awful kconfig help texts.
PWM Support (PWM) [N/y/?] (NEW) ?
CONFIG_PWM:
This enables PWM support through the generic PWM framework.
Well that's.. enlightening. I'm picking on PWM here, but this isn't an isolated case. Every merge window we see a slew of new options with useless help texts. They may as well be non-existent. (Actually in some cases, they are).
If someone has to read the code to find out what the driver is, your help text probably sucks.
(I'll leave "why does this option even show up on x86" as a separate rant)
Dave
Quoted 9 lines · Dave Jones
PWM Support (PWM) [N/y/?] (NEW) ?
CONFIG_PWM:This enables PWM support through the generic PWM framework.
Well that's.. enlightening.
Oh, there's one more enlightening sentence in the help:
"You only need to enable this, if you also want to enable one or more of the PWM drivers below."
Got it? :-)
Quoted 8 lines
I'm picking on PWM here, but this isn't an
isolated case. Every merge window we see a slew of new options with useless help texts. They may as well be non-existent. (Actually in some cases, they are).If someone has to read the code to find out what the driver is, your help text probably sucks.
(I'll leave "why does this option even show up on x86" as a separate rant)
Thierry, can you guys please fix this?
Thanks.
Signature · 2 lines
Regards/Gruss, Boris.
Quoted 9 lines · Borislav Petkov
Quoted 8 lines · Dave Jones
PWM Support (PWM) [N/y/?] (NEW) ?
CONFIG_PWM:This enables PWM support through the generic PWM framework.
Quoted 6 lines
Quoted 1 line
Well that's.. enlightening.
Oh, there's one more enlightening sentence in the help:
"You only need to enable this, if you also want to enable one or more of the PWM drivers below."
Then shouldn't this not have a prompt and just be selected by those PWM drivers below?
Quoted 11 lines
Got it? :-)
Quoted 8 lines
I'm picking on PWM here, but this isn't an
isolated case. Every merge window we see a slew of new options with useless help texts. They may as well be non-existent. (Actually in some cases, they are).If someone has to read the code to find out what the driver is, your help text probably sucks.
(I'll leave "why does this option even show up on x86" as a separate rant)
/me is looking forward to this rant ;-)
-- Steve
Quoted 2 lines · Steven Rostedt
Then shouldn't this not have a prompt and just be selected by those PWM drivers below?
It gives an empty menu due to the deps of the single PWM drivers.
But the whole CONFIG_PWM thing should simply depend on !X86 so that it doesn't appear in drivers/.
Signature · 2 lines
Regards/Gruss, Boris.
Quoted 9 lines · Borislav Petkov
Quoted 8 lines · Dave Jones
PWM Support (PWM) [N/y/?] (NEW) ?
CONFIG_PWM:This enables PWM support through the generic PWM framework.
Quoted 8 lines
Quoted 1 line
Well that's.. enlightening.
Oh, there's one more enlightening sentence in the help:
"You only need to enable this, if you also want to enable one or more of the PWM drivers below."
Got it? :-)
No, it doesn't add anything useful at all.
I know PWM is probably pulse width modulation, but why would my kernel need to care about this ? Why would I need drivers for it ?
Also, think about what happens with 'oldconfig'. You don't get to even see 'the drivers below' until you've answered this question.
It couldn't be more opaque if it tried.
Dave
Quoted 9 lines · Dave Jones
Quoted 6 lines · Borislav Petkov
Oh, there's one more enlightening sentence in the help:
"You only need to enable this, if you also want to enable one or more of the PWM drivers below."
Got it? :-)
No, it doesn't add anything useful at all.
Sorry, I think you misunderstood me and I didn't express my irony adequately - I was trying to be ironic, maybe even sarcastic here. But that's hard to convey in written form.
Quoted 7 lines
I know PWM is probably pulse width modulation, but why would my kernel need to care about this ? Why would I need drivers for it ?
Also, think about what happens with 'oldconfig'. You don't get to even see 'the drivers below' until you've answered this question.
It couldn't be more opaque if it tried.
I agree with all you've said and you're preaching to the choir. Sorry that I didn't make my sarcasm more explicit.
Thanks.
Signature · 2 lines
Regards/Gruss,
Boris.Quoted 22 lines · Borislav Petkov
Quoted 9 lines · Dave Jones
PWM Support (PWM) [N/y/?] (NEW) ?
CONFIG_PWM:This enables PWM support through the generic PWM framework.
Well that's.. enlightening.
Oh, there's one more enlightening sentence in the help:
"You only need to enable this, if you also want to enable one or more of the PWM drivers below."
Got it? :-)
Quoted 4 lines
I'm picking on PWM here, but this isn't an
isolated case. Every merge window we see a slew of new options with useless help texts. They may as well be non-existent. (Actually in some cases, they are).
Quoted 6 lines
Quoted 4 lines
If someone has to read the code to find out what the driver is, your help text probably sucks.
(I'll leave "why does this option even show up on x86" as a separate rant)
Thierry, can you guys please fix this?
