[U-Boot] [linux-sunxi] [u-boot 2/2] sun5i: bump DEBE priority (useful on a10s only)

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 19-01-15 10:06, Michal Suchanek wrote:
> On 19 January 2015 at 05:29, Siarhei Siamashka
> <siarhei.siamashka@gmail.com> wrote:
>> On Sun, 04 Jan 2015 20:49:38 +0100
>> Hans de Goede <hdegoede@redhat.com> wrote:
>>
>>> Hi,
>>>
>>> On 04-01-15 20:19, Michal Suchanek wrote:
>>>>     Setting magic 'reserved' hpcr bit on sun5i DEBE seems required for
>>>>     smooth HDMI scanout of large frambuffer (eg. 1080p).
>>>>
>>>>     This fix comes at the cost of some overall memory bandwidth so it
>>>>     might be appropriate to detect a10s and only apply there (and not a13).
>>>
>>> Hmm, Sairhei is the expert on this, adding him to the Cc. Sairhei, what
>>> do you think of the proposed change ?
>>
>> I don't have A10s hardware, so have no idea and can't test anything
>> myself.
>>
>> It would be great to have a better description of what exactly is
>> happening before the patch. And precisely how the patch is helping.
>> A description of the test setup and benchmark numbers would be
>> appreciated. And it would be perfect if somebody else could reproduce
>> the test and confirm the results.
>
> The result is that with full HD HDMI output lima-memtester cube jumps
> without the patch and does not jump with the patch. I have only 1 A10s
> board.

Since you're running lima-memtester, I assume you're using a sunxi-3.4
kernel, correct?

Looking at the patch you're not modifying DEBE DRAM priority, but rather
DEFE priority.

Can you check the fex file and see what fb0_scaler_mode_enable is set too ?

If it is not enabled, it is weird that this fix helps, if it is enabled,
then this fix shouldn't be necessary, but maybe things are different on
sun5i vs sun4i.

Regardless can you try with fb0_scaler_mode_enable inverted from what it
is now, it would be good to know if it has any impact on sun5i.

Regards,

Hans