sun5i: bump DEBE priority (useful on a10s only)

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).

Signed-off-by Michal Suchanek <[email protected]>

---
  arch/arm/cpu/armv7/sunxi/dram_sun4i.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

arch/arm/cpu/armv7/sunxi/dram_sun4i.c +1 -1

index ec8aaa7..e20cd2b 100644
@@ -207,7 +207,7 @@ static u32 hpcr_value[32] = {
  	0, 0, 0, 0,
  	0, 0, 0, 0,
  	0, 0, 0, 0,
-	0x1031, 0x1031, 0x0735, 0x1035,
+	0x1031, 0x1031, 0x0735, 0x1037,
  	0x1035, 0x0731, 0x1031, 0,
  	0x0301, 0x0301, 0x0301, 0x0301,
  	0x0301, 0x0301, 0x0301, 0

Current value is 1.25V. Most boards use 1.3V which is expected more stable. Can be overriden later by kernel setting anyway.

Signed-off-by Michal Suchanek <[email protected]>

---
  board/sunxi/board.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

board/sunxi/board.c +1 -1

index 4c1c69a..dda2d43 100644
@@ -162,7 +162,7 @@ void sunxi_board_init(void)
  	power_failed = axp152_init();
  	power_failed |= axp152_set_dcdc2(1400);
  	power_failed |= axp152_set_dcdc3(1500);
-	power_failed |= axp152_set_dcdc4(1250);
+	power_failed |= axp152_set_dcdc4(1300);
  	power_failed |= axp152_set_ldo2(3000);
  #endif
  #ifdef CONFIG_AXP209_POWER

Hi,

Quoted 5 lines · Michal Suchanek

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 ?

Quoted 11 lines · On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 5 lines · Michal Suchanek

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.

Quoted 15 lines · Siarhei Siamashka

Quoted 11 lines · On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 5 lines · Michal Suchanek

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 ?

Quoted 8 lines

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.

Hi,

Quoted 26 lines · Michal Suchanek

Quoted 15 lines · Siarhei Siamashka

Quoted 11 lines · On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 5 lines · Michal Suchanek

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 ?

Quoted 8 lines

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.

Quoted 3 lines

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.

Hi,

Quoted 55 lines · Hans de Goede

Hi,

Quoted 33 lines · Michal Suchanek

Quoted 20 lines · Siarhei Siamashka

Quoted 7 lines · On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 4 lines · Michal Suchanek

Setting magic 'reserved' hpcr bit on sun5i DEBE seems required for smooth HDMI scanout of large frambuffer (eg. 1080p).

Quoted 7 lines

Quoted 3 lines

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 ?

Quoted 8 lines

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.

Quoted 3 lines

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.

Quoted 2 lines

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.

Also instead of changing the priority to 0x1037, can you try changing it to 0x5031, this is what sun4i uses after Siarhei's fixes, and perhaps it is the right value to use for DEFE everywhere in general.

Quoted 11 lines · On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 5 lines · Michal Suchanek

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.

I may try to check A20 with the bus width artificially reduced to 16 bits (not a totally unrealistic configuration, since A20-OLinuXino-LIME board exists). If sun5i and sun7i are similar enough, then the magic reserved bit may have some effect there too. But that's a different hardware either way.

Quoted 24 lines · On Mon, 19 Jan 2015 06:29:47 +0200 Siarhei Siamashka…

Quoted 11 lines · On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 5 lines · Michal Suchanek

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.

Quoted 5 lines

I may try to check A20 with the bus width artificially reduced to 16 bits (not a totally unrealistic configuration, since A20-OLinuXino-LIME board exists). If sun5i and sun7i are similar enough, then the magic reserved bit may have some effect there too. But that's a different hardware either way.

Done these tests with A20. Ironically, now the tables have turned and A10 seems to be doing a better job than A20 at low DRAM clock speeds (~408MHz) and 16-bit bus width when dealing with full-hd monitors.

Just like Michal observed on A10s, setting 0x5031 as DEFE host port config makes things much worse on A20. Overall, the test results look in the following way on A20 with 16-bit DRAM clocked at 408MHz (yes, none of the real boards uses such a slow DRAM setup) while running lima-memtester and driving 1920x1080-32 at 60Hz monitor:

0x1035 - The screen regularly blanks, but comes back again instantly. 0x1037 - The screen regularly blanks, but comes back again instantly. 0x5031 - Severe screen shaking.

Unlike A10, there does not seem to be any difference between using DEBE or DEFE for framebuffer scanout on A20, so using DEBE has the same effect as listed above. Setting the magic 'reserved' hpcr bit 1 (0x1037 value) does not seem to have any effect on sun7i. It is great that it is apparently helping on sun5i/A10s though.

