[PATCH v6 1/3] spi/pl022: Add chip select handling via GPIO
shiraz hashim
shiraz.linux.kernel at gmail.com
Sun Sep 2 23:12:49 EST 2012
Hi Linus,
On Sun, Sep 2, 2012 at 12:48 PM, Linus Walleij <linus.walleij at linaro.org> wrote:
> On Sat, Sep 1, 2012 at 1:14 PM, shiraz hashim
> <shiraz.linux.kernel at gmail.com> wrote:
>> Hi Roland,
>>
>> On Wed, Aug 22, 2012 at 7:19 PM, Roland Stigge <stigge at antcom.de> wrote:
>>> @@ -2016,6 +2030,8 @@ pl022_probe(struct amba_device *adev, co
>>> pl022->master_info = platform_info;
>>> pl022->adev = adev;
>>> pl022->vendor = id->data;
>>> + /* Point chipselects to allocated memory beyond the main struct */
>>> + pl022->chipselects = (int *) pl022 + sizeof(struct pl022);
>>
>> This is going beyond memory allocated for chipselects
>> as it adds 4 * sizeof(struct pl022) bytes to pl022.
>
> Yes that is why the allocation looks like this:
>
> + master = spi_alloc_master(dev, sizeof(struct pl022) + sizeof(int) *
> + platform_info->num_chipselect);
>
The allocation is such because type of chipselects is int.
The statement for allocation is correct, but
pl022->chipselects = (int *) pl022 + sizeof(struct pl022);
is not adding sizeof(struct pl022) bytes to pl022 base (which we want),
but infact 4 times the size of pl022 (because type of pl022 is now int *).
Do you get my point ? This would go way beyond memory allocated
for chipselects.
--
regards
Shiraz Hashim
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