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    Subject[PATCH 4.19 155/346] spi: fix resource leak for drivers without .remove callback
    Date
    From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

    [ Upstream commit 440408dbadfe47a615afd0a0a4a402e629be658a ]

    Consider an spi driver with a .probe but without a .remove callback (e.g.
    rtc-ds1347). The function spi_drv_probe() is called to bind a device and
    so dev_pm_domain_attach() is called. As there is no remove callback
    spi_drv_remove() isn't called at unbind time however and so calling
    dev_pm_domain_detach() is missed and the pm domain keeps active.

    To fix this always use both spi_drv_probe() and spi_drv_remove() and
    make them handle the respective callback not being set. This has the
    side effect that for a (hypothetical) driver that has neither .probe nor
    remove the clk and pm domain setup is done.

    Fixes: 33cf00e57082 ("spi: attach/detach SPI device to the ACPI power domain")
    Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
    Link: https://lore.kernel.org/r/20201119161604.2633521-1-u.kleine-koenig@pengutronix.de
    Signed-off-by: Mark Brown <broonie@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/spi/spi.c | 19 ++++++++++---------
    1 file changed, 10 insertions(+), 9 deletions(-)

    diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
    index fbc5444bd9cbd..7dabbc82b6463 100644
    --- a/drivers/spi/spi.c
    +++ b/drivers/spi/spi.c
    @@ -362,9 +362,11 @@ static int spi_drv_probe(struct device *dev)
    if (ret)
    return ret;

    - ret = sdrv->probe(spi);
    - if (ret)
    - dev_pm_domain_detach(dev, true);
    + if (sdrv->probe) {
    + ret = sdrv->probe(spi);
    + if (ret)
    + dev_pm_domain_detach(dev, true);
    + }

    return ret;
    }
    @@ -372,9 +374,10 @@ static int spi_drv_probe(struct device *dev)
    static int spi_drv_remove(struct device *dev)
    {
    const struct spi_driver *sdrv = to_spi_driver(dev->driver);
    - int ret;
    + int ret = 0;

    - ret = sdrv->remove(to_spi_device(dev));
    + if (sdrv->remove)
    + ret = sdrv->remove(to_spi_device(dev));
    dev_pm_domain_detach(dev, true);

    return ret;
    @@ -399,10 +402,8 @@ int __spi_register_driver(struct module *owner, struct spi_driver *sdrv)
    {
    sdrv->driver.owner = owner;
    sdrv->driver.bus = &spi_bus_type;
    - if (sdrv->probe)
    - sdrv->driver.probe = spi_drv_probe;
    - if (sdrv->remove)
    - sdrv->driver.remove = spi_drv_remove;
    + sdrv->driver.probe = spi_drv_probe;
    + sdrv->driver.remove = spi_drv_remove;
    if (sdrv->shutdown)
    sdrv->driver.shutdown = spi_drv_shutdown;
    return driver_register(&sdrv->driver);
    --
    2.27.0


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