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spi: Cleanup on failure of initial setup

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Commit c7299fea67 ("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 c7299fea67, 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: c7299fea67 ("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>
This commit is contained in:
Lukas Wunner
2021-05-27 23:10:56 +02:00
committed by Mark Brown
parent 13817d466e
commit 2ec6f20b33
5 changed files with 54 additions and 19 deletions
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33
drivers/spi/spi-omap2-mcspi.c
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@@ -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;