[alsa-devel] [PATCH 2/2] misc: sram: switch to ioremap_wc from ioremap

[Abhilash Kesavan]

Hi Rob and Philipp,

On Tue, Jan 6, 2015 at 10:57 PM, Rob Herring <robherring2 at gmail.com> wrote:
> On Tue, Jan 6, 2015 at 10:54 AM, Philipp Zabel <p.zabel at pengutronix.de> wrote:
>> Hi Abhilash,
>>
>> Am Dienstag, den 06.01.2015, 19:57 +0530 schrieb Abhilash Kesavan:
>>> >> From the existing dts files, omap, imx, rockchip and exynos seem to be
>>> >> the only users of the sram allocator code. I have tested this on
>>> >> Exynos5420, Exynos5800 and Exynos7; there is no change in behavior
>>> >> seen on these boards. Tested-by for other SoCs would be appreciated.
>>> >
>>> > Sorry for the delay, these seems to boot OK on omap4, so from that
>>> > point of view:
>>> >
>>> > Tested-by: Tony Lindgren <tony at atomide.com>
>>>
>>> Thanks a lot for testing this. If someone with imx and rockchip boards
>>> could help test this out, then we could look to get this in.
>>
>> This shouldn't be a problem on i.MX, the coda driver doesn't access SRAM
>> from the CPU at all.
>
> Audio buffers are typically (perhaps not in mainline) in SRAM on i.MX
> chips which are accessed by CPU and probably mmap'ed to userspace.
> That could cause a mismatch in mappings although I would not expect
> both the kernel and user space to touch the buffer. That being said, I
> don't think this change should cause problems for i.MX (from what I
> can remember).

Thanks for the confirmation regarding the i.MX chips. That leaves
rockchip, can someone help with it please ?

Regards,
Abhilash
>
> Rob