From: Marek Vasut Date: Fri, 24 Aug 2012 02:56:27 +0000 (+0200) Subject: mxs/spi: Fix misuse of init_completion X-Git-Tag: firefly_0821_release~3680^2~1943^2~1^3~7 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=41682e03d4fdc947dbd22725d70f222cc7746852;p=firefly-linux-kernel-4.4.55.git 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 Cc: Chris Ball Cc: Shawn Guo Cc: Mark Brown Cc: Fabio Estevam Signed-off-by: Mark Brown --- 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)