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References: <20210423034247.992052-1-art@khadas.com> <20210423114735.GA5507@sirena.org.uk>
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From:   Art Nikpal <email2tema@gmail.com>
Date:   Sat, 24 Apr 2021 08:08:57 +0800
Message-ID: <CAKaHn9LC19cduyrwxkDRAdM5pjgSPBCdZUjsEMgGqS7yVQS1-g@mail.gmail.com>
Subject: Re: [PATCH] SPI: meson-spifc add missed calls to remove function
To:     Mark Brown <broonie@kernel.org>
Cc:     Neil Armstrong <narmstrong@baylibre.com>,
        Kevin Hilman <khilman@baylibre.com>, jbrunet@baylibre.com,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        dri-devel@lists.freedesktop.org, linux-spi@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
        Christian Hewitt <christianshewitt@gmail.com>,
        Artem Lapkin <art@khadas.com>, nick@khadas.com,
        Gouwa Wang <gouwa@khadas.com>
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> I would expect the driver to unregister the controller at the start of
> the remove function, suspend doesn't really make sense here

It's strange - But without spi_master_suspend i have randomly stucks
when i try unload this module - as was written before
i was test it (load/unload module in loop) and for me suspend make sense here

If anybody has another solution - or real problem not here - please
help to find the right way!

PS: i have another way for solve this problem (may be it can help us
fix problem in kernel)

# before unload module need
echo -n spi0.0 > /sys/bus/spi/drivers/spi-nor/unbind
# after unbind driver we can unload module without problem
rmmod spi_meson_spifc # can stuck without unbind driver before ...


On Fri, Apr 23, 2021 at 7:48 PM Mark Brown <broonie@kernel.org> wrote:
>
> On Fri, Apr 23, 2021 at 11:42:47AM +0800, Artem Lapkin wrote:
> > Problem: rmmod meson_gx_mmc - not stable without spi_master_suspend call
> > and we can get stuck when try unload this module
>
> > +++ b/drivers/spi/spi-meson-spifc.c
> > @@ -359,6 +359,7 @@ static int meson_spifc_remove(struct platform_device *pdev)
> >       struct spi_master *master = platform_get_drvdata(pdev);
> >       struct meson_spifc *spifc = spi_master_get_devdata(master);
> >
> > +     spi_master_suspend(master);
> >       pm_runtime_get_sync(&pdev->dev);
> >       clk_disable_unprepare(spifc->clk);
> >       pm_runtime_disable(&pdev->dev);
>
> I would expect the driver to unregister the controller at the start of
> the remove function, suspend doesn't really make sense here.