Hi,

Quoted 47 lines · Siarhei Siamashka

Quoted 24 lines · On Mon, 19 Jan 2015 06:29:47 +0200 Siarhei Siamashka…

Quoted 11 lines · On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 5 lines · Michal Suchanek

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.

Quoted 5 lines

I may try to check A20 with the bus width artificially reduced to 16 bits (not a totally unrealistic configuration, since A20-OLinuXino-LIME board exists). If sun5i and sun7i are similar enough, then the magic reserved bit may have some effect there too. But that's a different hardware either way.

Done these tests with A20. Ironically, now the tables have turned and A10 seems to be doing a better job than A20 at low DRAM clock speeds (~408MHz) and 16-bit bus width when dealing with full-hd monitors.

Just like Michal observed on A10s, setting 0x5031 as DEFE host port config makes things much worse on A20. Overall, the test results look in the following way on A20 with 16-bit DRAM clocked at 408MHz (yes, none of the real boards uses such a slow DRAM setup) while running lima-memtester and driving 1920x1080-32 at 60Hz monitor:

0x1035 - The screen regularly blanks, but comes back again instantly. 0x1037 - The screen regularly blanks, but comes back again instantly. 0x5031 - Severe screen shaking.

Quoted 5 lines

Unlike A10, there does not seem to be any difference between using DEBE or DEFE for framebuffer scanout on A20, so using DEBE has the same effect as listed above. Setting the magic 'reserved' hpcr bit 1 (0x1037 value) does not seem to have any effect on sun7i. It is great that it is apparently helping on sun5i/A10s though.

Thanks for running these tests, this makes me more confident that I only need to enable DEFE in u-boot on A10, and can directly use DEBE on the others.

Quoted 56 lines · On Tue, 20 Jan 2015 14:16:35 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 52 lines · Siarhei Siamashka

Quoted 24 lines · On Mon, 19 Jan 2015 06:29:47 +0200 Siarhei Siamashka…

Quoted 11 lines · On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 5 lines · Michal Suchanek

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.

Quoted 5 lines

I may try to check A20 with the bus width artificially reduced to 16 bits (not a totally unrealistic configuration, since A20-OLinuXino-LIME board exists). If sun5i and sun7i are similar enough, then the magic reserved bit may have some effect there too. But that's a different hardware either way.

Done these tests with A20. Ironically, now the tables have turned and A10 seems to be doing a better job than A20 at low DRAM clock speeds (~408MHz) and 16-bit bus width when dealing with full-hd monitors.

Just like Michal observed on A10s, setting 0x5031 as DEFE host port config makes things much worse on A20. Overall, the test results look in the following way on A20 with 16-bit DRAM clocked at 408MHz (yes, none of the real boards uses such a slow DRAM setup) while running lima-memtester and driving 1920x1080-32 at 60Hz monitor:

0x1035 - The screen regularly blanks, but comes back again instantly. 0x1037 - The screen regularly blanks, but comes back again instantly. 0x5031 - Severe screen shaking.

Unlike A10, there does not seem to be any difference between using DEBE or DEFE for framebuffer scanout on A20, so using DEBE has the same effect as listed above. Setting the magic 'reserved' hpcr bit 1 (0x1037 value) does not seem to have any effect on sun7i. It is great that it is apparently helping on sun5i/A10s though.

Quoted 3 lines

Thanks for running these tests, this makes me more confident that I only need to enable DEFE in u-boot on A10, and can directly use DEBE on the others.

But what about A10s? Do we want to do something about it?

Regarding the 0x5031 settings. It just looks like sun7i (and sun5i?) might have an upper cap for the 'CmdNum' bits (bits 15-8) and bumping it to 0x50 or even 0xFF is not effective. If we instead reduce 'CmdNum' for the CPU and GPU host ports to 1, then the screen glitches disappear too.

Eventually I would like to also identify the source of occasional monitor blinks on sun7i with full-hd monitors and slow DRAM settings in order to apply some sort of a workaround.

Maybe it has something to
do with DRAM refresh settings, maybe it is something else. But for now it can be left alone because the problem is not easily reproducible on 'normal' workloads (it needs a special setup in which CPU & GPU are torturing slow DRAM simultaneously, trying to disrupt the 1920x1080-32 at 60Hz framebuffer scanout).

Hi,

Quoted 75 lines · Siarhei Siamashka

Quoted 69 lines · On Tue, 20 Jan 2015 14:16:35 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 56 lines · Siarhei Siamashka

Quoted 31 lines · On Mon, 19 Jan 2015 06:29:47 +0200 Siarhei Siamashka…

Quoted 14 lines · On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 9 lines · Michal Suchanek

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).

