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References: <20220914201049.3508104-1-han.xu@nxp.com>
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From:   Fabio Estevam <festevam@gmail.com>
Date:   Wed, 14 Sep 2022 17:51:16 -0300
Message-ID: <CAOMZO5AGxXqF8Q6jhfr7vbZmQd6MU4SzFpj5XQG7cPtmdFrFVQ@mail.gmail.com>
Subject: Re: [PATCH] clk: imx: imx6sx: remove the SET_RATE_PARENT flag for
 QSPI clocks
To:     Han Xu <han.xu@nxp.com>
Cc:     Abel Vesa <abelvesa@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        NXP Linux Team <linux-imx@nxp.com>,
        "open list:NXP i.MX CLOCK DRIVERS" <linux-clk@vger.kernel.org>,
        "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" 
        <linux-arm-kernel@lists.infradead.org>,
        open list <linux-kernel@vger.kernel.org>,
        miquel.raynal@bootlin.com, linux-mtd@lists.infradead.org
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Hi Han Xu,

On Wed, Sep 14, 2022 at 5:11 PM Han Xu <han.xu@nxp.com> wrote:
>
> There is no dedicate parent clock for QSPI so SET_RATE_PARENT flag
> should not be used. For instance, the default parent clock for QSPI is
> pll2_bus, which is also the parent clock for quite a few modules, such
> as MMDC, once GPMI NAND set clock rate for EDO5 mode can cause system
> hang due to pll2_bus rate changed.

Thanks a lot for your patch.

This fixes the kernel hang issue on a custom imx6sx board with NAND without the
need of using the workaround found in the NXP kernel:

https://source.codeaurora.org/external/imx/linux-imx/commit/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c?h=lf-5.15.y&id=d03eb99c393f8732f70a1d7d29a3b9c42cccbe48

Tested-by: Fabio Estevam <festevam@denx.de>