diff options
| author | Marek Vasut <marex@denx.de> | 2012-08-24 04:56:27 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2012-08-27 18:36:53 +0200 |
| commit | 41682e03d4fdc947dbd22725d70f222cc7746852 (patch) | |
| tree | 3fa67108671a8be3cb7b806cedc9f3816ab8bca0 /drivers/spi/spi-mxs.c | |
| parent | mxs/spi: Restart the block after unsuccessful transfer (diff) | |
| download | linux-41682e03d4fdc947dbd22725d70f222cc7746852.tar.xz linux-41682e03d4fdc947dbd22725d70f222cc7746852.zip | |
mxs/spi: Fix misuse of init_completion
The init_completion() call does reinit not only the variable carrying
the flag that the completion finished, but also initialized the
waitqueue associated with the completion. On the contrary, the
INIT_COMPLETION() call only reinits the flag.
In case there was anything still stuck in the waitqueue, subsequent call
to init_completion() would be able to create possible race condition. This
patch uses the proper function and moves init_completion() into .probe() call
of the driver, to be issued only once.
Note that such scenario is impossible, since two threads can never enter the
mxs_spi_txrx_dma(), since whole this section is protected by mutex in SPI core.
This by no means allows this issue to exit though.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chris Ball <cjb@laptop.org>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'drivers/spi/spi-mxs.c')
| -rw-r--r-- | drivers/spi/spi-mxs.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/spi/spi-mxs.c b/drivers/spi/spi-mxs.c index 447f917fe66f..4e7801dd571a 100644 --- a/drivers/spi/spi-mxs.c +++ b/drivers/spi/spi-mxs.c @@ -230,7 +230,7 @@ static int mxs_spi_txrx_dma(struct mxs_spi *spi, int cs, return -EINVAL; } - init_completion(&spi->c); + INIT_COMPLETION(spi->c); if (*first) pio |= BM_SSP_CTRL0_LOCK_CS; @@ -549,6 +549,8 @@ static int __devinit mxs_spi_probe(struct platform_device *pdev) ssp->devid = devid; ssp->dma_channel = dma_channel; + init_completion(&spi->c); + ret = devm_request_irq(&pdev->dev, irq_err, mxs_ssp_irq_handler, 0, DRIVER_NAME, ssp); if (ret) |