Quoted 3 lines

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.

Quoted 5 lines

I may try to check A20 with the bus width artificially reduced to 16 bits (not a totally unrealistic configuration, since A20-OLinuXino-LIME board exists). If sun5i and sun7i are similar enough, then the magic reserved bit may have some effect there too. But that's a different hardware either way.

Done these tests with A20. Ironically, now the tables have turned and A10 seems to be doing a better job than A20 at low DRAM clock speeds (~408MHz) and 16-bit bus width when dealing with full-hd monitors.

Just like Michal observed on A10s, setting 0x5031 as DEFE host port config makes things much worse on A20. Overall, the test results look in the following way on A20 with 16-bit DRAM clocked at 408MHz (yes, none of the real boards uses such a slow DRAM setup) while running lima-memtester and driving 1920x1080-32 at 60Hz monitor:

0x1035 - The screen regularly blanks, but comes back again instantly. 0x1037 - The screen regularly blanks, but comes back again instantly. 0x5031 - Severe screen shaking.

Quoted 5 lines

Unlike A10, there does not seem to be any difference between using DEBE or DEFE for framebuffer scanout on A20, so using DEBE has the same effect as listed above. Setting the magic 'reserved' hpcr bit 1 (0x1037 value) does not seem to have any effect on sun7i. It is great that it is apparently helping on sun5i/A10s though.

Thanks for running these tests, this makes me more confident that I only need to enable DEFE in u-boot on A10, and can directly use DEBE on the others.

Quoted 1 line

But what about A10s? Do we want to do something about it?

Once we have some feedback from hramrach from running tests with / without the frontend enabled, then yes, unless the fix is to simple disable the frontend, and then u-boot probably is fine as is.

Hello,

Quoted 79 lines · Hans de Goede

Hi,

Quoted 75 lines · Siarhei Siamashka

Quoted 69 lines · On Tue, 20 Jan 2015 14:16:35 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 56 lines · Siarhei Siamashka

Quoted 31 lines · On Mon, 19 Jan 2015 06:29:47 +0200 Siarhei Siamashka…

Quoted 14 lines · On Sun, 04 Jan 2015 20:49:38 +0100 Hans de Goede <[email protected]> wrote:

Hi,

Quoted 9 lines · Michal Suchanek

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).

Quoted 3 lines

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.

Quoted 5 lines

I may try to check A20 with the bus width artificially reduced to 16 bits (not a totally unrealistic configuration, since A20-OLinuXino-LIME board exists). If sun5i and sun7i are similar enough, then the magic reserved bit may have some effect there too. But that's a different hardware either way.

Done these tests with A20. Ironically, now the tables have turned and A10 seems to be doing a better job than A20 at low DRAM clock speeds (~408MHz) and 16-bit bus width when dealing with full-hd monitors.

Just like Michal observed on A10s, setting 0x5031 as DEFE host port config makes things much worse on A20. Overall, the test results look in the following way on A20 with 16-bit DRAM clocked at 408MHz (yes, none of the real boards uses such a slow DRAM setup) while running lima-memtester and driving 1920x1080-32 at 60Hz monitor:

0x1035 - The screen regularly blanks, but comes back again instantly. 0x1037 - The screen regularly blanks, but comes back again instantly. 0x5031 - Severe screen shaking.

Quoted 5 lines

Unlike A10, there does not seem to be any difference between using DEBE or DEFE for framebuffer scanout on A20, so using DEBE has the same effect as listed above. Setting the magic 'reserved' hpcr bit 1 (0x1037 value) does not seem to have any effect on sun7i. It is great that it is apparently helping on sun5i/A10s though.

Thanks for running these tests, this makes me more confident that I only need to enable DEFE in u-boot on A10, and can directly use DEBE on the others.

Quoted 6 lines

Quoted 1 line

But what about A10s? Do we want to do something about it?

Once we have some feedback from hramrach from running tests with / without the frontend enabled, then yes, unless the fix is to simple disable the frontend, and then u-boot probably is fine as is.

I need to re-test this but it seemed that on my a10s board enabling and disabling scaler had pretty much no impact on display performance. Increasing the priority of the display ports did not seem to increase display performance either. However, setting the 'magic' bit degraded memory throughput as reported by the lima-memspeed somewhat but enabled jump-free lima-memtester rotating cube. Since a13 has no hdmi this is moot for most sun5i hardware.

Affected would be the obsolete olinuxinos and a few HDMI sticks that actually had a10s in them.