]> www.infradead.org Git - users/hch/misc.git/commit
drm/ast: astdp: Fix timeout for enabling video signal
authorThomas Zimmermann <tzimmermann@suse.de>
Mon, 27 Jan 2025 13:44:14 +0000 (14:44 +0100)
committerThomas Zimmermann <tzimmermann@suse.de>
Tue, 28 Jan 2025 13:31:50 +0000 (14:31 +0100)
commitfd39c41bcd82d5ebaaebadb944eab5598c668a90
treef771523d11a3e72e43e319cbbf5600f29a3c405f
parente0f63bc68f59d281e2d06e596f6c1bd9382a15cd
drm/ast: astdp: Fix timeout for enabling video signal

The ASTDP transmitter sometimes takes up to 1 second for enabling the
video signal, while the timeout is only 200 msec. This results in a
kernel error message. Increase the timeout to 1 second. An example
of the error message is shown below.

[  697.084433] ------------[ cut here ]------------
[  697.091115] ast 0000:02:00.0: [drm] drm_WARN_ON(!__ast_dp_wait_enable(ast, enabled))
[  697.091233] WARNING: CPU: 1 PID: 160 at drivers/gpu/drm/ast/ast_dp.c:232 ast_dp_set_enable+0x123/0x140 [ast]
[...]
[  697.272469] RIP: 0010:ast_dp_set_enable+0x123/0x140 [ast]
[...]
[  697.415283] Call Trace:
[  697.420727]  <TASK>
[  697.425908]  ? show_trace_log_lvl+0x196/0x2c0
[  697.433304]  ? show_trace_log_lvl+0x196/0x2c0
[  697.440693]  ? drm_atomic_helper_commit_modeset_enables+0x30a/0x470
[  697.450115]  ? ast_dp_set_enable+0x123/0x140 [ast]
[  697.458059]  ? __warn.cold+0xaf/0xca
[  697.464713]  ? ast_dp_set_enable+0x123/0x140 [ast]
[  697.472633]  ? report_bug+0x134/0x1d0
[  697.479544]  ? handle_bug+0x58/0x90
[  697.486127]  ? exc_invalid_op+0x13/0x40
[  697.492975]  ? asm_exc_invalid_op+0x16/0x20
[  697.500224]  ? preempt_count_sub+0x14/0xc0
[  697.507473]  ? ast_dp_set_enable+0x123/0x140 [ast]
[  697.515377]  ? ast_dp_set_enable+0x123/0x140 [ast]
[  697.523227]  drm_atomic_helper_commit_modeset_enables+0x30a/0x470
[  697.532388]  drm_atomic_helper_commit_tail+0x58/0x90
[  697.540400]  ast_mode_config_helper_atomic_commit_tail+0x30/0x40 [ast]
[  697.550009]  commit_tail+0xfe/0x1d0
[  697.556547]  drm_atomic_helper_commit+0x198/0x1c0

This is a cosmetical problem. Enabling the video signal still works
even with the error message. The problem has always been present, but
only recent versions of the ast driver warn about missing the timeout.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 4e29cc7c5c67 ("drm/ast: astdp: Replace ast_dp_set_on_off()")
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v6.13+
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250127134423.84266-1-tzimmermann@suse.de
drivers/gpu/drm/ast/ast_dp.c