linux-stable.git/drivers/gpu/drm/amd/display, branch linux-6.17.y

drm/amd/display: Fix logical vs bitwise bug in get_embedded_panel_info_v2_1()

2025-12-18T12:59:58+00:00

[ Upstream commit 1a79482699b4d1e43948d14f0c7193dc1dcad858 ]

The .H_SYNC_POLARITY and .V_SYNC_POLARITY variables are 1 bit bitfields
of a u32.  The ATOM_HSYNC_POLARITY define is 0x2 and the
ATOM_VSYNC_POLARITY is 0x4.  When we do a bitwise negate of 0, 2, or 4
then the last bit is always 1 so this code always sets .H_SYNC_POLARITY
and .V_SYNC_POLARITY to true.

This code is instead intended to check if the ATOM_HSYNC_POLARITY or
ATOM_VSYNC_POLARITY flags are set and reverse the result.  In other
words, it's supposed to be a logical negate instead of a bitwise negate.

Fixes: ae79c310b1a6 ("drm/amd/display: Add DCE12 bios parser support")
Signed-off-by: Dan Carpenter 
Reviewed-by: Alex Hung 
Signed-off-by: Alex Deucher 
Signed-off-by: Sasha Levin

drm/amd/display: Increase EDID read retries

2025-12-06T21:27:39+00:00

commit 8ea902361734c87b82122f9c17830f168ebfc65a upstream.

[WHY]
When monitor is still booting EDID read can fail while DPCD read
is successful.  In this case no EDID data will be returned, and this
could happen for a while.

[HOW]
Increase number of attempts to read EDID in dm_helpers_read_local_edid()
to 25.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4672
Cc: Mario Limonciello 
Cc: Alex Deucher 
Reviewed-by: Alex Hung 
Signed-off-by: Mario Limonciello (AMD) 
Signed-off-by: Alex Hung 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher 
(cherry picked from commit a76d6f2c76c3abac519ba753e2723e6ffe8e461c)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Don't change brightness for disabled connectors

2025-12-06T21:27:39+00:00

commit 81f4d4ba509522596143fd5d7dc2fc3495296b0a upstream.

[WHY]
When a laptop lid is closed the connector is disabled but userspace
can still try to change brightness.  This doesn't work because the
panel is turned off. It will eventually time out, but there is a lot
of stutter along the way.

[How]
Iterate all connectors to check whether the matching one for the backlight
index is enabled.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4675
Cc: Mario Limonciello 
Cc: Alex Deucher 
Reviewed-by: Ray Wu 
Signed-off-by: Mario Limonciello (AMD) 
Signed-off-by: Alex Hung 
Signed-off-by: Alex Deucher 
(cherry picked from commit f6eeab30323d1174a4cc022e769d248fe8241304)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Check NULL before accessing

2025-12-06T21:27:39+00:00

commit 3ce62c189693e8ed7b3abe551802bbc67f3ace54 upstream.

[WHAT]
IGT kms_cursor_legacy's long-nonblocking-modeset-vs-cursor-atomic
fails with NULL pointer dereference. This can be reproduced with
both an eDP panel and a DP monitors connected.

 BUG: kernel NULL pointer dereference, address: 0000000000000000
 #PF: supervisor read access in kernel mode
 #PF: error_code(0x0000) - not-present page
 PGD 0 P4D 0
 Oops: Oops: 0000 [#1] SMP NOPTI
 CPU: 13 UID: 0 PID: 2960 Comm: kms_cursor_lega Not tainted
6.16.0-99-custom #8 PREEMPT(voluntary)
 Hardware name: AMD ........
 RIP: 0010:dc_stream_get_scanoutpos+0x34/0x130 [amdgpu]
 Code: 57 4d 89 c7 41 56 49 89 ce 41 55 49 89 d5 41 54 49
 89 fc 53 48 83 ec 18 48 8b 87 a0 64 00 00 48 89 75 d0 48 c7 c6 e0 41 30
 c2 <48> 8b 38 48 8b 9f 68 06 00 00 e8 8d d7 fd ff 31 c0 48 81 c3 e0 02
 RSP: 0018:ffffd0f3c2bd7608 EFLAGS: 00010292
 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffd0f3c2bd7668
 RDX: ffffd0f3c2bd7664 RSI: ffffffffc23041e0 RDI: ffff8b32494b8000
 RBP: ffffd0f3c2bd7648 R08: ffffd0f3c2bd766c R09: ffffd0f3c2bd7760
 R10: ffffd0f3c2bd7820 R11: 0000000000000000 R12: ffff8b32494b8000
 R13: ffffd0f3c2bd7664 R14: ffffd0f3c2bd7668 R15: ffffd0f3c2bd766c
 FS:  000071f631b68700(0000) GS:ffff8b399f114000(0000)
knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 0000000000000000 CR3: 00000001b8105000 CR4: 0000000000f50ef0
 PKRU: 55555554
 Call Trace:
 
 dm_crtc_get_scanoutpos+0xd7/0x180 [amdgpu]
 amdgpu_display_get_crtc_scanoutpos+0x86/0x1c0 [amdgpu]
 ? __pfx_amdgpu_crtc_get_scanout_position+0x10/0x10[amdgpu]
 amdgpu_crtc_get_scanout_position+0x27/0x50 [amdgpu]
 drm_crtc_vblank_helper_get_vblank_timestamp_internal+0xf7/0x400
 drm_crtc_vblank_helper_get_vblank_timestamp+0x1c/0x30
 drm_crtc_get_last_vbltimestamp+0x55/0x90
 drm_crtc_next_vblank_start+0x45/0xa0
 drm_atomic_helper_wait_for_fences+0x81/0x1f0
 ...

