2016-12-19 06:53:21

by Vivek Gautam

Subject: [PATCH] nvmem: core: Allow ignoring length when reading a cell

nvmem_cell_read() API fills in the argument 'len' with
the number of bytes read from the cell. Many users don't
care about this length value. So allow users to pass a
NULL pointer to this len field.

Signed-off-by: Vivek Gautam <[email protected]>
---

Based on torvalds's master branch.
- Tested against 'next-20161219' tag on db410c (apq8016) target
for thermal sensors.

drivers/nvmem/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 965911d..4c38842 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -970,7 +970,8 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem,
if (cell->bit_offset || cell->nbits)
nvmem_shift_read_buffer_in_place(cell, buf);

- *len = cell->bytes;
+ if (len)
+ *len = cell->bytes;

return 0;
}
@@ -979,7 +980,8 @@ static int __nvmem_cell_read(struct nvmem_device *nvmem,
* nvmem_cell_read() - Read a given nvmem cell
*
* @cell: nvmem cell to be read.
- * @len: pointer to length of cell which will be populated on successful read.
+ * @len: pointer to length of cell which will be populated on successful read;
+ * can be NULL.
*
* Return: ERR_PTR() on error or a valid pointer to a char * buffer on success.
* The buffer should be freed by the consumer with a kfree().
--
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a Linux Foundation Collaborative Project

2016-12-19 21:47:10

by Stephen Boyd

Subject: Re: [PATCH] nvmem: core: Allow ignoring length when reading a cell

On 12/19, Vivek Gautam wrote:
> nvmem_cell_read() API fills in the argument 'len' with
> the number of bytes read from the cell. Many users don't
> care about this length value. So allow users to pass a
> NULL pointer to this len field.
>
> Signed-off-by: Vivek Gautam <[email protected]>
> ---

Reviewed-by: Stephen Boyd <[email protected]>

--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

2016-12-20 04:03:55

by Vivek Gautam

Subject: Re: [PATCH] nvmem: core: Allow ignoring length when reading a cell

On Tue, Dec 20, 2016 at 3:17 AM, Stephen Boyd <[email protected]> wrote:
> On 12/19, Vivek Gautam wrote:
>> nvmem_cell_read() API fills in the argument 'len' with
>> the number of bytes read from the cell. Many users don't
>> care about this length value. So allow users to pass a
>> NULL pointer to this len field.
>>
>> Signed-off-by: Vivek Gautam <[email protected]>
>> ---
>
> Reviewed-by: Stephen Boyd <[email protected]>

Thanks Stephen.


--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project