drm/amd/display: Avoid reading LTTPR caps in non-LTTPR mode.

[Why]
LTTPR capable devices on the DisplayPort path may assume that
extended LTTPR AUX timeouts will be used after LTTPR capabilities
are read.

When DPTX operates in non-LTTPR mode, AUX timeouts are not
extended and this can result in AUX transactions timing out.

[How]
Use shared helper function to determine LTTPR mode and do not
read LTTPR capabilities in non-LTTPR mode.

Reviewed-by: Mustapha Ghaddar <[email protected]>
Reviewed-by: Meenakshikumar Somasundaram <[email protected]>
Reviewed-by: Jun Lei <[email protected]>
Acked-by: Hamza Mahfooz <[email protected]>
Signed-off-by: Jimmy Kizito <[email protected]>
Tested-by: Daniel Wheeler <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

0 files changed, 0 insertions, 0 deletions