* [PATCH V2 linux-next] staging: media: atomisp: kmap() can't fail
@ 2017-04-26 18:44 Fabian Frederick
2017-04-26 23:02 ` Alan Cox
0 siblings, 1 reply; 2+ messages in thread
From: Fabian Frederick @ 2017-04-26 18:44 UTC (permalink / raw)
To: Mauro Carvalho Chehab, Greg Kroah-Hartman, Alan Cox
Cc: Jan Kara, linux-kernel, fabf
There's no need to check kmap() return value because it won't fail.
If it's highmem mapping, it will receive virtual address
or a new one; if it's lowmem, all kernel pages are already being mapped.
(Thanks to Jan Kara for explanations)
Signed-off-by: Fabian Frederick <fabf@skynet.be>
---
V2: Verbose description (suggested by Greg Kroah-Hartman)
drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm.c | 19 ++-----------------
1 file changed, 2 insertions(+), 17 deletions(-)
diff --git a/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm.c b/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm.c
index 151abf0..7d2f8d9 100644
--- a/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm.c
+++ b/drivers/staging/media/atomisp/pci/atomisp2/hmm/hmm.c
@@ -328,15 +328,7 @@ static int load_and_flush_by_kmap(ia_css_ptr virt, void *data, unsigned int byte
idx = (virt - bo->start) >> PAGE_SHIFT;
offset = (virt - bo->start) - (idx << PAGE_SHIFT);
- src = (char *)kmap(bo->page_obj[idx].page);
- if (!src) {
- dev_err(atomisp_dev,
- "kmap buffer object page failed: "
- "pg_idx = %d\n", idx);
- return -EINVAL;
- }
-
- src += offset;
+ src = (char *)kmap(bo->page_obj[idx].page) + offset;
if ((bytes + offset) >= PAGE_SIZE) {
len = PAGE_SIZE - offset;
@@ -533,14 +525,7 @@ int hmm_set(ia_css_ptr virt, int c, unsigned int bytes)
idx = (virt - bo->start) >> PAGE_SHIFT;
offset = (virt - bo->start) - (idx << PAGE_SHIFT);
- des = (char *)kmap(bo->page_obj[idx].page);
- if (!des) {
- dev_err(atomisp_dev,
- "kmap buffer object page failed: "
- "pg_idx = %d\n", idx);
- return -EINVAL;
- }
- des += offset;
+ des = (char *)kmap(bo->page_obj[idx].page) + offset;
if ((bytes + offset) >= PAGE_SIZE) {
len = PAGE_SIZE - offset;
--
2.9.3
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH V2 linux-next] staging: media: atomisp: kmap() can't fail
2017-04-26 18:44 [PATCH V2 linux-next] staging: media: atomisp: kmap() can't fail Fabian Frederick
@ 2017-04-26 23:02 ` Alan Cox
0 siblings, 0 replies; 2+ messages in thread
From: Alan Cox @ 2017-04-26 23:02 UTC (permalink / raw)
To: Fabian Frederick, Mauro Carvalho Chehab, Greg Kroah-Hartman
Cc: Jan Kara, linux-kernel
On Wed, 2017-04-26 at 20:44 +0200, Fabian Frederick wrote:
> There's no need to check kmap() return value because it won't fail.
> If it's highmem mapping, it will receive virtual address
> or a new one; if it's lowmem, all kernel pages are already being
> mapped.
>
> (Thanks to Jan Kara for explanations)
>
Thanks - queued.
Alan
^ permalink raw reply [flat|nested] 2+ messages in thread
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2017-04-26 18:44 [PATCH V2 linux-next] staging: media: atomisp: kmap() can't fail Fabian Frederick
2017-04-26 23:02 ` Alan Cox
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