[U-Boot] [PATCH v2 02/12] x86: Add an accelerated memmove() function

[Bin Meng]

On Sat, Oct 8, 2016 at 1:53 PM, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Simon,
>
> On Sat, Oct 8, 2016 at 10:25 AM, Bin Meng <bmeng.cn at gmail.com> wrote:
>> Hi Simon,
>>
>> On Thu, Oct 6, 2016 at 10:42 AM, Simon Glass <sjg at chromium.org> wrote:
>>> Bring in a faster memmove() from Linux 4.7. This speeds up scrolling on the
>>> display.
>>>
>>> Signed-off-by: Simon Glass <sjg at chromium.org>
>>> ---
>>>
>>> Changes in v2:
>>> - Move the code into string.c
>>> - Fix multi-line comments that should not be
>>>
>>>  arch/x86/include/asm/string.h |   2 +-
>>>  arch/x86/lib/string.c         | 161 ++++++++++++++++++++++++++++++++++++++++++
>>>  2 files changed, 162 insertions(+), 1 deletion(-)
>>>
>>
>> Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
>>
>> Tested on Crown Bay with an external PCIe graphics card
>> Tested-by: Bin Meng <bmeng.cn at gmail.com>
>>
>> However, I did not see significant speed up on screen scrolling...
>>
>
> Crown Bay is still using cfb_console.c, which is the legacy driver
> that does not use memmove(). Looks the new console_xxx driver is using
> memmove(). I guess I will need convert Crown Bay to use DM video.
>

Testing shows that on Crown Bay, the DM driver with the optimized
memmove() does not improve the performance compared to legacy
cfb_console driver. But on Bayleybay, memmove() indeed helps the
screen scrolling.

Regards,
Bin