commit+0x21/0x40
 drm_fb_helper_lastclose+0x42/0x70
 amdgpu_driver_lastclose_kms+0xa/0x10 [amdgpu 340dadd3f7c8cf4be11cf0bdc850245e99abe0e8]
 drm_release+0xda/0x110
 __fput+0x89/0x240
 task_work_run+0x5c/0x90
 do_exit+0x333/0xae0
 do_group_exit+0x2d/0x90
 __x64_sys_exit_group+0x14/0x20
 do_syscall_64+0x5b/0x80
 ? exit_to_user_mode_prepare+0x1e/0x140
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7ff016ceaca1
Code: Unable to access opcode bytes at RIP 0x7ff016ceac77.
RSP: 002b:00007ffe7a2357e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ff016e15a00 RCX: 00007ff016ceaca1
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffff78 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff016e15a00
R13: 0000000000000000 R14: 00007ff016e1aee8 R15: 00007ff016e1af00
 

Since this issue only happens in a transition state on DC, this commit
replace BREAK_TO_DEBUGGER with DC_LOG_DC.

Reviewed-by: Harry Wentland 
Acked-by: Qingqing Zhuo 
Signed-off-by: Rodrigo Siqueira 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amd/display: Fix pixel clock programming

2022-09-05T08:30:11+00:00

[ Upstream commit 04fb918bf421b299feaee1006e82921d7d381f18 ]

[Why]
Some pixel clock values could cause HDMI TMDS SSCPs to be misaligned
between different HDMI lanes when using YCbCr420 10-bit pixel format.

BIOS functions for transmitter/encoder control take pixel clock in kHz
increments, whereas the function for setting the pixel clock is in 100Hz
increments. Setting pixel clock to a value that is not on a kHz boundary
will cause the issue.

[How]
Round pixel clock down to nearest kHz in 10/12-bpc cases.

Reviewed-by: Aric Cyr 
Acked-by: Brian Chang 
Signed-off-by: Ilya Bakoulin 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amd/display: Check if modulo is 0 before dividing.

2022-06-14T16:36:23+00:00

[ Upstream commit 49947b906a6bd9668eaf4f9cf691973c25c26955 ]

[How & Why]
If a value of 0 is read, then this will cause a divide-by-0 panic.

Reviewed-by: Martin Leung 
Acked-by: Qingqing Zhuo 
Signed-off-by: David Galiffi 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amd/display: fix empty debug macros

2021-09-23T19:58:21+00:00

Using an empty macro expansion as a conditional expression
produces a W=1 warning:

drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dce_aux.c: In function 'dce_aux_transfer_with_retries':
drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dce_aux.c:775:156: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
  775 |                                                                 "dce_aux_transfer_with_retries: AUX_RET_SUCCESS: AUX_TRANSACTION_REPLY_I2C_OVER_AUX_DEFER");
      |                                                                                                                                                            ^
drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dce_aux.c:783:155: error: suggest braces around empty body in an 'if' statement [-Werror=empty-body]
  783 |                                                                 "dce_aux_transfer_with_retries: AUX_RET_SUCCESS: AUX_TRANSACTION_REPLY_I2C_OVER_AUX_NACK");
      |                                                                                                                                                           ^

Expand it to "do { } while (0)" instead to make the expression
more robust and avoid the warning.

Fixes: 56aca2309301 ("drm/amd/display: Add AUX I2C tracing.")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Alex Deucher

drm/amd/display: Get backlight from PWM if DMCU is not initialized

2021-09-16T13:56:23+00:00

On Carrizo/Stoney systems we set backlight through panel_cntl, i.e.
directly via the PWM registers, if DMCU is not initialized. We
always read it back through ABM registers which leads to a
mismatch and forces atomic_commit to program the backlight
each time.

Instead make sure we use the same logic for backlight readback,
i.e. read it from panel_cntl if DMCU is not initialized.

We also need to remove some extraneous and incorrect calculations
at the end of dce_get_16_bit_backlight_from_pwm.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/1666
Cc: stable@vger.kernel.org

Reviewed-by: Josip Pavic 
Acked-by: Mikita Lipski 
Signed-off-by: Harry Wentland 
Tested-by: Daniel Wheeler 
Signed-off-by: Alex Deucher

drm/amd/display: use do-while-0 for DC_TRACE_LEVEL_MESSAGE()

2021-08-09T19:44:40+00:00

Building with W=1 complains about an empty 'else' statement, so use the
usual do-nothing-while-0 loop to quieten this warning.

../drivers/gpu/drm/amd/amdgpu/../display/dc/dce/dmub_psr.c:113:53: warning: suggest braces around empty body in an 'else' statement [-Wempty-body]
  113 |                                 *state, retry_count);

Fixes: b30eda8d416c ("drm/amd/display: Add ETW log to dmub_psr_get_state")
Signed-off-by: Randy Dunlap 
Cc: Wyatt Wood 
Cc: Alex Deucher 
Cc: Christian König 
Cc: "Pan, Xinhui" 
Cc: Harry Wentland 
Cc: Leo Li 
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie 
Cc: Daniel Vetter 
Signed-off-by: Alex Deucher