Re: [PATCH] Staging: comedi: Fixed long line lengths in drivers.c

From: Joe Perches
Date: Mon May 17 2010 - 08:05:09 EST


On Mon, 2010-05-17 at 18:48 +0800, Mark wrote:
> This patch clears up some long line length warnings in drivers.c found by
> checkpatch
>
> Signed-off-by: Mark Rankilor <reodge@xxxxxxxxx>

Hi Mark.

> diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
> index 4a29ed7..7da4625 100644
> --- a/drivers/staging/comedi/drivers.c
> +++ b/drivers/staging/comedi/drivers.c
> @@ -442,7 +444,10 @@ int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
> unsigned i;
> for (i = 0; i < async->n_buf_pages; ++i) {
> if (async->buf_page_list[i].virt_addr) {
> - clear_bit(PG_reserved, &(virt_to_page(async->buf_page_list[i].virt_addr)->flags));

It's better to not just fix the checkpatch errors by simply
wrapping the code, but rather to factor the code for clarity.

Using a temporary would fix a lot of these long line problems.

Moving these into static alloc/free functions would help as well.

Perhaps something like:
---
drivers/staging/comedi/drivers.c | 188 ++++++++++++++++++--------------------
1 files changed, 87 insertions(+), 101 deletions(-)

diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index 4a29ed7..bdbbe8e 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -420,6 +420,91 @@ static inline unsigned long kvirt_to_kva(unsigned long adr)
return kva;
}

