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>
diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
index 9a64c3f..595b62c 100644
--- a/drivers/spi/spi-altera.c
+++ b/drivers/spi/spi-altera.c
@@ -219,7 +219,7 @@
platform_set_drvdata(pdev, hw);
/* setup the state for the bitbang driver */
- hw->bitbang.master = spi_master_get(master);
+ hw->bitbang.master = master;
if (!hw->bitbang.master)
return err;
hw->bitbang.chipselect = altera_spi_chipsel;
diff --git a/drivers/spi/spi-ath79.c b/drivers/spi/spi-ath79.c
index 37bad95..821bf7a 100644
--- a/drivers/spi/spi-ath79.c
+++ b/drivers/spi/spi-ath79.c
@@ -231,7 +231,7 @@
master->num_chipselect = pdata->num_chipselect;
}
- sp->bitbang.master = spi_master_get(master);
+ sp->bitbang.master = master;
sp->bitbang.chipselect = ath79_spi_chipselect;
sp->bitbang.txrx_word[SPI_MODE_0] = ath79_spi_txrx_mode0;
sp->bitbang.setup_transfer = spi_bitbang_setup_transfer;
diff --git a/drivers/spi/spi-au1550.c b/drivers/spi/spi-au1550.c
index 1d00d9b3..e06400a 100644
--- a/drivers/spi/spi-au1550.c
+++ b/drivers/spi/spi-au1550.c
@@ -775,7 +775,7 @@
hw = spi_master_get_devdata(master);
- hw->master = spi_master_get(master);
+ hw->master = master;
hw->pdata = dev_get_platdata(&pdev->dev);
hw->dev = &pdev->dev;
diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
index 8c11355..0056623 100644
--- a/drivers/spi/spi-bitbang.c
+++ b/drivers/spi/spi-bitbang.c
@@ -414,10 +414,16 @@
* This routine registers the spi_master, which will process requests in a
* dedicated task, keeping IRQs unblocked most of the time. To stop
* processing those requests, call spi_bitbang_stop().
+ *
+ * On success, this routine will take a reference to master. 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.
*/
int spi_bitbang_start(struct spi_bitbang *bitbang)
{
struct spi_master *master = bitbang->master;
+ int ret;
if (!master || !bitbang->chipselect)
return -EINVAL;
@@ -449,7 +455,11 @@
/* driver may get busy before register() returns, especially
* if someone registered boardinfo for devices
*/
- return spi_register_master(master);
+ ret = spi_register_master(spi_master_get(master));
+ if (ret)
+ spi_master_put(master);
+
+ return 0;
}
EXPORT_SYMBOL_GPL(spi_bitbang_start);
diff --git a/drivers/spi/spi-butterfly.c b/drivers/spi/spi-butterfly.c
index 5ed08e5..b1ecea2 100644
--- a/drivers/spi/spi-butterfly.c
+++ b/drivers/spi/spi-butterfly.c
@@ -225,7 +225,7 @@
master->bus_num = 42;
master->num_chipselect = 2;
- pp->bitbang.master = spi_master_get(master);
+ pp->bitbang.master = master;
pp->bitbang.chipselect = butterfly_chipselect;
pp->bitbang.txrx_word[SPI_MODE_0] = butterfly_txrx_word_mode0;
diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c
index 8fbfe24..af2bb73 100644
--- a/drivers/spi/spi-davinci.c
+++ b/drivers/spi/spi-davinci.c
@@ -916,7 +916,7 @@
if (ret)
goto unmap_io;
- dspi->bitbang.master = spi_master_get(master);
+ dspi->bitbang.master = master;
if (dspi->bitbang.master == NULL) {
ret = -ENODEV;
goto irq_free;
@@ -925,7 +925,7 @@
dspi->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(dspi->clk)) {
ret = -ENODEV;
- goto put_master;
+ goto irq_free;
}
clk_prepare_enable(dspi->clk);
@@ -1015,8 +1015,6 @@
free_clk:
clk_disable_unprepare(dspi->clk);
clk_put(dspi->clk);
-put_master:
- spi_master_put(master);
irq_free:
free_irq(dspi->irq, dspi);
unmap_io:
@@ -1024,7 +1022,7 @@
release_region:
release_mem_region(dspi->pbase, resource_size(r));
free_master:
- kfree(master);
+ spi_master_put(master);
err:
return ret;
}
@@ -1051,11 +1049,11 @@
clk_disable_unprepare(dspi->clk);
clk_put(dspi->clk);
- spi_master_put(master);
free_irq(dspi->irq, dspi);
iounmap(dspi->base);
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(dspi->pbase, resource_size(r));
+ spi_master_put(master);
return 0;
}
diff --git a/drivers/spi/spi-efm32.c b/drivers/spi/spi-efm32.c
index 7d84418..d428a40 100644
--- a/drivers/spi/spi-efm32.c
+++ b/drivers/spi/spi-efm32.c
@@ -347,7 +347,7 @@
ddata = spi_master_get_devdata(master);
- ddata->bitbang.master = spi_master_get(master);
+ ddata->bitbang.master = master;
ddata->bitbang.chipselect = efm32_spi_chipselect;
ddata->bitbang.setup_transfer = efm32_spi_setup_transfer;
ddata->bitbang.txrx_bufs = efm32_spi_txrx_bufs;
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 6cd07d1..d338b67 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -450,7 +450,7 @@
dspi = spi_master_get_devdata(master);
dspi->pdev = pdev;
- dspi->bitbang.master = spi_master_get(master);
+ dspi->bitbang.master = master;
dspi->bitbang.chipselect = dspi_chipselect;
dspi->bitbang.setup_transfer = dspi_setup_transfer;
dspi->bitbang.txrx_bufs = dspi_txrx_transfer;
diff --git a/drivers/spi/spi-gpio.c b/drivers/spi/spi-gpio.c
index 68b69fe..14c01b4 100644
--- a/drivers/spi/spi-gpio.c
+++ b/drivers/spi/spi-gpio.c
@@ -467,7 +467,7 @@
}
#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 @@
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 @@
/* 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;
}
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 15323d8..02d9f46 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -786,7 +786,7 @@
master->num_chipselect = num_cs;
spi_imx = spi_master_get_devdata(master);
- spi_imx->bitbang.master = spi_master_get(master);
+ spi_imx->bitbang.master = master;
for (i = 0; i < master->num_chipselect; i++) {
int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
diff --git a/drivers/spi/spi-lm70llp.c b/drivers/spi/spi-lm70llp.c
index 0759b5d..41c5765 100644
--- a/drivers/spi/spi-lm70llp.c
+++ b/drivers/spi/spi-lm70llp.c
@@ -222,7 +222,7 @@
/*
* SPI and bitbang hookup.
