Re: [PATCH] ARM: multi_v7_defconfig: switch CONFIG_PWM_MESON to built-in
Martin Blumenstingl writes: > Hi Kevin, > > On Fri, Nov 30, 2018 at 12:28 AM Kevin Hilman wrote: >> >> Martin Blumenstingl writes: >> >> > Hi Kevin, >> > >> > On Thu, Nov 29, 2018 at 1:30 AM Kevin Hilman wrote: >> >> >> >> Martin Blumenstingl writes: >> >> >> >> > Some Meson8b boards (Odroid-C1, EC-100) use a PWM regulator which is the >> >> > voltage supply of the CPU cores (this regulator is typically called >> >> > "VCCK"). >> >> > Now that we are preparing support for CPU frequency scaling on Meson8, >> >> > Meson8b and Meson8m2 we should build the pwm-meson driver into the >> >> > kernel so we can configure the CPU voltage early in the boot process. >> >> >> >> Can you explain a little more why the configuration of CPU voltage >> >> cannot wait a bit so this could be properly probed? >> > >> > I was under the impression that cpufreq-dt would still initialize even >> > if the regulator is not ready yet. however (after reading the code >> > again) this is clearly NOT the case. >> >> Hmm, a quick look at cpufreq-dt suggests that it should -EPROBE_DEFER if >> the regulator isn't ready yet. Why doesn't that work? > sorry for not being clear: > I was under the impression that cpufreq-dt wouldn't handle -EPROBE_DEFER. > I'm not sure why I assumed that. As you already said: deferred probing > of the regulator works fine. > >> > there's still a benefit with this change: your Odroid-C1 in your >> > KernelCI lab would also be able to change the CPU frequency (so in >> > case something breaks we could spot it there). >> > will you accept this patch after I updated the description to mention >> > that it's for KernelCI test coverage? >> >> Possibly, but I'd still rather see the dependencies worked out correctly >> so that this can be module, and cpufreq-dt would defer until it's ready. > KernelCI shows multiple "pwm-regulator regulator-vcck: Failed to get > PWM: -517" messages on Odroid-C1. > however, what I failed to notice so far is that there's a > "pwm-regulator: supplied by regulator-dummy" at the end of the boot > process. does this mean that the Odroid-C1 in your KernelCI lab can > load kernel modules? in that case this patch can be ignored. All boards in my lab can load modules. The boot with a minimal buildroot-based ramdisk that uses eudev, so any drivers that are present in DT will be loaded (if they're modules) or probed. > (I will still send a PWM regulator related patch: that "Failed to get > PWM: -517" message is very noisy and we typically suppress that in > other drivers) Sure, no objections to that one. Kevin
Re: [PATCH] ARM: multi_v7_defconfig: switch CONFIG_PWM_MESON to built-in
Martin Blumenstingl writes: > Hi Kevin, > > On Fri, Nov 30, 2018 at 12:28 AM Kevin Hilman wrote: >> >> Martin Blumenstingl writes: >> >> > Hi Kevin, >> > >> > On Thu, Nov 29, 2018 at 1:30 AM Kevin Hilman wrote: >> >> >> >> Martin Blumenstingl writes: >> >> >> >> > Some Meson8b boards (Odroid-C1, EC-100) use a PWM regulator which is the >> >> > voltage supply of the CPU cores (this regulator is typically called >> >> > "VCCK"). >> >> > Now that we are preparing support for CPU frequency scaling on Meson8, >> >> > Meson8b and Meson8m2 we should build the pwm-meson driver into the >> >> > kernel so we can configure the CPU voltage early in the boot process. >> >> >> >> Can you explain a little more why the configuration of CPU voltage >> >> cannot wait a bit so this could be properly probed? >> > >> > I was under the impression that cpufreq-dt would still initialize even >> > if the regulator is not ready yet. however (after reading the code >> > again) this is clearly NOT the case. >> >> Hmm, a quick look at cpufreq-dt suggests that it should -EPROBE_DEFER if >> the regulator isn't ready yet. Why doesn't that work? > sorry for not being clear: > I was under the impression that cpufreq-dt wouldn't handle -EPROBE_DEFER. > I'm not sure why I assumed that. As you already said: deferred probing > of the regulator works fine. > >> > there's still a benefit with this change: your Odroid-C1 in your >> > KernelCI lab would also be able to change the CPU frequency (so in >> > case something breaks we could spot it there). >> > will you accept this patch after I updated the description to mention >> > that it's for KernelCI test coverage? >> >> Possibly, but I'd still rather see the dependencies worked out correctly >> so that this can be module, and cpufreq-dt would defer until it's ready. > KernelCI shows multiple "pwm-regulator regulator-vcck: Failed to get > PWM: -517" messages on Odroid-C1. > however, what I failed to notice so far is that there's a > "pwm-regulator: supplied by regulator-dummy" at the end of the boot > process. does this mean that the Odroid-C1 in your KernelCI lab can > load kernel modules? in that case this patch can be ignored. All boards in my lab can load modules. The boot with a minimal buildroot-based ramdisk that uses eudev, so any drivers that are present in DT will be loaded (if they're modules) or probed. > (I will still send a PWM regulator related patch: that "Failed to get > PWM: -517" message is very noisy and we typically suppress that in > other drivers) Sure, no objections to that one. Kevin
Re: [PATCH] ARM: multi_v7_defconfig: switch CONFIG_PWM_MESON to built-in
Hi Kevin, On Fri, Nov 30, 2018 at 12:28 AM Kevin Hilman wrote: > > Martin Blumenstingl writes: > > > Hi Kevin, > > > > On Thu, Nov 29, 2018 at 1:30 AM Kevin Hilman wrote: > >> > >> Martin Blumenstingl writes: > >> > >> > Some Meson8b boards (Odroid-C1, EC-100) use a PWM regulator which is the > >> > voltage supply of the CPU cores (this regulator is typically called > >> > "VCCK"). > >> > Now that we are preparing support for CPU frequency scaling on Meson8, > >> > Meson8b and Meson8m2 we should build the pwm-meson driver into the > >> > kernel so we can configure the CPU voltage early in the boot process. > >> > >> Can you explain a little more why the configuration of CPU voltage > >> cannot wait a bit so this could be properly probed? > > > > I was under the impression that cpufreq-dt would still initialize even > > if the regulator is not ready yet. however (after reading the code > > again) this is clearly NOT the case. > > Hmm, a quick look at cpufreq-dt suggests that it should -EPROBE_DEFER if > the regulator isn't ready yet. Why doesn't that work? sorry for not being clear: I was under the impression that cpufreq-dt wouldn't handle -EPROBE_DEFER. I'm not sure why I assumed that. As you already said: deferred probing of the regulator works fine. > > there's still a benefit with this change: your Odroid-C1 in your > > KernelCI lab would also be able to change the CPU frequency (so in > > case something breaks we could spot it there). > > will you accept this patch after I updated the description to mention > > that it's for KernelCI test coverage? > > Possibly, but I'd still rather see the dependencies worked out correctly > so that this can be module, and cpufreq-dt would defer until it's ready. KernelCI shows multiple "pwm-regulator regulator-vcck: Failed to get PWM: -517" messages on Odroid-C1. however, what I failed to notice so far is that there's a "pwm-regulator: supplied by regulator-dummy" at the end of the boot process. does this mean that the Odroid-C1 in your KernelCI lab can load kernel modules? in that case this patch can be ignored. (I will still send a PWM regulator related patch: that "Failed to get PWM: -517" message is very noisy and we typically suppress that in other drivers) Regards Martin
Re: [PATCH] ARM: multi_v7_defconfig: switch CONFIG_PWM_MESON to built-in
