On Tue, Feb 09, 2021 at 06:58:55PM +0100, Jernej Skrabec wrote:
Over the year I got plenty of reports of troubles with H6 HDMI signal. Sometimes monitor flickers, sometimes there was no image at all and sometimes it didn't play well with AVR.
It turns out there are multiple issues. Patch 1 fixes clock issue, which didn't adjust parent rate, even if it is allowed to do so. Patch 2 adds polarity config in tcon1. This is seemingly not needed for pre-HDMI2 controllers, although BSP drivers set it accordingly every time. It turns out that HDMI2 controllers often don't work with monitors if polarity is not set correctly. Patch 3 always set clock rate for HDMI controller. Patch 4 fixes H6 HDMI PHY settings. Patch 5 fixes comment and clock rate limit (wrong reasoning).
Please take a look.
Best regards, Jernej
Changes from v2:
- use clk_hw_can_set_rate_parent() directly instead of checking flags
Changes from v1:
- collected Chen-Yu tags (except on replaced patch 4)
- Added some comments in patch 2
- Replaced patch 4 (see commit log for explanation)
Applied patches 2-5, thanks Maxime