*/
- pp->bitbang.master = spi_master_get(master);
+ pp->bitbang.master = master;
pp->bitbang.chipselect = lm70_chipselect;
pp->bitbang.txrx_word[SPI_MODE_0] = lm70_txrx;
pp->bitbang.flags = SPI_3WIRE;
diff --git a/drivers/spi/spi-nuc900.c b/drivers/spi/spi-nuc900.c
index 47a68b4..e0c32bc 100644
--- a/drivers/spi/spi-nuc900.c
+++ b/drivers/spi/spi-nuc900.c
@@ -349,7 +349,7 @@
}
hw = spi_master_get_devdata(master);
- hw->master = spi_master_get(master);
+ hw->master = master;
hw->pdata = dev_get_platdata(&pdev->dev);
hw->dev = &pdev->dev;
@@ -435,7 +435,6 @@
kfree(hw->ioarea);
err_pdata:
spi_master_put(hw->master);
-
err_nomem:
return err;
}
diff --git a/drivers/spi/spi-oc-tiny.c b/drivers/spi/spi-oc-tiny.c
index 333cb1b..91c6685 100644
--- a/drivers/spi/spi-oc-tiny.c
+++ b/drivers/spi/spi-oc-tiny.c
@@ -306,7 +306,7 @@
platform_set_drvdata(pdev, hw);
/* setup the state for the bitbang driver */
- hw->bitbang.master = spi_master_get(master);
+ hw->bitbang.master = master;
if (!hw->bitbang.master)
return err;
hw->bitbang.setup_transfer = tiny_spi_setup_transfer;
diff --git a/drivers/spi/spi-ppc4xx.c b/drivers/spi/spi-ppc4xx.c
index 0ee53c2..c57740bb7 100644
--- a/drivers/spi/spi-ppc4xx.c
+++ b/drivers/spi/spi-ppc4xx.c
@@ -396,7 +396,7 @@
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 @@
free_irq(hw->irqnum, hw);
iounmap(hw->regs);
free_gpios(hw);
+ spi_master_put(master);
return 0;
}
diff --git a/drivers/spi/spi-s3c24xx.c b/drivers/spi/spi-s3c24xx.c
index ce318d9..c9cfdfa 100644
--- a/drivers/spi/spi-s3c24xx.c
+++ b/drivers/spi/spi-s3c24xx.c
@@ -524,7 +524,7 @@
hw = spi_master_get_devdata(master);
memset(hw, 0, sizeof(struct s3c24xx_spi));
- hw->master = spi_master_get(master);
+ hw->master = master;
hw->pdata = pdata = dev_get_platdata(&pdev->dev);
hw->dev = &pdev->dev;
diff --git a/drivers/spi/spi-sh-sci.c b/drivers/spi/spi-sh-sci.c
index 8eefeb6..38eb24d 100644
--- a/drivers/spi/spi-sh-sci.c
+++ b/drivers/spi/spi-sh-sci.c
@@ -133,7 +133,7 @@
sp->info = dev_get_platdata(&dev->dev);
/* setup spi bitbang adaptor */
- sp->bitbang.master = spi_master_get(master);
+ sp->bitbang.master = master;
sp->bitbang.master->bus_num = sp->info->bus_num;
sp->bitbang.master->num_chipselect = sp->info->num_chipselect;
sp->bitbang.chipselect = sh_sci_spi_chipselect;
diff --git a/drivers/spi/spi-sirf.c b/drivers/spi/spi-sirf.c
index a1f21b7..592b4af 100644
--- a/drivers/spi/spi-sirf.c
+++ b/drivers/spi/spi-sirf.c
@@ -632,7 +632,7 @@
if (ret)
goto free_master;
- sspi->bitbang.master = spi_master_get(master);
+ sspi->bitbang.master = master;
sspi->bitbang.chipselect = spi_sirfsoc_chipselect;
sspi->bitbang.setup_transfer = spi_sirfsoc_setup_transfer;
sspi->bitbang.txrx_bufs = spi_sirfsoc_transfer;
diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c
index 0bf1b2c..ec3a83f 100644
--- a/drivers/spi/spi-xilinx.c
+++ b/drivers/spi/spi-xilinx.c
@@ -372,7 +372,7 @@
master->mode_bits = SPI_CPOL | SPI_CPHA;
xspi = spi_master_get_devdata(master);
- xspi->bitbang.master = spi_master_get(master);
+ xspi->bitbang.master = master;
xspi->bitbang.chipselect = xilinx_spi_chipselect;
xspi->bitbang.setup_transfer = xilinx_spi_setup_transfer;
xspi->bitbang.txrx_bufs = xilinx_spi_txrx_bufs;