+static void free_buf_page_list(struct comedi_device *dev,
+ struct comedi_subdevice *s)
+{
+ int i;
+ struct comedi_async *async = s->async;
+ struct comedi_buf_page *bp = async->buf_page_list;
+
+ if (!async->buf_page_list)
+ return;
+
+ for (i = 0; i < async->n_buf_pages; ++i) {
+ if (bp->virt_addr) {
+ clear_bit(PG_reserved,
+ &virt_to_page(bp->virt_addr)->flags);
+ if (s->async_dma_dir != DMA_NONE) {
+ dma_free_coherent(dev->hw_dev, PAGE_SIZE,
+ bp->virt_addr, bp->dma_addr);
+ } else {
+ free_page((unsigned long)bp->virt_addr);
+ }
+ }
+ bp++;
+ }
+ vfree(async->buf_page_list);
+ async->buf_page_list = NULL;
+ async->n_buf_pages = 0;
+}
+
+static int alloc_buf_page_list(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ unsigned long new_size)
+{
+ unsigned i = 0;
+ struct comedi_async *async = s->async;
+ unsigned n_pages = new_size >> PAGE_SHIFT;
+ unsigned bp_size = sizeof(struct comedi_buf_page) * n_pages;
+ struct page **pages = NULL;
+
+ /* allocate new buffer */
+ if (!new_size)
+ return 0;
+
+ async->buf_page_list = vmalloc(bp_size);
+ if (!async->buf_page_list)
+ return -ENOMEM;
+ memset(async->buf_page_list, 0, bp_size);
+ pages = vmalloc(sizeof(struct page *) * n_pages);
+ if (pages) {
+ struct comedi_buf_page *bp = async->buf_page_list;
+ for (i = 0; i < n_pages; i++) {
+ if (s->async_dma_dir != DMA_NONE) {
+ bp->virt_addr =
+ dma_alloc_coherent(dev->hw_dev,
+ PAGE_SIZE,
+ &bp->dma_addr,
+ GFP_KERNEL |
+ __GFP_COMP);
+ } else {
+ bp->virt_addr = (void *)
+ get_zeroed_page(GFP_KERNEL);
+ }
+ if (bp->virt_addr == NULL) {
+ vfree(pages);
+ free_buf_page_list(dev, s);
+ return -ENOMEM;
+ }
+
+ set_bit(PG_reserved,
+ &virt_to_page(bp->virt_addr)->flags);
+ pages[i] = virt_to_page(bp->virt_addr);
+ bp++;
+ }
+ }
+
+ async->prealloc_buf = vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE);
+ vfree(pages);
+ if (!async->prealloc_buf) {
+ free_buf_page_list(dev, s);
+ return -ENOMEM;
+ }
+ async->n_buf_pages = n_pages;
+ async->prealloc_bufsz = new_size;
+ return 0;
+}
+
int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
unsigned long new_size)
{
@@ -438,108 +523,9 @@ int comedi_buf_alloc(struct comedi_device *dev, struct comedi_subdevice *s,
async->prealloc_buf = NULL;
async->prealloc_bufsz = 0;
}
- if (async->buf_page_list) {
- unsigned i;
- for (i = 0; i < async->n_buf_pages; ++i) {
- if (async->buf_page_list[i].virt_addr) {
- clear_bit(PG_reserved, &(virt_to_page(async->buf_page_list[i].virt_addr)->flags));
- if (s->async_dma_dir != DMA_NONE) {
- dma_free_coherent(dev->hw_dev,
- PAGE_SIZE,
- async->
- buf_page_list
- [i].virt_addr,
- async->
- buf_page_list
- [i].dma_addr);
- } else {
- free_page((unsigned long)
- async->buf_page_list[i].
- virt_addr);
- }
- }
- }
- vfree(async->buf_page_list);
- async->buf_page_list = NULL;
- async->n_buf_pages = 0;
- }
- /* allocate new buffer */
- if (new_size) {
- unsigned i = 0;
- unsigned n_pages = new_size >> PAGE_SHIFT;
- struct page **pages = NULL;
-
- async->buf_page_list =
- vmalloc(sizeof(struct comedi_buf_page) * n_pages);
- if (async->buf_page_list) {
- memset(async->buf_page_list, 0,
- sizeof(struct comedi_buf_page) * n_pages);
- pages = vmalloc(sizeof(struct page *) * n_pages);
- }
- if (pages) {
- for (i = 0; i < n_pages; i++) {
- if (s->async_dma_dir != DMA_NONE) {
- async->buf_page_list[i].virt_addr =
- dma_alloc_coherent(dev->hw_dev,
- PAGE_SIZE,
- &async->
- buf_page_list
- [i].dma_addr,
- GFP_KERNEL |
- __GFP_COMP);
- } else {
- async->buf_page_list[i].virt_addr =
- (void *)
- get_zeroed_page(GFP_KERNEL);
- }
- if (async->buf_page_list[i].virt_addr == NULL)
- break;
-
- set_bit(PG_reserved,
- &(virt_to_page(async->buf_page_list[i].virt_addr)->flags));
- pages[i] = virt_to_page(async->buf_page_list[i].virt_addr);
- }
- }
- if (i == n_pages) {
- async->prealloc_buf =
- vmap(pages, n_pages, VM_MAP, PAGE_KERNEL_NOCACHE);
- }
- vfree(pages);
-
- if (async->prealloc_buf == NULL) {
- /* Some allocation failed above. */
- if (async->buf_page_list) {
- for (i = 0; i < n_pages; i++) {
- if (async->buf_page_list[i].virt_addr ==
- NULL) {
- break;
- }
- clear_bit(PG_reserved, &(virt_to_page(async->buf_page_list[i].virt_addr)->flags));
- if (s->async_dma_dir != DMA_NONE) {
- dma_free_coherent(dev->hw_dev,
- PAGE_SIZE,
- async->
- buf_page_list
- [i].virt_addr,
- async->
- buf_page_list
- [i].dma_addr);
- } else {
- free_page((unsigned long)
- async->buf_page_list
- [i].virt_addr);
- }
- }
- vfree(async->buf_page_list);
- async->buf_page_list = NULL;
- }
- return -ENOMEM;
- }
- async->n_buf_pages = n_pages;
- }
- async->prealloc_bufsz = new_size;

- return 0;
+ free_buf_page_list(dev, s);
+ return alloc_buf_page_list(dev, s, new_size);
}

/* munging is applied to data by core as it passes between user


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