spi: Cleanup on failure of initial setup

Commit c7299fea6769 ("spi: Fix spi device unregister flow") changed the
SPI core's behavior if the ->setup() hook returns an error upon adding
an spi_device:  Before, the ->cleanup() hook was invoked to free any
allocations that were made by ->setup().  With the commit, that's no
longer the case, so the ->setup() hook is expected to free the
allocations itself.

I've identified 5 drivers which depend on the old behavior and am fixing
them up hereinafter: spi-bitbang.c spi-fsl-spi.c spi-omap-uwire.c
spi-omap2-mcspi.c spi-pxa2xx.c

Importantly, ->setup() is not only invoked on spi_device *addition*:
It may subsequently be called to *change* SPI parameters.  If changing
these SPI parameters fails, freeing memory allocations would be wrong.
That should only be done if the spi_device is finally destroyed.
I am therefore using a bool "initial_setup" in 4 of the affected drivers
to differentiate between the invocation on *adding* the spi_device and
any subsequent invocations: spi-bitbang.c spi-fsl-spi.c spi-omap-uwire.c
spi-omap2-mcspi.c

In spi-pxa2xx.c, it seems the ->setup() hook can only fail on spi_device
addition, not any subsequent calls.  It therefore doesn't need the bool.

It's worth noting that 5 other drivers already perform a cleanup if the
->setup() hook fails.  Before c7299fea6769, they caused a double-free
if ->setup() failed on spi_device addition.  Since the commit, they're
fine.  These drivers are: spi-mpc512x-psc.c spi-pl022.c spi-s3c64xx.c
spi-st-ssc4.c spi-tegra114.c

(spi-pxa2xx.c also already performs a cleanup, but only in one of
several error paths.)

Fixes: c7299fea6769 ("spi: Fix spi device unregister flow")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Saravana Kannan <saravanak@google.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> # pxa2xx
Link: https://lore.kernel.org/r/f76a0599469f265b69c371538794101fa37b5536.1622149321.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 5e59ba075bc7..8ee0cc071777 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1254,6 +1254,8 @@ static int setup_cs(struct spi_device *spi, struct chip_data *chip,
 		chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH;
 
 		err = gpiod_direction_output(gpiod, !chip->gpio_cs_inverted);
+		if (err)
+			gpiod_put(chip->gpiod_cs);
 	}
 
 	return err;
@@ -1267,6 +1269,7 @@ static int setup(struct spi_device *spi)
 	struct driver_data *drv_data =
 		spi_controller_get_devdata(spi->controller);
 	uint tx_thres, tx_hi_thres, rx_thres;
+	int err;
 
 	switch (drv_data->ssp_type) {
 	case QUARK_X1000_SSP:
@@ -1413,7 +1416,11 @@ static int setup(struct spi_device *spi)
 	if (drv_data->ssp_type == CE4100_SSP)
 		return 0;
 
-	return setup_cs(spi, chip, chip_info);
+	err = setup_cs(spi, chip, chip_info);
+	if (err)
+		kfree(chip);
+
+	return err;
 }
 
 static void cleanup(struct spi_device *spi)