spi/mxs: Fix device remove function
The call sequence spi_alloc_master/spi_register_master/spi_unregister_master
is complete; it reduces the device reference count to zero, which results in
device memory being freed. The remove function accesses the freed memory after
the call to spi_unregister_master(), _and_ it calls spi_master_put on the freed
memory.
Acquire a reference to the SPI master device and release it after cleanup is
complete (with the existing spi_master_put) to solve the problem.
Also, the device subsystem ensures that the remove function is only called once,
and resets device driver data to NULL. Remove the unnecessaary calls to
platform_set_drvdata().
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/spi/spi-mxs.c b/drivers/spi/spi-mxs.c
index 4e7801d..10d34eb 100644
--- a/drivers/spi/spi-mxs.c
+++ b/drivers/spi/spi-mxs.c
@@ -586,7 +586,6 @@
return 0;
out_free_dma:
- platform_set_drvdata(pdev, NULL);
dma_release_channel(ssp->dmach);
clk_disable_unprepare(ssp->clk);
out_master_free:
@@ -600,14 +599,12 @@
struct mxs_spi *spi;
struct mxs_ssp *ssp;
- master = platform_get_drvdata(pdev);
+ master = spi_master_get(platform_get_drvdata(pdev));
spi = spi_master_get_devdata(master);
ssp = &spi->ssp;
spi_unregister_master(master);
- platform_set_drvdata(pdev, NULL);
-
dma_release_channel(ssp->dmach);
clk_disable_unprepare(ssp->clk);