| Message ID | 20220210100638.19130-3-christianshewitt@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: dts: meson: remove CPU opps below 1GHz for G12B/SM1 | expand |
On 2022-02-10 10:06, Christian Hewitt wrote: > Amlogic SM1 devices experience CPU stalls and random board wedges when > the system idles and CPU cores clock down to lower opp points. Recent > vendor kernels include a change to remove 100-250MHz and other distro > sources also remove the 500/667MHz points. Unless all 100-667Mhz opps > are removed or the CPU governor forced to performance stalls are still > observed, so let's remove them to improve stability and uptime. > > Fixes: 3d9e76483049 ("arm64: dts: meson-sm1-sei610: enable DVFS") > Signed-off-by: Christian Hewitt <christianshewitt@gmail.com> > --- > arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 20 -------------------- > 1 file changed, 20 deletions(-) > > diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi > b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi > index 3c07a89bfd27..80737731af3f 100644 > --- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi > +++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi > @@ -95,26 +95,6 @@ > compatible = "operating-points-v2"; > opp-shared; > > - opp-100000000 { > - opp-hz = /bits/ 64 <100000000>; > - opp-microvolt = <730000>; > - }; > - > - opp-250000000 { > - opp-hz = /bits/ 64 <250000000>; > - opp-microvolt = <730000>; > - }; > - > - opp-500000000 { > - opp-hz = /bits/ 64 <500000000>; > - opp-microvolt = <730000>; > - }; > - > - opp-667000000 { > - opp-hz = /bits/ 64 <666666666>; > - opp-microvolt = <750000>; > - }; > - > opp-1000000000 { > opp-hz = /bits/ 64 <1000000000>; > opp-microvolt = <770000>; That's not nearly enough. If that's an actual issue, the driver should be updated not to use these OPPs, and you can't assume that people will just update their DT (mine comes from u-boot, and it is unlikely I will update it anytime soon). Thanks, M.
Hi Marc, On 10/02/2022 11:36, Marc Zyngier wrote: > On 2022-02-10 10:06, Christian Hewitt wrote: >> Amlogic SM1 devices experience CPU stalls and random board wedges when >> the system idles and CPU cores clock down to lower opp points. Recent >> vendor kernels include a change to remove 100-250MHz and other distro >> sources also remove the 500/667MHz points. Unless all 100-667Mhz opps >> are removed or the CPU governor forced to performance stalls are still >> observed, so let's remove them to improve stability and uptime. >> >> Fixes: 3d9e76483049 ("arm64: dts: meson-sm1-sei610: enable DVFS") >> Signed-off-by: Christian Hewitt <christianshewitt@gmail.com> >> --- >> arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 20 -------------------- >> 1 file changed, 20 deletions(-) >> >> diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi >> b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi >> index 3c07a89bfd27..80737731af3f 100644 >> --- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi >> +++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi >> @@ -95,26 +95,6 @@ >> compatible = "operating-points-v2"; >> opp-shared; >> >> - opp-100000000 { >> - opp-hz = /bits/ 64 <100000000>; >> - opp-microvolt = <730000>; >> - }; >> - >> - opp-250000000 { >> - opp-hz = /bits/ 64 <250000000>; >> - opp-microvolt = <730000>; >> - }; >> - >> - opp-500000000 { >> - opp-hz = /bits/ 64 <500000000>; >> - opp-microvolt = <730000>; >> - }; >> - >> - opp-667000000 { >> - opp-hz = /bits/ 64 <666666666>; >> - opp-microvolt = <750000>; >> - }; >> - >> opp-1000000000 { >> opp-hz = /bits/ 64 <1000000000>; >> opp-microvolt = <770000>; > > That's not nearly enough. If that's an actual issue, the driver > should be updated not to use these OPPs, and you can't assume > that people will just update their DT (mine comes from u-boot, > and it is unlikely I will update it anytime soon). The driver is the generic cpufreq and a generic clock driver, we do not filter out the possible OPP frequencies because the possible freq is large and depends on the die revision. I don't see why we should filter out these frequencies so far. Neil > > Thanks, > > M.
On 10/02/2022 11:06, Christian Hewitt wrote: > Amlogic SM1 devices experience CPU stalls and random board wedges when > the system idles and CPU cores clock down to lower opp points. Recent > vendor kernels include a change to remove 100-250MHz and other distro > sources also remove the 500/667MHz points. Unless all 100-667Mhz opps > are removed or the CPU governor forced to performance stalls are still > observed, so let's remove them to improve stability and uptime. > > Fixes: 3d9e76483049 ("arm64: dts: meson-sm1-sei610: enable DVFS") > Signed-off-by: Christian Hewitt <christianshewitt@gmail.com> > --- > arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 20 -------------------- > 1 file changed, 20 deletions(-) > > diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi > index 3c07a89bfd27..80737731af3f 100644 > --- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi > +++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi > @@ -95,26 +95,6 @@ > compatible = "operating-points-v2"; > opp-shared; > > - opp-100000000 { > - opp-hz = /bits/ 64 <100000000>; > - opp-microvolt = <730000>; > - }; > - > - opp-250000000 { > - opp-hz = /bits/ 64 <250000000>; > - opp-microvolt = <730000>; > - }; > - > - opp-500000000 { > - opp-hz = /bits/ 64 <500000000>; > - opp-microvolt = <730000>; > - }; > - > - opp-667000000 { > - opp-hz = /bits/ 64 <666666666>; > - opp-microvolt = <750000>; > - }; > - > opp-1000000000 { > opp-hz = /bits/ 64 <1000000000>; > opp-microvolt = <770000>; Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi index 3c07a89bfd27..80737731af3f 100644 --- a/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi +++ b/arch/arm64/boot/dts/amlogic/meson-sm1.dtsi @@ -95,26 +95,6 @@ compatible = "operating-points-v2"; opp-shared; - opp-100000000 { - opp-hz = /bits/ 64 <100000000>; - opp-microvolt = <730000>; - }; - - opp-250000000 { - opp-hz = /bits/ 64 <250000000>; - opp-microvolt = <730000>; - }; - - opp-500000000 { - opp-hz = /bits/ 64 <500000000>; - opp-microvolt = <730000>; - }; - - opp-667000000 { - opp-hz = /bits/ 64 <666666666>; - opp-microvolt = <750000>; - }; - opp-1000000000 { opp-hz = /bits/ 64 <1000000000>; opp-microvolt = <770000>;
Amlogic SM1 devices experience CPU stalls and random board wedges when the system idles and CPU cores clock down to lower opp points. Recent vendor kernels include a change to remove 100-250MHz and other distro sources also remove the 500/667MHz points. Unless all 100-667Mhz opps are removed or the CPU governor forced to performance stalls are still observed, so let's remove them to improve stability and uptime. Fixes: 3d9e76483049 ("arm64: dts: meson-sm1-sei610: enable DVFS") Signed-off-by: Christian Hewitt <christianshewitt@gmail.com> --- arch/arm64/boot/dts/amlogic/meson-sm1.dtsi | 20 -------------------- 1 file changed, 20 deletions(-)