Re: [PATCH V2] nvmem: add explicit config option to read OF fixed cells

From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
To: "Rafał Miłecki" <zajec5@gmail.com>,
	"Srinivas Kandagatla" <srinivas.kandagatla@linaro.org>
Cc: "Miquel Raynal" <miquel.raynal@bootlin.com>,
	"Richard Weinberger" <richard@nod.at>,
	"Vignesh Raghavendra" <vigneshr@ti.com>,
	"Hector Martin" <marcan@marcan.st>,
	"Sven Peter" <sven@svenpeter.dev>,
	"Alyssa Rosenzweig" <alyssa@rosenzweig.io>,
	"Shawn Guo" <shawnguo@kernel.org>,
	"Sascha Hauer" <s.hauer@pengutronix.de>,
	"Pengutronix Kernel Team" <kernel@pengutronix.de>,
	"Fabio Estevam" <festevam@gmail.com>,
	"NXP Linux Team" <linux-imx@nxp.com>,
	"Neil Armstrong" <neil.armstrong@linaro.org>,
	"Kevin Hilman" <khilman@baylibre.com>,
	"Jerome Brunet" <jbrunet@baylibre.com>,
	"Martin Blumenstingl" <martin.blumenstingl@googlemail.com>,
	"Claudiu Beznea" <claudiu.beznea@microchip.com>,
	"Matthias Brugger" <matthias.bgg@gmail.com>,
	"Andy Gross" <agross@kernel.org>,
	"Bjorn Andersson" <andersson@kernel.org>,
	"Konrad Dybcio" <konrad.dybcio@linaro.org>,
	"Heiko Stuebner" <heiko@sntech.de>,
	"Orson Zhai" <orsonzhai@gmail.com>,
	"Baolin Wang" <baolin.wang@linux.alibaba.com>,
	"Chunyan Zhang" <zhang.lyra@gmail.com>,
	"Maxime Coquelin" <mcoquelin.stm32@gmail.com>,
	"Alexandre Torgue" <alexandre.torgue@foss.st.com>,
	"Vincent Shih" <vincent.sunplus@gmail.com>,
	"Chen-Yu Tsai" <wens@csie.org>,
	"Jernej Skrabec" <jernej.skrabec@gmail.com>,
	"Samuel Holland" <samuel@sholland.org>,
	"Kunihiko Hayashi" <hayashi.kunihiko@socionext.com>,
	"Masami Hiramatsu" <mhiramat@kernel.org>,
	"Michal Simek" <michal.simek@xilinx.com>,
	"Alessandro Zummo" <a.zummo@towertech.it>,
	"Alexandre Belloni" <alexandre.belloni@bootlin.com>,
	"Evgeniy Polyakov" <zbr@ioremap.net>,
	linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
	asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
	linux-amlogic@lists.infradead.org,
	linux-mediatek@lists.infradead.org,
	linux-arm-msm@vger.kernel.org,
	linux-rockchip@lists.infradead.org,
	linux-stm32@st-md-mailman.stormreply.com,
	linux-sunxi@lists.linux.dev, linux-rtc@vger.kernel.org,
	"Rafał Miłecki" <rafal@milecki.pl>
Subject: Re: [PATCH V2] nvmem: add explicit config option to read OF fixed cells
Date: Fri, 24 Feb 2023 14:13:59 +0100	[thread overview]
Message-ID: <c17f94a6-c710-f80e-c2af-9e450f144157@collabora.com> (raw)
In-Reply-To: <20230224072903.20945-1-zajec5@gmail.com>

Il 24/02/23 08:29, Rafał Miłecki ha scritto:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> NVMEM subsystem looks for fixed NVMEM cells (specified in DT) by
> default. This behaviour made sense in early days before adding support
> for dynamic cells.
> 
> With every new supported NVMEM device with dynamic cells current
> behaviour becomes non-optimal. It results in unneeded iterating over DT
> nodes and may result in false discovery of cells (depending on used DT
> properties).
> 
> This behaviour has actually caused a problem already with the MTD
> subsystem. MTD subpartitions were incorrectly treated as NVMEM cells.
> 
> Also with upcoming support for NVMEM layouts no new binding or driver
> should support fixed cells defined in device node.
> 
> Solve this by modifying drivers for bindings that support specifying
> fixed NVMEM cells in DT. Make them explicitly tell NVMEM subsystem to
> read cells from DT.
> 
> It wasn't clear (to me) if rtc and w1 code actually uses fixed cells. I
> enabled them to don't risk any breakage.
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> [for drivers/nvmem/meson-{efuse,mx-efuse}.c]
> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

[for mtk-efuse.c, nvmem/core.c, nvmem-provider.h]
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

[MT8192, MT8195 Chromebooks]
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>


_______________________________________________
Linux-rockchip mailing list
Linux-rockchip@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-rockchip