diff options
Diffstat (limited to 'drivers/spi/spidev.c')
| -rw-r--r-- | drivers/spi/spidev.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c index 2833fd772a2..e5e0cfed5e3 100644 --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -228,7 +228,6 @@ static int spidev_message(struct spidev_data *spidev, * We walk the array of user-provided transfers, using each one * to initialize a kernel version of the same transfer. */ - mutex_lock(&spidev->buf_lock); buf = spidev->buffer; total = 0; for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; @@ -296,14 +295,12 @@ static int spidev_message(struct spidev_data *spidev, status = total; done: - mutex_unlock(&spidev->buf_lock); kfree(k_xfers); return status; } -static int -spidev_ioctl(struct inode *inode, struct file *filp, - unsigned int cmd, unsigned long arg) +static long +spidev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { int err = 0; int retval = 0; @@ -341,6 +338,14 @@ spidev_ioctl(struct inode *inode, struct file *filp, if (spi == NULL) return -ESHUTDOWN; + /* use the buffer lock here for triple duty: + * - prevent I/O (from us) so calling spi_setup() is safe; + * - prevent concurrent SPI_IOC_WR_* from morphing + * data fields while SPI_IOC_RD_* reads them; + * - SPI_IOC_MESSAGE needs the buffer locked "normally". + */ + mutex_lock(&spidev->buf_lock); + switch (cmd) { /* read requests */ case SPI_IOC_RD_MODE: @@ -456,6 +461,8 @@ spidev_ioctl(struct inode *inode, struct file *filp, kfree(ioc); break; } + + mutex_unlock(&spidev->buf_lock); spi_dev_put(spi); return retval; } @@ -533,7 +540,7 @@ static struct file_operations spidev_fops = { */ .write = spidev_write, .read = spidev_read, - .ioctl = spidev_ioctl, + .unlocked_ioctl = spidev_ioctl, .open = spidev_open, .release = spidev_release, }; |