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| author | Axel Lin <axel.lin@ingics.com> | 2013-09-10 11:43:41 +0400 |
|---|---|---|
| committer | Mark Brown <broonie@linaro.org> | 2013-09-17 15:56:14 +0400 |
| commit | 94c69f765f1b4a658d96905ec59928e3e3e07e6a (patch) | |
| tree | cfa1fffd3906bff17eed2e9771f2c33fd55877af /drivers/spi/spi-ppc4xx.c | |
| parent | 272b98c6455f00884f0350f775c5342358ebb73f (diff) | |
| download | linux-94c69f765f1b4a658d96905ec59928e3e3e07e6a.tar.xz | |
spi: bitbang: Let spi_bitbang_start() take a reference to master
Many drivers that use bitbang library have a leak on probe error paths.
This is because once a spi_master_get() call succeeds, we need an additional
spi_master_put() call to free the memory.
Fix this issue by moving the code taking a reference to master to
spi_bitbang_start(), so spi_bitbang_start() will take a reference to master on
success. With this change, the caller is responsible for calling
spi_bitbang_stop() to decrement the reference and spi_master_put() as
counterpart of spi_alloc_master() to prevent a memory leak.
So now we have below patten for drivers using bitbang library:
probe:
spi_alloc_master -> Init reference count to 1
spi_bitbang_start -> Increment reference count
remove:
spi_bitbang_stop -> Decrement reference count
spi_master_put -> Decrement reference count (reference count reaches 0)
Fixup all users accordingly.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Suggested-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Acked-by: Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'drivers/spi/spi-ppc4xx.c')
| -rw-r--r-- | drivers/spi/spi-ppc4xx.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/spi/spi-ppc4xx.c b/drivers/spi/spi-ppc4xx.c index 0ee53c25ba58..c57740bb70d3 100644 --- a/drivers/spi/spi-ppc4xx.c +++ b/drivers/spi/spi-ppc4xx.c @@ -396,7 +396,7 @@ static int spi_ppc4xx_of_probe(struct platform_device *op) master->dev.of_node = np; platform_set_drvdata(op, master); hw = spi_master_get_devdata(master); - hw->master = spi_master_get(master); + hw->master = master; hw->dev = dev; init_completion(&hw->done); @@ -558,6 +558,7 @@ static int spi_ppc4xx_of_remove(struct platform_device *op) free_irq(hw->irqnum, hw); iounmap(hw->regs); free_gpios(hw); + spi_master_put(master); return 0; } |