diff options
Diffstat (limited to 'drivers/spi/spidev.c')
| -rw-r--r-- | drivers/spi/spidev.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c index 799337f7fde..ddbe1a5e970 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> @@ -167,14 +168,14 @@ spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos) mutex_lock(&spidev->buf_lock); status = spidev_sync_read(spidev, count); - if (status == 0) { + if (status > 0) { unsigned long missing; - missing = copy_to_user(buf, spidev->buffer, count); - if (count && missing == count) + missing = copy_to_user(buf, spidev->buffer, status); + if (missing == status) status = -EFAULT; else - status = count - missing; + status = status - missing; } mutex_unlock(&spidev->buf_lock); @@ -200,8 +201,6 @@ spidev_write(struct file *filp, const char __user *buf, missing = copy_from_user(spidev->buffer, buf, count); if (missing == 0) { status = spidev_sync_write(spidev, count); - if (status == 0) - status = count; } else status = -EFAULT; mutex_unlock(&spidev->buf_lock); @@ -466,6 +465,7 @@ 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) { @@ -491,6 +491,7 @@ 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; } |