Hi Kevin, On Fri, Nov 30, 2018 at 12:28 AM Kevin Hilman wrote: > > Martin Blumenstingl writes: > > > Hi Kevin, > > > > On Thu, Nov 29, 2018 at 1:30 AM Kevin Hilman wrote: > >> > >> Martin Blumenstingl writes: > >> > >> > Some Meson8b boards (Odroid-C1, EC-100) use a PWM regulator which is the > >> > voltage supply of the CPU cores (this regulator is typically called > >> > "VCCK"). > >> > Now that we are preparing support for CPU frequency scaling on Meson8, > >> > Meson8b and Meson8m2 we should build the pwm-meson driver into the > >> > kernel so we can configure the CPU voltage early in the boot process. > >> > >> Can you explain a little more why the configuration of CPU voltage > >> cannot wait a bit so this could be properly probed? > > > > I was under the impression that cpufreq-dt would still initialize even > > if the regulator is not ready yet. however (after reading the code > > again) this is clearly NOT the case. > > Hmm, a quick look at cpufreq-dt suggests that it should -EPROBE_DEFER if > the regulator isn't ready yet. Why doesn't that work? sorry for not being clear: I was under the impression that cpufreq-dt wouldn't handle -EPROBE_DEFER. I'm not sure why I assumed that. As you already said: deferred probing of the regulator works fine. > > there's still a benefit with this change: your Odroid-C1 in your > > KernelCI lab would also be able to change the CPU frequency (so in > > case something breaks we could spot it there). > > will you accept this patch after I updated the description to mention > > that it's for KernelCI test coverage? > > Possibly, but I'd still rather see the dependencies worked out correctly > so that this can be module, and cpufreq-dt would defer until it's ready. KernelCI shows multiple "pwm-regulator regulator-vcck: Failed to get PWM: -517" messages on Odroid-C1. however, what I failed to notice so far is that there's a "pwm-regulator: supplied by regulator-dummy" at the end of the boot process. does this mean that the Odroid-C1 in your KernelCI lab can load kernel modules? in that case this patch can be ignored. (I will still send a PWM regulator related patch: that "Failed to get PWM: -517" message is very noisy and we typically suppress that in other drivers) Regards Martin
Re: [PATCH] ARM: multi_v7_defconfig: switch CONFIG_PWM_MESON to built-in
Martin Blumenstingl writes: > Hi Kevin, > > On Thu, Nov 29, 2018 at 1:30 AM Kevin Hilman wrote: >> >> Martin Blumenstingl writes: >> >> > Some Meson8b boards (Odroid-C1, EC-100) use a PWM regulator which is the >> > voltage supply of the CPU cores (this regulator is typically called >> > "VCCK"). >> > Now that we are preparing support for CPU frequency scaling on Meson8, >> > Meson8b and Meson8m2 we should build the pwm-meson driver into the >> > kernel so we can configure the CPU voltage early in the boot process. >> >> Can you explain a little more why the configuration of CPU voltage >> cannot wait a bit so this could be properly probed? > > I was under the impression that cpufreq-dt would still initialize even > if the regulator is not ready yet. however (after reading the code > again) this is clearly NOT the case. Hmm, a quick look at cpufreq-dt suggests that it should -EPROBE_DEFER if the regulator isn't ready yet. Why doesn't that work? > there's still a benefit with this change: your Odroid-C1 in your > KernelCI lab would also be able to change the CPU frequency (so in > case something breaks we could spot it there). > will you accept this patch after I updated the description to mention > that it's for KernelCI test coverage? Possibly, but I'd still rather see the dependencies worked out correctly so that this can be module, and cpufreq-dt would defer until it's ready. Kevin
Re: [PATCH] ARM: multi_v7_defconfig: switch CONFIG_PWM_MESON to built-in
Martin Blumenstingl writes: > Hi Kevin, > > On Thu, Nov 29, 2018 at 1:30 AM Kevin Hilman wrote: >> >> Martin Blumenstingl writes: >> >> > Some Meson8b boards (Odroid-C1, EC-100) use a PWM regulator which is the >> > voltage supply of the CPU cores (this regulator is typically called >> > "VCCK"). >> > Now that we are preparing support for CPU frequency scaling on Meson8, >> > Meson8b and Meson8m2 we should build the pwm-meson driver into the >> > kernel so we can configure the CPU voltage early in the boot process. >> >> Can you explain a little more why the configuration of CPU voltage >> cannot wait a bit so this could be properly probed? > > I was under the impression that cpufreq-dt would still initialize even > if the regulator is not ready yet. however (after reading the code > again) this is clearly NOT the case. Hmm, a quick look at cpufreq-dt suggests that it should -EPROBE_DEFER if the regulator isn't ready yet. Why doesn't that work? > there's still a benefit with this change: your Odroid-C1 in your > KernelCI lab would also be able to change the CPU frequency (so in > case something breaks we could spot it there). > will you accept this patch after I updated the description to mention > that it's for KernelCI test coverage? Possibly, but I'd still rather see the dependencies worked out correctly so that this can be module, and cpufreq-dt would defer until it's ready. Kevin
