spi: fix resource leak for drivers without .remove callback

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>

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 22679c8645db4a6e3532cded88a96f81551407a4..6b1e7637197622837368aa6e21dedaf8a0a805bf 100644 (file)
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -405,9 +405,11 @@ 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;
 }
@@ -415,9 +417,10 @@ 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;
@@ -442,10 +445,8 @@ 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);