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staging: comedi: comedi_fops: cleanup comedi_mmap()

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Use comedi_dev_from_minor() to simplify the return -ENODEV tests.

Change the (foo == NULL) tests to simply (!foo).

Use a local variable to hold a pointer to the async->buf_page_list[]
when doing the remap_pfn_range(). This cleans up the ugly line breaks
for the page_to_pfn(virt_to_page(...) operation.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
H Hartley Sweeten 2012-12-19 15:45:12 -07:00 committed by Greg Kroah-Hartman
parent 401d99de5c
commit a52840a98b
1 changed files with 14 additions and 15 deletions
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29
drivers/staging/comedi/comedi_fops.c
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@ -1766,39 +1766,38 @@ static struct vm_operations_struct comedi_vm_ops = {
static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
{
const unsigned minor = iminor(file->f_dentry->d_inode);
struct comedi_async *async = NULL;
struct comedi_file_info *info = comedi_file_info_from_minor(minor);
struct comedi_device *dev = comedi_dev_from_minor(minor);
struct comedi_subdevice *s;
struct comedi_async *async;
unsigned long start = vma->vm_start;
unsigned long size;
int n_pages;
int i;
int retval;
struct comedi_subdevice *s;
struct comedi_file_info *info = comedi_file_info_from_minor(minor);
struct comedi_device *dev;
if (info == NULL)
return -ENODEV;
dev = info->device;
if (dev == NULL)
if (!dev)
return -ENODEV;
mutex_lock(&dev->mutex);
if (!dev->attached) {
DPRINTK("no driver configured on comedi%i\n", dev->minor);
retval = -ENODEV;
goto done;
}
if (vma->vm_flags & VM_WRITE)
s = comedi_write_subdevice(info);
else
s = comedi_read_subdevice(info);
if (s == NULL) {
if (!s) {
retval = -EINVAL;
goto done;
}
async = s->async;
if (async == NULL) {
if (!async) {
retval = -EINVAL;
goto done;
}
@ -1821,11 +1820,11 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma)
n_pages = size >> PAGE_SHIFT;
for (i = 0; i < n_pages; ++i) {
struct comedi_buf_page *buf = &async->buf_page_list[i];
if (remap_pfn_range(vma, start,
page_to_pfn(virt_to_page
(async->buf_page_list
[i].virt_addr)), PAGE_SIZE,
PAGE_SHARED)) {
page_to_pfn(virt_to_page(buf->virt_addr)),
PAGE_SIZE, PAGE_SHARED)) {
retval = -EAGAIN;
goto done;
}