Commit 2ec6f20b authored by Lukas Wunner's avatar Lukas Wunner Committed by Mark Brown

spi: Cleanup on failure of initial setup

Commit c7299fea ("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 c7299fea, 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: c7299fea ("spi: Fix spi device unregister flow")
Signed-off-by: default avatarLukas 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.deSigned-off-by: default avatarMark Brown <broonie@kernel.org>
parent 13817d46
......@@ -184,6 +184,8 @@ int spi_bitbang_setup(struct spi_device *spi)
{
struct spi_bitbang_cs *cs = spi->controller_state;
struct spi_bitbang *bitbang;
bool initial_setup = false;
int retval;
bitbang = spi_master_get_devdata(spi->master);
......@@ -192,22 +194,30 @@ int spi_bitbang_setup(struct spi_device *spi)
if (!cs)
return -ENOMEM;
spi->controller_state = cs;
initial_setup = true;
}
/* per-word shift register access, in hardware or bitbanging */
cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
if (!cs->txrx_word)
return -EINVAL;
if (!cs->txrx_word) {
retval = -EINVAL;
goto err_free;
}
if (bitbang->setup_transfer) {
int retval = bitbang->setup_transfer(spi, NULL);
retval = bitbang->setup_transfer(spi, NULL);
if (retval < 0)
return retval;
goto err_free;
}
dev_dbg(&spi->dev, "%s, %u nsec/bit\n", __func__, 2 * cs->nsecs);
return 0;
err_free:
if (initial_setup)
kfree(cs);
return retval;
}
EXPORT_SYMBOL_GPL(spi_bitbang_setup);
......
......@@ -440,6 +440,7 @@ static int fsl_spi_setup(struct spi_device *spi)
{
struct mpc8xxx_spi *mpc8xxx_spi;
struct fsl_spi_reg __iomem *reg_base;
bool initial_setup = false;
int retval;
u32 hw_mode;
struct spi_mpc8xxx_cs *cs = spi_get_ctldata(spi);
......@@ -452,6 +453,7 @@ static int fsl_spi_setup(struct spi_device *spi)
if (!cs)
return -ENOMEM;
spi_set_ctldata(spi, cs);
initial_setup = true;
}
mpc8xxx_spi = spi_master_get_devdata(spi->master);
......@@ -475,6 +477,8 @@ static int fsl_spi_setup(struct spi_device *spi)
retval = fsl_spi_setup_transfer(spi, NULL);
if (retval < 0) {
cs->hw_mode = hw_mode; /* Restore settings */
if (initial_setup)
kfree(cs);
return retval;
}
......
......@@ -424,15 +424,22 @@ static int uwire_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
static int uwire_setup(struct spi_device *spi)
{
struct uwire_state *ust = spi->controller_state;
bool initial_setup = false;
int status;
if (ust == NULL) {
ust = kzalloc(sizeof(*ust), GFP_KERNEL);
if (ust == NULL)
return -ENOMEM;
spi->controller_state = ust;
initial_setup = true;
}
return uwire_setup_transfer(spi, NULL);
status = uwire_setup_transfer(spi, NULL);
if (status && initial_setup)
kfree(ust);
return status;
}
static void uwire_cleanup(struct spi_device *spi)
......
......@@ -1032,8 +1032,22 @@ static void omap2_mcspi_release_dma(struct spi_master *master)
}
}
static void omap2_mcspi_cleanup(struct spi_device *spi)
{
struct omap2_mcspi_cs *cs;
if (spi->controller_state) {
/* Unlink controller state from context save list */
cs = spi->controller_state;
list_del(&cs->node);
kfree(cs);
}
}
static int omap2_mcspi_setup(struct spi_device *spi)
{
bool initial_setup = false;
int ret;
struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
struct omap2_mcspi_regs *ctx = &mcspi->ctx;
......@@ -1051,35 +1065,28 @@ static int omap2_mcspi_setup(struct spi_device *spi)
spi->controller_state = cs;
/* Link this to context save list */
list_add_tail(&cs->node, &ctx->cs);
initial_setup = true;
}
ret = pm_runtime_get_sync(mcspi->dev);
if (ret < 0) {
pm_runtime_put_noidle(mcspi->dev);
if (initial_setup)
omap2_mcspi_cleanup(spi);
return ret;
}
ret = omap2_mcspi_setup_transfer(spi, NULL);
if (ret && initial_setup)
omap2_mcspi_cleanup(spi);
pm_runtime_mark_last_busy(mcspi->dev);
pm_runtime_put_autosuspend(mcspi->dev);
return ret;
}
static void omap2_mcspi_cleanup(struct spi_device *spi)
{
struct omap2_mcspi_cs *cs;
if (spi->controller_state) {
/* Unlink controller state from context save list */
cs = spi->controller_state;
list_del(&cs->node);
kfree(cs);
}
}
static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data)
{
struct omap2_mcspi *mcspi = data;
......
......@@ -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)
......
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