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| author | Axel Lin <axel.lin@ingics.com> | 2013-09-10 09:43:41 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@linaro.org> | 2013-09-17 13:56:14 +0200 |
| commit | 94c69f765f1b4a658d96905ec59928e3e3e07e6a (patch) | |
| tree | cfa1fffd3906bff17eed2e9771f2c33fd55877af /drivers/spi/spi-gpio.c | |
| parent | Linux 3.12-rc1 (diff) | |
| download | linux-94c69f765f1b4a658d96905ec59928e3e3e07e6a.tar.xz linux-94c69f765f1b4a658d96905ec59928e3e3e07e6a.zip | |
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-gpio.c')
| -rw-r--r-- | drivers/spi/spi-gpio.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c index 68b69fec13a9..14c01b44ca7a 100644 --- a/drivers/spi/spi-gpio.c +++ b/drivers/spi/spi-gpio.c @@ -467,7 +467,7 @@ static int spi_gpio_probe(struct platform_device *pdev) } #endif - spi_gpio->bitbang.master = spi_master_get(master); + spi_gpio->bitbang.master = master; spi_gpio->bitbang.chipselect = spi_gpio_chipselect; if ((master_flags & (SPI_MASTER_NO_TX | SPI_MASTER_NO_RX)) == 0) { @@ -486,7 +486,6 @@ static int spi_gpio_probe(struct platform_device *pdev) status = spi_bitbang_start(&spi_gpio->bitbang); if (status < 0) { - spi_master_put(spi_gpio->bitbang.master); gpio_free: if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) gpio_free(SPI_MISO_GPIO); @@ -510,13 +509,13 @@ static int spi_gpio_remove(struct platform_device *pdev) /* stop() unregisters child devices too */ status = spi_bitbang_stop(&spi_gpio->bitbang); - spi_master_put(spi_gpio->bitbang.master); if (SPI_MISO_GPIO != SPI_GPIO_NO_MISO) gpio_free(SPI_MISO_GPIO); if (SPI_MOSI_GPIO != SPI_GPIO_NO_MOSI) gpio_free(SPI_MOSI_GPIO); gpio_free(SPI_SCK_GPIO); + spi_master_put(spi_gpio->bitbang.master); return status; } |