diff options
Diffstat (limited to 'drivers/spi/spidev.c')
| -rw-r--r-- | drivers/spi/spidev.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c index f5b60c70389..e5e0cfed5e3 100644 --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -30,6 +30,7 @@ #include <linux/errno.h> #include <linux/mutex.h> #include <linux/slab.h> +#include <linux/smp_lock.h> #include <linux/spi/spi.h> #include <linux/spi/spidev.h> @@ -227,7 +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; @@ -295,14 +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; @@ -340,6 +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: @@ -455,6 +461,8 @@ spidev_ioctl(struct inode *inode, struct file *filp, kfree(ioc); break; } + + mutex_unlock(&spidev->buf_lock); spi_dev_put(spi); return retval; } @@ -464,6 +472,7 @@ static int spidev_open(struct inode *inode, struct file *filp) struct spidev_data *spidev; int status = -ENXIO; + lock_kernel(); mutex_lock(&device_list_lock); list_for_each_entry(spidev, &device_list, device_entry) { @@ -489,6 +498,7 @@ static int spidev_open(struct inode *inode, struct file *filp) pr_debug("spidev: nothing for minor %d\n", iminor(inode)); mutex_unlock(&device_list_lock); + unlock_kernel(); return status; } @@ -530,7 +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, }; @@ -573,7 +583,8 @@ static int spidev_probe(struct spi_device *spi) struct device *dev; spidev->devt = MKDEV(SPIDEV_MAJOR, minor); - dev = device_create(spidev_class, &spi->dev, spidev->devt, + dev = device_create_drvdata(spidev_class, &spi->dev, + spidev->devt, spidev, "spidev%d.%d", spi->master->bus_num, spi->chip_select); status = IS_ERR(dev) ? PTR_ERR(dev) : 0; @@ -583,7 +594,6 @@ static int spidev_probe(struct spi_device *spi) } if (status == 0) { set_bit(minor, minors); - spi_set_drvdata(spi, spidev); list_add(&spidev->device_entry, &device_list); } mutex_unlock(&device_list_lock); |