Hehe, those aren't very descriptive, that's true. I was going to go over the documentation anyway, so I'll make a note to revise the Kconfig help texts as well.
Thierry
Quoted 8 lines · Borislav Petkov
Quoted 2 lines · Steven Rostedt
Then shouldn't this not have a prompt and just be selected by those PWM drivers below?
It gives an empty menu due to the deps of the single PWM drivers.
But the whole
CONFIG_PWMthing should simply depend on !X86 so that it doesn't appear indrivers/.
I don't think that's a good idea. That would mean I would have to add !SPARC and !S390 and many other to that list as well. Also there are a couple of drivers that are in the process of being ported which are not restricted to ARM or embedded in general. So even if we make this !X86 now, eventually it will pop up again.
Thierry
Quoted 7 lines · Thierry Reding
Quoted 6 lines · Borislav Petkov
Quoted 2 lines · Steven Rostedt
Then shouldn't this not have a prompt and just be selected by those PWM drivers below?
It gives an empty menu due to the deps of the single PWM drivers.
Quoted 8 lines
Quoted 2 lines
But the whole
CONFIG_PWMthing should simply depend on !X86 so that it doesn't appear indrivers/.I don't think that's a good idea. That would mean I would have to add !SPARC and !S390 and many other to that list as well. Also there are a couple of drivers that are in the process of being ported which are not restricted to ARM or embedded in general. So even if we make this !X86 now, eventually it will pop up again.
Hmm, how about having a synthetic define CONFIG_ARCH_PWM and each arch which has such a driver can select it and then CONFIG_PWM would depend on that. Would that even work?
Signature · 2 lines
Regards/Gruss,
Boris.Quoted 17 lines · Borislav Petkov
Quoted 7 lines · Thierry Reding
Quoted 6 lines · Borislav Petkov
Quoted 2 lines · Steven Rostedt
Then shouldn't this not have a prompt and just be selected by those PWM drivers below?
It gives an empty menu due to the deps of the single PWM drivers.
Quoted 8 lines
Quoted 2 lines
But the whole
CONFIG_PWMthing should simply depend on !X86 so that it doesn't appear indrivers/.I don't think that's a good idea. That would mean I would have to add !SPARC and !S390 and many other to that list as well. Also there are a couple of drivers that are in the process of being ported which are not restricted to ARM or embedded in general. So even if we make this !X86 now, eventually it will pop up again.
Quoted 4 lines
Hmm, how about having a synthetic define
CONFIG_ARCH_PWMand each arch which has such a driver can select it and thenCONFIG_PWMwould depend on that. Would that even work?
One major reason for the new PWM framework is to be able to support arch independent PWM drivers, like those for companion chips with PWM capabilities. Restricting the config option to certain architectures wouldn't work.
- Lars
Quoted 4 lines · Lars-Peter Clausen
One major reason for the new PWM framework is to be able to support arch independent PWM drivers, like those for companion chips with PWM capabilities. Restricting the config option to certain architectures wouldn't work.
Right,
but when I enable the CONFIG_PWM option on x86, I don't see any drivers there. So the logical thing to do would be to hide that option on arches which don't have such chips.
Signature · 2 lines
Regards/Gruss,
Boris.Quoted 11 lines · Thierry Reding
Quoted 11 lines
Quoted 5 lines
PWM Support (PWM) [N/y/?] (NEW) ?
CONFIG_PWM:
This enables PWM support through the generic PWM framework.Oh, there's one more enlightening sentence in the help:
"You only need to enable this, if you also want to enable one or more of the PWM drivers below."
Quoted 6 lines
Quoted 2 lines
Got it? :-)
Thierry, can you guys please fix this?Hehe, those aren't very descriptive, that's true. I was going to go over the documentation anyway, so I'll make a note to revise the
Kconfighelp texts as well.
Also, instead of
bool "PWM Support"
this should be
menuconfig "PWM support"
so that you can disable the whole submenu at once.
Quoted 11 lines · Borislav Petkov
Quoted 4 lines · Lars-Peter Clausen
One major reason for the new PWM framework is to be able to support arch independent PWM drivers, like those for companion chips with PWM capabilities. Restricting the config option to certain architectures wouldn't work.
Right,
but when I enable the
CONFIG_PWMoption on x86, I don't see any drivers there. So the logical thing to do would be to hide that option on arches which don't have such chips.
You don't see any drivers, because the subsystem is still young and no such arch independent drivers have been added yet, but they will get added in the future. The arch independent companion or PWM expander chips usually interface via I2S or SPI and I would consider it quite likely that you'll also find them on some embedded X86 boards. If we add a arch restriction to the config item now we'd quite likely have to remove it again in the next release.
Quoted 7 lines · Lars-Peter Clausen
You don't see any drivers, because the subsystem is still young and no such arch independent drivers have been added yet, but they will get added in the future. The arch independent companion or PWM expander chips usually interface via I2S or SPI and I would consider it quite likely that you'll also find them on some embedded X86 boards. If we add a arch restriction to the config item now we'd quite likely have to remove it again in the next release.
Yes please.