Re: [PATCH] ARM: multi_v7_defconfig: switch CONFIG_PWM_MESON to built-in
Hi Kevin, On Thu, Nov 29, 2018 at 1:30 AM Kevin Hilman wrote: > > Martin Blumenstingl writes: > > > Some Meson8b boards (Odroid-C1, EC-100) use a PWM regulator which is the > > voltage supply of the CPU cores (this regulator is typically called > > "VCCK"). > > Now that we are preparing support for CPU frequency scaling on Meson8, > > Meson8b and Meson8m2 we should build the pwm-meson driver into the > > kernel so we can configure the CPU voltage early in the boot process. > > Can you explain a little more why the configuration of CPU voltage > cannot wait a bit so this could be properly probed? I was under the impression that cpufreq-dt would still initialize even if the regulator is not ready yet. however (after reading the code again) this is clearly NOT the case. there's still a benefit with this change: your Odroid-C1 in your KernelCI lab would also be able to change the CPU frequency (so in case something breaks we could spot it there). will you accept this patch after I updated the description to mention that it's for KernelCI test coverage? Regards Martin
Re: [PATCH] ARM: multi_v7_defconfig: switch CONFIG_PWM_MESON to built-in
Hi Kevin, On Thu, Nov 29, 2018 at 1:30 AM Kevin Hilman wrote: > > Martin Blumenstingl writes: > > > Some Meson8b boards (Odroid-C1, EC-100) use a PWM regulator which is the > > voltage supply of the CPU cores (this regulator is typically called > > "VCCK"). > > Now that we are preparing support for CPU frequency scaling on Meson8, > > Meson8b and Meson8m2 we should build the pwm-meson driver into the > > kernel so we can configure the CPU voltage early in the boot process. > > Can you explain a little more why the configuration of CPU voltage > cannot wait a bit so this could be properly probed? I was under the impression that cpufreq-dt would still initialize even if the regulator is not ready yet. however (after reading the code again) this is clearly NOT the case. there's still a benefit with this change: your Odroid-C1 in your KernelCI lab would also be able to change the CPU frequency (so in case something breaks we could spot it there). will you accept this patch after I updated the description to mention that it's for KernelCI test coverage? Regards Martin
Re: [PATCH] ARM: multi_v7_defconfig: switch CONFIG_PWM_MESON to built-in
Martin Blumenstingl writes: > Some Meson8b boards (Odroid-C1, EC-100) use a PWM regulator which is the > voltage supply of the CPU cores (this regulator is typically called > "VCCK"). > Now that we are preparing support for CPU frequency scaling on Meson8, > Meson8b and Meson8m2 we should build the pwm-meson driver into the > kernel so we can configure the CPU voltage early in the boot process. Can you explain a little more why the configuration of CPU voltage cannot wait a bit so this could be properly probed? Kevin
Re: [PATCH] ARM: multi_v7_defconfig: switch CONFIG_PWM_MESON to built-in
Martin Blumenstingl writes: > Some Meson8b boards (Odroid-C1, EC-100) use a PWM regulator which is the > voltage supply of the CPU cores (this regulator is typically called > "VCCK"). > Now that we are preparing support for CPU frequency scaling on Meson8, > Meson8b and Meson8m2 we should build the pwm-meson driver into the > kernel so we can configure the CPU voltage early in the boot process. Can you explain a little more why the configuration of CPU voltage cannot wait a bit so this could be properly probed? Kevin
