On some pinephones the video output sometimes freezes (flips between two frames) [1]. It seems to be that the reason for this behaviour is that PLL-MIPI is outside its limits, and the GPU is not running at a fixed rate.
In this patch series I propose the following changes: 1. sunxi-ng: Adhere to the following constraints given in the Allwinner A64 Manual regarding PLL-MIPI: * M/N <= 3 * (PLL_VIDEO0)/M >= 24MHz * 500MHz <= clockrate <= 1400MHz
2. Remove two operating points from the A64 DTS OPPs, so that the GPU runs at a fixed rate of 432 MHz.
Note, that when pinning the GPU to 432 MHz the issue [1] completely disappears for me. I've searched the BSP and could not find any indication that supports the idea of having the three OPPs. The only frequency I found in the BPSs for A64 is 432 MHz, which has also proven stable for me.
Another bigger change compared to the previous version is that I've removed the patch to adapt the XBD599 panel's timings to Allwinner A64's PLL-MIPI new constraints from this series. Mainly, because I'm currently evaluationg other options that may or may not work. (It may work at least until HDMI support is upstreamed.) I'll probably resend the patch at a later point in time.
I very much appreciate your feedback!
[1] https://gitlab.com/postmarketOS/pmaports/-/issues/805
Signed-off-by: Frank Oltmanns frank@oltmanns.dev --- Changes in v3: - dts: Pin GPU to 432 MHz. - nkm and a64: Move minimum and maximum rate handling to the common part of the sunxi-ng driver. - Removed st7703 patch from series. - Link to v2: https://lore.kernel.org/r/20240205-pinephone-pll-fixes-v2-0-96a46a2d8c9b@olt...
Changes in v2: - dts: Increase minimum GPU frequency to 192 MHz. - nkm and a64: Add minimum and maximum rate for PLL-MIPI. - nkm: Use the same approach for skipping invalid rates in ccu_nkm_find_best() as in ccu_nkm_find_best_with_parent_adj(). - nkm: Improve names for ratio struct members and hence get rid of describing comments. - nkm and a64: Correct description in the commit messages: M/N <= 3 - Remove patches for nm as they were not needed. - st7703: Rework the commit message to cover more background for the change. - Link to v1: https://lore.kernel.org/r/20231218-pinephone-pll-fixes-v1-0-e238b6ed6dc1@olt...
--- Frank Oltmanns (5): clk: sunxi-ng: common: Support minimum and maximum rate clk: sunxi-ng: a64: Set minimum and maximum rate for PLL-MIPI clk: sunxi-ng: nkm: Support constraints on m/n ratio and parent rate clk: sunxi-ng: a64: Add constraints on PLL-MIPI's n/m ratio and parent rate arm64: dts: allwinner: a64: Run GPU at 432 MHz
arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi | 8 -------- drivers/clk/sunxi-ng/ccu-sun50i-a64.c | 14 +++++++++----- drivers/clk/sunxi-ng/ccu_common.c | 15 +++++++++++++++ drivers/clk/sunxi-ng/ccu_common.h | 3 +++ drivers/clk/sunxi-ng/ccu_nkm.c | 21 +++++++++++++++++++++ drivers/clk/sunxi-ng/ccu_nkm.h | 2 ++ 6 files changed, 50 insertions(+), 13 deletions(-) --- base-commit: 216c1282dde38ca87ebdf1ccacee5a0682901574 change-id: 20231218-pinephone-pll-fixes-0ccdfde273e4
Best regards,