Re: [PATCH v4 0/5] Pinephone video out fixes (flipping between two frames)

From: Frank Oltmanns <frank@oltmanns.dev>
To: Michael Turquette <mturquette@baylibre.com>,
	 Stephen Boyd <sboyd@kernel.org>,  Chen-Yu Tsai <wens@csie.org>,
	 Jernej Skrabec <jernej.skrabec@gmail.com>,
	 Samuel Holland <samuel@sholland.org>,
	 Maxime Ripard <mripard@kernel.org>
Cc: "Guido Günther" <agx@sigxcpu.org>,
	"Purism Kernel Team" <kernel@puri.sm>,
	"Ondrej Jirman" <megi@xff.cz>,
	"Neil Armstrong" <neil.armstrong@linaro.org>,
	"Jessica Zhang" <quic_jesszhan@quicinc.com>,
	"Sam Ravnborg" <sam@ravnborg.org>,
	"Maarten Lankhorst" <maarten.lankhorst@linux.intel.com>,
	"Thomas Zimmermann" <tzimmermann@suse.de>,
	"David Airlie" <airlied@gmail.com>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org,
	dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
	stable@vger.kernel.org, "Diego Roversi" <diegor@tiscali.it>,
	"Erico Nunes" <nunes.erico@gmail.com>
Subject: Re: [PATCH v4 0/5] Pinephone video out fixes (flipping between two frames)
Date: Wed, 03 Apr 2024 17:31:47 +0200	[thread overview]
Message-ID: <87frw2a2e4.fsf@oltmanns.dev> (raw)
In-Reply-To: <20240310-pinephone-pll-fixes-v4-0-46fc80c83637@oltmanns.dev> (Frank Oltmanns's message of "Sun, 10 Mar 2024 14:21:10 +0100")

Dear clk and sunxi-ng maintainers,

Patches 1-4 have been reviewed and there are no pending issues. If there
is something else you need me to do to get this applied, please let me
know.

Thanks,
  Frank

On 2024-03-10 at 14:21:10 +0100, Frank Oltmanns <frank@oltmanns.dev> wrote:
> 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.
>
> I very much appreciate your feedback!
>
> [1] https://gitlab.com/postmarketOS/pmaports/-/issues/805
>
> Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
> ---
> Changes in v4:
> - sunxi-ng: common: Address review comments.
> - Link to v3: https://lore.kernel.org/r/20240304-pinephone-pll-fixes-v3-0-94ab828f269a@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@oltmanns.dev
>
> 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@oltmanns.dev
>
> ---
> 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             | 19 +++++++++++++++++++
>  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, 54 insertions(+), 13 deletions(-)
> ---
> base-commit: dcb6c8ee6acc6c347caec1e73fb900c0f4ff9806
> change-id: 20231218-pinephone-pll-fixes-0ccdfde273e4
>
> Best regards,