Cc: Mario Limonciello 
Cc: Alex Deucher 
Reviewed-by: Aurabindo Pillai 
Signed-off-by: Alex Hung 
Signed-off-by: Alex Deucher 
(cherry picked from commit 621e55f1919640acab25383362b96e65f2baea3c)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

Revert "drm/amd/display: Move setup_stream_attribute"

2025-12-06T21:27:34+00:00

commit 3126c9ccb4373d8758733c6699ba5ab93dbe5c9d upstream.

This reverts commit 2681bf4ae8d24df950138b8c9ea9c271cd62e414.

This results in a blank screen on the HDMI port on some systems.
Revert for now so as not to regress 6.18, can be addressed
in 6.19 once the issue is root caused.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4652
Cc: Sunpeng.Li@amd.com
Cc: ivan.lipski@amd.com
Signed-off-by: Alex Deucher 
(cherry picked from commit d0e9de7a81503cdde37fb2d37f1d102f9e0f38fb)
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Prevent Gating DTBCLK before It Is Properly Latched

2025-12-01T10:46:07+00:00

[ Upstream commit cfa0904a35fd0231f4d05da0190f0a22ed881cce ]

[why]
1. With allow_0_dtb_clk enabled, the time required to latch DTBCLK to 600 MHz
depends on the SMU. If DTBCLK is not latched to 600 MHz before set_mode completes,
gating DTBCLK causes the DP2 sink to lose its clock source.

2. The existing DTBCLK gating sequence ungates DTBCLK based on both pix_clk and ref_dtbclk,
but gates DTBCLK when either pix_clk or ref_dtbclk is zero.
pix_clk can be zero outside the set_mode sequence before DTBCLK is properly latched,
which can lead to DTBCLK being gated by mistake.

[how]
Consider both pixel_clk and ref_dtbclk when determining when it is safe to gate DTBCLK;
this is more accurate.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4701
Fixes: 5949e7c4890c ("drm/amd/display: Enable Dynamic DTBCLK Switch")
Reviewed-by: Charlene Liu 
Reviewed-by: Aurabindo Pillai 
Signed-off-by: Fangzhi Zuo 
Signed-off-by: Roman Li 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher 
(cherry picked from commit d04eb0c402780ca037b62a6aecf23b863545ebca)
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Insert dccg log for easy debug

2025-12-01T10:46:07+00:00

[ Upstream commit 35bcc9168f3ce6416cbf3f776758be0937f84cb3 ]

[why]
Log for sequence tracking

Reviewed-by: Ovidiu (Ovi) Bunea 
Reviewed-by: Yihan Zhu 
Signed-off-by: Charlene Liu 
Signed-off-by: Ivan Lipski 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher 
Stable-dep-of: cfa0904a35fd ("drm/amd/display: Prevent Gating DTBCLK before It Is Properly Latched")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Clear the CUR_ENABLE register on DCN20 on DPP5

2025-12-01T10:45:48+00:00

commit 5bab4c89390f32b2f491f49a151948cd226dd909 upstream.

[Why]
On DCN20 & DCN30, the 6th DPP's & HUBP's are powered on permanently and
cannot be power gated. Thus, when dpp_reset() is invoked for the DPP5,
while it's still powered on, the cached cursor_state
(dpp_base->pos.cur0_ctl.bits.cur0_enable)
and the actual state (CUR0_ENABLE) bit are unsycned. This can cause a
double cursor in full screen with non-native scaling.

[How]
Force disable cursor on DPP5 on plane powerdown for ASICs w/ 6 DPPs/HUBPs.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4673
Reviewed-by: Aric Cyr 
Signed-off-by: Ivan Lipski 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher 
(cherry picked from commit 79b3c037f972dcb13e325a8eabfb8da835764e15)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Fix pbn to kbps Conversion

2025-12-01T10:45:48+00:00

commit 1788ef30725da53face7e311cdf62ad65fababcd upstream.

[Why]
Existing routine has two conversion sequence,
pbn_to_kbps and kbps_to_pbn with margin.
Non of those has without-margin calculation.

kbps_to_pbn with margin conversion includes
fec overhead which has already been included in
pbn_div calculation with 0.994 factor considered.
It is a double counted fec overhead factor that causes
potential bw loss.

[How]
Add without-margin calculation.
Fix fec overhead double counted issue.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3735
Reviewed-by: Aurabindo Pillai 
Signed-off-by: Fangzhi Zuo 
Signed-off-by: Ivan Lipski 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher 
(cherry picked from commit e0dec00f3d05e8c0eceaaebfdca217f8d10d380c)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman

drm/amd/display: Move sleep into each retry for retrieve_link_cap()

2025-12-01T10:45:48+00:00

commit 71ad9054c1f241be63f9d11df8cbd0aa0352fe16 upstream.

[Why]
When a monitor is booting it's possible that it isn't ready to retrieve
link caps and this can lead to an EDID read failure:

```
[drm:retrieve_link_cap [amdgpu]] *ERROR* retrieve_link_cap: Read receiver caps dpcd data failed.
amdgpu 0000:c5:00.0: [drm] *ERROR* No EDID read.
```

[How]
Rather than msleep once and try a few times, msleep each time.  Should
be no changes for existing working monitors, but should correct reading
caps on a monitor that is slow to boot.

Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4672
Reviewed-by: Alex Hung 
Signed-off-by: Mario Limonciello (AMD) 
Signed-off-by: Ivan Lipski 
Tested-by: Dan Wheeler 
Signed-off-by: Alex Deucher 
(cherry picked from commit 669dca37b3348a447db04bbdcbb3def94d5997cc)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman