* [PATCH 0/2] ARM: dts: sunxi: Fix cpufreq instabilities
@ 2015-03-19 2:39 Chen-Yu Tsai
2015-03-19 2:39 ` [PATCH 1/2] ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting Chen-Yu Tsai
2015-03-19 2:39 ` [PATCH 2/2] ARM: dts: sunxi: Remove overclocked/overvoltaged OPP Chen-Yu Tsai
0 siblings, 2 replies; 11+ messages in thread
From: Chen-Yu Tsai @ 2015-03-19 2:39 UTC (permalink / raw)
To: linux-arm-kernel
Hi Maxime,
Here are 2 dts fixes for sunxi cpufreq support, aimed at 4.0.
The first patch limits the Olimex A10-Lime to 960MHz, as a few people
reported on IRC that it was unstable at 1008MHz.
The second patch removes the overclocking settings from sun5i/sun7i
dts, so all the boards will be stable, regardless of whether regulators
were added or not.
I would like to revisit this after the new OPP bindings are merged
and support added to cpufreq-dt.
Regards
ChenYu
Chen-Yu Tsai (2):
ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
ARM: dts: sunxi: Remove overclocked/overvoltaged OPP
arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts | 14 ++++++++++++++
arch/arm/boot/dts/sun5i-a13.dtsi | 3 +--
arch/arm/boot/dts/sun7i-a20.dtsi | 3 +--
3 files changed, 16 insertions(+), 4 deletions(-)
--
2.1.4
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 1/2] ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
2015-03-19 2:39 [PATCH 0/2] ARM: dts: sunxi: Fix cpufreq instabilities Chen-Yu Tsai
@ 2015-03-19 2:39 ` Chen-Yu Tsai
2015-03-19 6:57 ` Siarhei Siamashka
2015-03-19 2:39 ` [PATCH 2/2] ARM: dts: sunxi: Remove overclocked/overvoltaged OPP Chen-Yu Tsai
1 sibling, 1 reply; 11+ messages in thread
From: Chen-Yu Tsai @ 2015-03-19 2:39 UTC (permalink / raw)
To: linux-arm-kernel
The Olimex A10-Lime is known to be unstable when running at 1008MHz.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts b/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
index 31dc2f1c3870..16ecb8938e19 100644
--- a/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
+++ b/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
@@ -74,6 +74,20 @@
status = "okay";
};
+&cpu0 {
+ /* The A10-Lime is known to be unstable when running at 1008 MHz */
+ operating-points = <
+ /* kHz uV */
+ 960000 1400000
+ 912000 1400000
+ 864000 1300000
+ 720000 1200000
+ 528000 1100000
+ 312000 1000000
+ 144000 900000
+ >;
+};
+
&ehci0 {
status = "okay";
};
--
2.1.4
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 2/2] ARM: dts: sunxi: Remove overclocked/overvoltaged OPP
2015-03-19 2:39 [PATCH 0/2] ARM: dts: sunxi: Fix cpufreq instabilities Chen-Yu Tsai
2015-03-19 2:39 ` [PATCH 1/2] ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting Chen-Yu Tsai
@ 2015-03-19 2:39 ` Chen-Yu Tsai
2015-03-19 6:59 ` Siarhei Siamashka
1 sibling, 1 reply; 11+ messages in thread
From: Chen-Yu Tsai @ 2015-03-19 2:39 UTC (permalink / raw)
To: linux-arm-kernel
Without proper regulator support for individual boards, it is dangerous
to have overclocked/overvoltaged OPPs in the list. Cpufreq will increase
the frequency without the accompanying voltage increase, resulting in
an unstable system.
Remove them for now. We can revisit them with the new version of OPP
bindings, which support boost settings and frequency ranges, among
other things.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
---
arch/arm/boot/dts/sun5i-a13.dtsi | 3 +--
arch/arm/boot/dts/sun7i-a20.dtsi | 3 +--
2 files changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/arm/boot/dts/sun5i-a13.dtsi b/arch/arm/boot/dts/sun5i-a13.dtsi
index 5d9ce84486bb..39264f7c7ae6 100644
--- a/arch/arm/boot/dts/sun5i-a13.dtsi
+++ b/arch/arm/boot/dts/sun5i-a13.dtsi
@@ -140,7 +140,6 @@
clock-latency = <244144>; /* 8 32k periods */
operating-points = <
/* kHz uV */
- 1104000 1500000
1008000 1400000
912000 1350000
864000 1300000
@@ -150,7 +149,7 @@
>;
#cooling-cells = <2>;
cooling-min-level = <0>;
- cooling-max-level = <6>;
+ cooling-max-level = <5>;
};
&ehci0 {
diff --git a/arch/arm/boot/dts/sun7i-a20.dtsi b/arch/arm/boot/dts/sun7i-a20.dtsi
index 3a8530b79f1c..fdd181792b4b 100644
--- a/arch/arm/boot/dts/sun7i-a20.dtsi
+++ b/arch/arm/boot/dts/sun7i-a20.dtsi
@@ -105,7 +105,6 @@
clock-latency = <244144>; /* 8 32k periods */
operating-points = <
/* kHz uV */
- 1008000 1450000
960000 1400000
912000 1400000
864000 1300000
@@ -116,7 +115,7 @@
>;
#cooling-cells = <2>;
cooling-min-level = <0>;
- cooling-max-level = <7>;
+ cooling-max-level = <6>;
};
cpu at 1 {
--
2.1.4
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 1/2] ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
2015-03-19 2:39 ` [PATCH 1/2] ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting Chen-Yu Tsai
@ 2015-03-19 6:57 ` Siarhei Siamashka
2015-03-19 8:17 ` Chen-Yu Tsai
2015-03-26 16:58 ` [linux-sunxi] " Iain Paton
0 siblings, 2 replies; 11+ messages in thread
From: Siarhei Siamashka @ 2015-03-19 6:57 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, 19 Mar 2015 10:39:32 +0800
Chen-Yu Tsai <wens@csie.org> wrote:
> The Olimex A10-Lime is known to be unstable when running at 1008MHz.
>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
> arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts b/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
> index 31dc2f1c3870..16ecb8938e19 100644
> --- a/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
> +++ b/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
> @@ -74,6 +74,20 @@
> status = "okay";
> };
>
> +&cpu0 {
> + /* The A10-Lime is known to be unstable when running at 1008 MHz */
> + operating-points = <
> + /* kHz uV */
> + 960000 1400000
> + 912000 1400000
> + 864000 1300000
> + 720000 1200000
> + 528000 1100000
> + 312000 1000000
> + 144000 900000
> + >;
> +};
> +
> &ehci0 {
> status = "okay";
> };
Thanks for the patch. At least it should make my A10-OLinuXino-LIME
working without obvious failures out of the box (the U-Boot is still
another story though and there is a gap during boot up when the board
is running with unreliable settings, but the probability of a failure
is rather low).
I should also mention that using 960MHz @1.4V does not fail, but it does
not have any safety headroom either (the cyan 'sun4i_poorlime' line
on the plot):
http://people.freedesktop.org/~siamashka/files/20140512/sunxi-cpufreq-plot.png
On the other hand, my board is on the worst part of the spectrum (many
other a10-lime boards do not fail even at 1008MHz), so maybe having
extra safety headroom is less necessary.
An interesting question is whether the same problem may be reproducible
on the Allwinner A10 devices other than A10-OLinuXino-LIME. My original
problem report
https://www.mail-archive.com/linux-sunxi at googlegroups.com/msg04343.html
mentioned the A10-OLinuXino-LIME rev.A and introduced some sort of
a bias by itself. At least I have seen people saying something like
"my a10-lime revision is not rev.A, so it's none of my concern and
I'm not going to bother running any tests". So far we have accumulated
reports from 4 or 5 people having this reliability problem on their
A10-OLinuXino-LIME (various revisions, not just rev.A), but not
much from the other boards owners.
Anyway, this particular patch is
Tested-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Acked-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
--
Best regards,
Siarhei Siamashka
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 2/2] ARM: dts: sunxi: Remove overclocked/overvoltaged OPP
2015-03-19 2:39 ` [PATCH 2/2] ARM: dts: sunxi: Remove overclocked/overvoltaged OPP Chen-Yu Tsai
@ 2015-03-19 6:59 ` Siarhei Siamashka
2015-03-19 7:11 ` Chen-Yu Tsai
0 siblings, 1 reply; 11+ messages in thread
From: Siarhei Siamashka @ 2015-03-19 6:59 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, 19 Mar 2015 10:39:33 +0800
Chen-Yu Tsai <wens@csie.org> wrote:
> Without proper regulator support for individual boards, it is dangerous
> to have overclocked/overvoltaged OPPs in the list. Cpufreq will increase
> the frequency without the accompanying voltage increase, resulting in
> an unstable system.
>
> Remove them for now. We can revisit them with the new version of OPP
> bindings, which support boost settings and frequency ranges, among
> other things.
>
> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> ---
> arch/arm/boot/dts/sun5i-a13.dtsi | 3 +--
> arch/arm/boot/dts/sun7i-a20.dtsi | 3 +--
> 2 files changed, 2 insertions(+), 4 deletions(-)
What about the sun4i-a10.dtsi file? Was it forgotten or skipped
deliberately?
--
Best regards,
Siarhei Siamashka
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 2/2] ARM: dts: sunxi: Remove overclocked/overvoltaged OPP
2015-03-19 6:59 ` Siarhei Siamashka
@ 2015-03-19 7:11 ` Chen-Yu Tsai
2015-03-19 8:14 ` Chen-Yu Tsai
0 siblings, 1 reply; 11+ messages in thread
From: Chen-Yu Tsai @ 2015-03-19 7:11 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Mar 19, 2015 at 2:59 PM, Siarhei Siamashka
<siarhei.siamashka@gmail.com> wrote:
> On Thu, 19 Mar 2015 10:39:33 +0800
> Chen-Yu Tsai <wens@csie.org> wrote:
>
>> Without proper regulator support for individual boards, it is dangerous
>> to have overclocked/overvoltaged OPPs in the list. Cpufreq will increase
>> the frequency without the accompanying voltage increase, resulting in
>> an unstable system.
>>
>> Remove them for now. We can revisit them with the new version of OPP
>> bindings, which support boost settings and frequency ranges, among
>> other things.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> ---
>> arch/arm/boot/dts/sun5i-a13.dtsi | 3 +--
>> arch/arm/boot/dts/sun7i-a20.dtsi | 3 +--
>> 2 files changed, 2 insertions(+), 4 deletions(-)
>
> What about the sun4i-a10.dtsi file? Was it forgotten or skipped
> deliberately?
sun4i-a10.dtsi does not have any overclocked/overvoltaged settings.
The highest setting is 1008MHz @ 1.4V.
ChenYu
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 2/2] ARM: dts: sunxi: Remove overclocked/overvoltaged OPP
2015-03-19 7:11 ` Chen-Yu Tsai
@ 2015-03-19 8:14 ` Chen-Yu Tsai
0 siblings, 0 replies; 11+ messages in thread
From: Chen-Yu Tsai @ 2015-03-19 8:14 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Mar 19, 2015 at 3:11 PM, Chen-Yu Tsai <wens@csie.org> wrote:
> On Thu, Mar 19, 2015 at 2:59 PM, Siarhei Siamashka
> <siarhei.siamashka@gmail.com> wrote:
>> On Thu, 19 Mar 2015 10:39:33 +0800
>> Chen-Yu Tsai <wens@csie.org> wrote:
>>
>>> Without proper regulator support for individual boards, it is dangerous
>>> to have overclocked/overvoltaged OPPs in the list. Cpufreq will increase
>>> the frequency without the accompanying voltage increase, resulting in
>>> an unstable system.
>>>
>>> Remove them for now. We can revisit them with the new version of OPP
>>> bindings, which support boost settings and frequency ranges, among
>>> other things.
>>>
>>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>>> ---
>>> arch/arm/boot/dts/sun5i-a13.dtsi | 3 +--
>>> arch/arm/boot/dts/sun7i-a20.dtsi | 3 +--
>>> 2 files changed, 2 insertions(+), 4 deletions(-)
>>
>> What about the sun4i-a10.dtsi file? Was it forgotten or skipped
>> deliberately?
>
> sun4i-a10.dtsi does not have any overclocked/overvoltaged settings.
> The highest setting is 1008MHz @ 1.4V.
Oops. Sorry. I missed it. Will send v2.
ChenYu
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 1/2] ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
2015-03-19 6:57 ` Siarhei Siamashka
@ 2015-03-19 8:17 ` Chen-Yu Tsai
2015-03-19 10:28 ` Siarhei Siamashka
2015-03-26 16:58 ` [linux-sunxi] " Iain Paton
1 sibling, 1 reply; 11+ messages in thread
From: Chen-Yu Tsai @ 2015-03-19 8:17 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Mar 19, 2015 at 2:57 PM, Siarhei Siamashka
<siarhei.siamashka@gmail.com> wrote:
> On Thu, 19 Mar 2015 10:39:32 +0800
> Chen-Yu Tsai <wens@csie.org> wrote:
>
>> The Olimex A10-Lime is known to be unstable when running at 1008MHz.
>>
>> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
>> ---
>> arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts | 14 ++++++++++++++
>> 1 file changed, 14 insertions(+)
>>
>> diff --git a/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts b/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
>> index 31dc2f1c3870..16ecb8938e19 100644
>> --- a/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
>> +++ b/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
>> @@ -74,6 +74,20 @@
>> status = "okay";
>> };
>>
>> +&cpu0 {
>> + /* The A10-Lime is known to be unstable when running at 1008 MHz */
>> + operating-points = <
>> + /* kHz uV */
>> + 960000 1400000
>> + 912000 1400000
>> + 864000 1300000
>> + 720000 1200000
>> + 528000 1100000
>> + 312000 1000000
>> + 144000 900000
>> + >;
>> +};
>> +
>> &ehci0 {
>> status = "okay";
>> };
>
> Thanks for the patch. At least it should make my A10-OLinuXino-LIME
> working without obvious failures out of the box (the U-Boot is still
> another story though and there is a gap during boot up when the board
> is running with unreliable settings, but the probability of a failure
> is rather low).
>
> I should also mention that using 960MHz @1.4V does not fail, but it does
> not have any safety headroom either (the cyan 'sun4i_poorlime' line
> on the plot):
>
> http://people.freedesktop.org/~siamashka/files/20140512/sunxi-cpufreq-plot.png
>
> On the other hand, my board is on the worst part of the spectrum (many
> other a10-lime boards do not fail even at 1008MHz), so maybe having
> extra safety headroom is less necessary.
>
> An interesting question is whether the same problem may be reproducible
> on the Allwinner A10 devices other than A10-OLinuXino-LIME. My original
> problem report
>
> https://www.mail-archive.com/linux-sunxi at googlegroups.com/msg04343.html
>
> mentioned the A10-OLinuXino-LIME rev.A and introduced some sort of
> a bias by itself. At least I have seen people saying something like
> "my a10-lime revision is not rev.A, so it's none of my concern and
> I'm not going to bother running any tests". So far we have accumulated
> reports from 4 or 5 people having this reliability problem on their
> A10-OLinuXino-LIME (various revisions, not just rev.A), but not
> much from the other boards owners.
>
> Anyway, this particular patch is
> Tested-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
> Acked-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
Good to hear it works. Did you test all the settings? I copied the
wrong settings, from sun5i-a13.dtsi instead of sun4i-a10.dtsi.
I'll send a fixed version later.
ChenYu
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 1/2] ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
2015-03-19 8:17 ` Chen-Yu Tsai
@ 2015-03-19 10:28 ` Siarhei Siamashka
0 siblings, 0 replies; 11+ messages in thread
From: Siarhei Siamashka @ 2015-03-19 10:28 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, 19 Mar 2015 16:17:30 +0800
Chen-Yu Tsai <wens@csie.org> wrote:
> On Thu, Mar 19, 2015 at 2:57 PM, Siarhei Siamashka
> <siarhei.siamashka@gmail.com> wrote:
> > On Thu, 19 Mar 2015 10:39:32 +0800
> > Chen-Yu Tsai <wens@csie.org> wrote:
> >
> >> The Olimex A10-Lime is known to be unstable when running at 1008MHz.
> >>
> >> Signed-off-by: Chen-Yu Tsai <wens@csie.org>
> >> ---
> >> arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts | 14 ++++++++++++++
> >> 1 file changed, 14 insertions(+)
> >>
> >> diff --git a/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts b/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
> >> index 31dc2f1c3870..16ecb8938e19 100644
> >> --- a/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
> >> +++ b/arch/arm/boot/dts/sun4i-a10-olinuxino-lime.dts
> >> @@ -74,6 +74,20 @@
> >> status = "okay";
> >> };
> >>
> >> +&cpu0 {
> >> + /* The A10-Lime is known to be unstable when running at 1008 MHz */
> >> + operating-points = <
> >> + /* kHz uV */
> >> + 960000 1400000
> >> + 912000 1400000
> >> + 864000 1300000
> >> + 720000 1200000
> >> + 528000 1100000
> >> + 312000 1000000
> >> + 144000 900000
> >> + >;
> >> +};
> >> +
> >> &ehci0 {
> >> status = "okay";
> >> };
> >
> > Thanks for the patch. At least it should make my A10-OLinuXino-LIME
> > working without obvious failures out of the box (the U-Boot is still
> > another story though and there is a gap during boot up when the board
> > is running with unreliable settings, but the probability of a failure
> > is rather low).
> >
> > I should also mention that using 960MHz @1.4V does not fail, but it does
> > not have any safety headroom either (the cyan 'sun4i_poorlime' line
> > on the plot):
> >
> > http://people.freedesktop.org/~siamashka/files/20140512/sunxi-cpufreq-plot.png
> >
> > On the other hand, my board is on the worst part of the spectrum (many
> > other a10-lime boards do not fail even at 1008MHz), so maybe having
> > extra safety headroom is less necessary.
> >
> > An interesting question is whether the same problem may be reproducible
> > on the Allwinner A10 devices other than A10-OLinuXino-LIME. My original
> > problem report
> >
> > https://www.mail-archive.com/linux-sunxi at googlegroups.com/msg04343.html
> >
> > mentioned the A10-OLinuXino-LIME rev.A and introduced some sort of
> > a bias by itself. At least I have seen people saying something like
> > "my a10-lime revision is not rev.A, so it's none of my concern and
> > I'm not going to bother running any tests". So far we have accumulated
> > reports from 4 or 5 people having this reliability problem on their
> > A10-OLinuXino-LIME (various revisions, not just rev.A), but not
> > much from the other boards owners.
> >
> > Anyway, this particular patch is
> > Tested-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
> > Acked-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>
>
> Good to hear it works. Did you test all the settings?
You have nailed it. I was about to send the results of the full
round of tests after running them a bit longer and revoke the
initial Tested-by.
Turns out that the 312MHz and 144MHz operating points fail to work
reliable and tend to deadlock:
Testing CPU 0
960 MHz ............................................................ OK
912 MHz ............................................................ OK
864 MHz ............................................................ OK
720 MHz ............................................................ OK
528 MHz ............................................................ OK
312 MHz ............................................................ OK
144 MHz Write failed: Broken pipe
Testing CPU 0
960 MHz ............................................................ OK
912 MHz ............................................................ OK
864 MHz ............................................................ OK
720 MHz ............................................................ OK
528 MHz ............................................................ OK
312 MHz .................Write failed: Broken pipe
> I copied the wrong settings, from sun5i-a13.dtsi instead of sun4i-a10.dtsi.
I guess, this explains the problems at lower operating points.
> I'll send a fixed version later.
Thanks.
--
Best regards,
Siarhei Siamashka
^ permalink raw reply [flat|nested] 11+ messages in thread
* [linux-sunxi] Re: [PATCH 1/2] ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
2015-03-19 6:57 ` Siarhei Siamashka
2015-03-19 8:17 ` Chen-Yu Tsai
@ 2015-03-26 16:58 ` Iain Paton
2015-03-26 17:56 ` Chen-Yu Tsai
1 sibling, 1 reply; 11+ messages in thread
From: Iain Paton @ 2015-03-26 16:58 UTC (permalink / raw)
To: linux-arm-kernel
On 19/03/15 06:57, Siarhei Siamashka wrote:
> I should also mention that using 960MHz @1.4V does not fail, but it does
> not have any safety headroom either (the cyan 'sun4i_poorlime' line
> on the plot):
>
> http://people.freedesktop.org/~siamashka/files/20140512/sunxi-cpufreq-plot.png
>
> On the other hand, my board is on the worst part of the spectrum (many
> other a10-lime boards do not fail even at 1008MHz), so maybe having
> extra safety headroom is less necessary.
>
> An interesting question is whether the same problem may be reproducible
> on the Allwinner A10 devices other than A10-OLinuXino-LIME. My original
> problem report
>
> https://www.mail-archive.com/linux-sunxi at googlegroups.com/msg04343.html
>
> mentioned the A10-OLinuXino-LIME rev.A and introduced some sort of
> a bias by itself. At least I have seen people saying something like
> "my a10-lime revision is not rev.A, so it's none of my concern and
> I'm not going to bother running any tests". So far we have accumulated
> reports from 4 or 5 people having this reliability problem on their
> A10-OLinuXino-LIME (various revisions, not just rev.A), but not
> much from the other boards owners.
I'm somewhat sad to see 1008MHz go. I have 2x revA A10-Lime boards that
are stable at 1008MHz with Maximes sunxi/for-next, a full regulator
description in the dts and a very recent u-boot. They are not stable at
1056 or above however.
Can I ask what the basis is for the 960MHz setting? I don't see any
instances of it in any of the a10 fex files, meaning it's likely not
very well tested.
If there's interest, I'll send the patch adding regulators to the dts for
the a10-lime.
Rgds,
Iain
^ permalink raw reply [flat|nested] 11+ messages in thread
* [linux-sunxi] Re: [PATCH 1/2] ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting
2015-03-26 16:58 ` [linux-sunxi] " Iain Paton
@ 2015-03-26 17:56 ` Chen-Yu Tsai
0 siblings, 0 replies; 11+ messages in thread
From: Chen-Yu Tsai @ 2015-03-26 17:56 UTC (permalink / raw)
To: linux-arm-kernel
Hi,
On Thu, Mar 26, 2015 at 9:58 AM, Iain Paton <ipaton0@gmail.com> wrote:
> On 19/03/15 06:57, Siarhei Siamashka wrote:
>
>> I should also mention that using 960MHz @1.4V does not fail, but it does
>> not have any safety headroom either (the cyan 'sun4i_poorlime' line
>> on the plot):
>>
>> http://people.freedesktop.org/~siamashka/files/20140512/sunxi-cpufreq-plot.png
>>
>> On the other hand, my board is on the worst part of the spectrum (many
>> other a10-lime boards do not fail even at 1008MHz), so maybe having
>> extra safety headroom is less necessary.
>>
>> An interesting question is whether the same problem may be reproducible
>> on the Allwinner A10 devices other than A10-OLinuXino-LIME. My original
>> problem report
>>
>> https://www.mail-archive.com/linux-sunxi at googlegroups.com/msg04343.html
>>
>> mentioned the A10-OLinuXino-LIME rev.A and introduced some sort of
>> a bias by itself. At least I have seen people saying something like
>> "my a10-lime revision is not rev.A, so it's none of my concern and
>> I'm not going to bother running any tests". So far we have accumulated
>> reports from 4 or 5 people having this reliability problem on their
>> A10-OLinuXino-LIME (various revisions, not just rev.A), but not
>> much from the other boards owners.
>
> I'm somewhat sad to see 1008MHz go. I have 2x revA A10-Lime boards that
> are stable at 1008MHz with Maximes sunxi/for-next, a full regulator
> description in the dts and a very recent u-boot. They are not stable at
> 1056 or above however.
>
>
> Can I ask what the basis is for the 960MHz setting? I don't see any
> instances of it in any of the a10 fex files, meaning it's likely not
> very well tested.
It was copied from the wrong file. Please see v2 of the series.
> If there's interest, I'll send the patch adding regulators to the dts for
> the a10-lime.
Please do.
ChenYu
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2015-03-26 17:56 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-03-19 2:39 [PATCH 0/2] ARM: dts: sunxi: Fix cpufreq instabilities Chen-Yu Tsai
2015-03-19 2:39 ` [PATCH 1/2] ARM: dts: sun4i: a10-lime: Override and remove 1008MHz OPP setting Chen-Yu Tsai
2015-03-19 6:57 ` Siarhei Siamashka
2015-03-19 8:17 ` Chen-Yu Tsai
2015-03-19 10:28 ` Siarhei Siamashka
2015-03-26 16:58 ` [linux-sunxi] " Iain Paton
2015-03-26 17:56 ` Chen-Yu Tsai
2015-03-19 2:39 ` [PATCH 2/2] ARM: dts: sunxi: Remove overclocked/overvoltaged OPP Chen-Yu Tsai
2015-03-19 6:59 ` Siarhei Siamashka
2015-03-19 7:11 ` Chen-Yu Tsai
2015-03-19 8:14 ` Chen-Yu Tsai
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).