Kconfig is overcrowded as it is now and adding yet another option which is irrelevant for some arches (for now, as you say) simply causes confusion to people with absolutely no gain.
Simply take a look at all arch/<archname>/Kconfig files and look at all the "select ..." statements right at the beginning of the respective Kconfig file.
Each arch which has PWM drivers would select the synthetic CONFIG_ARCH_PWM option and CONFIG_PWM would depend on it.
Signature · 2 lines
Regards/Gruss,
Boris.Quoted 11 lines · Borislav Petkov
Quoted 7 lines · Lars-Peter Clausen
You don't see any drivers, because the subsystem is still young and no such arch independent drivers have been added yet, but they will get added in the future. The arch independent companion or PWM expander chips usually interface via I2S or SPI and I would consider it quite likely that you'll also find them on some embedded X86 boards. If we add a arch restriction to the config item now we'd quite likely have to remove it again in the next release.
Yes please.
Quoted 7 lines
Kconfigis overcrowded as it is now and adding yet another option which is irrelevant for some arches (for now, as you say) simply causes confusion to people with absolutely no gain.Simply take a look at all arch/<archname>/Kconfig files and look at all the "select ..." statements right at the beginning of the respective
Kconfigfile.
Yes and these select statements make sense, what you suggest though doesn't, at least from my point of view. What you want is that you don't get presented the option to select the PWM system if there no PWM driver available based on your other config options. But whether a PWM driver is available or not is not a issue of which arch you are building for.
You could do that by using a construct like below, but well...
config HAS_PWM
bool
config PWM
bool "PWM
depends on HAS_PWM
config PWM_CAN_BUILD_DRIVER_X
defbool I2C
select HAS_PWM
config PWM_DRIVER_X
tristate "PWM chip X support"
depends on PWM && PWM_CAN_BUILD_DRIVER_X
config PWM_CAN_BUILD_DRIVER_Y
defbool ARCH_Y
select HAS_PWM
config PWM_DRIVER_Y
tristate "PWM chip Y support"
depends on PWM && PWM_CAN_BUILD_DRIVER_Y
Quoted 17 lines · Lars-Peter Clausen
You could do that by using a construct like below, but well...
config
HAS_PWM
boolconfig PWM
bool "PWM
depends onHAS_PWMconfig
PWM_CAN_BUILD_DRIVER_X
defbool I2C
selectHAS_PWMconfig
PWM_DRIVER_X
tristate "PWM chip X support"
depends on PWM &&PWM_CAN_BUILD_DRIVER_X
Quoted 7 lines
config
PWM_CAN_BUILD_DRIVER_Y
defboolARCH_Y
selectHAS_PWMconfig
PWM_DRIVER_Y
tristate "PWM chip Y support"
depends on PWM &&PWM_CAN_BUILD_DRIVER_Y
What selects the 'PWM_CAN_BUILD_DRIVER_FOO'?
-- Steve
Quoted 23 lines · Steven Rostedt
Quoted 21 lines · Lars-Peter Clausen
You could do that by using a construct like below, but well...
config
HAS_PWM
boolconfig PWM
bool "PWM
depends onHAS_PWMconfig
PWM_CAN_BUILD_DRIVER_X
defbool I2C
selectHAS_PWMconfig
PWM_DRIVER_X
tristate "PWM chip X support"
depends on PWM &&PWM_CAN_BUILD_DRIVER_Xconfig
PWM_CAN_BUILD_DRIVER_Y
defboolARCH_Y
selectHAS_PWM
Quoted 6 lines
Quoted 3 lines
config
PWM_DRIVER_Y
tristate "PWM chip Y support"
depends on PWM &&PWM_CAN_BUILD_DRIVER_YWhat selects the '
PWM_CAN_BUILD_DRIVER_FOO'?
Its def_bool statement, which lists the prerequisites to build the driver. E.g. for a I2C PWM expander I2S support, for a on-SoC PWM core support for the SoC family, etc.. So it will be true if the driver can actually be built and false otherwise. If one of the PWM_CAN_BUILD_DRIVER_FOO symbols is true also HAS_PWM will be true and PWM becomes selectable.
But it seems to be a bid tedious to have these extra lines for each driver and I guess it is not a PWM subsystem specific issue. There are other subsystems where this probably applies as well, e.g. the MFD subsystem. Also such a solution would rule out out-of-tree PWM driver modules, since it is not possible to get CONFIG_PWM selected.
- Lars
Quoted 3 lines · Borislav Petkov
but when I enable the
CONFIG_PWMoption on x86, I don't see any drivers there. So the logical thing to do would be to hide that option on arches which don't have such chips.
That's because the subsystem was only just added. As soon as we get support for platform independant devices the situation will change (though you may need to turn on some MFD cores). This is an issue in general, Kconfig could perhaps be smarter about checking if the submenu is empty.
Quoted 22 lines · Borislav Petkov
Quoted 9 lines · Dave Jones
PWM Support (PWM) [N/y/?] (NEW) ?
CONFIG_PWM:This enables PWM support through the generic PWM framework.
Well that's.. enlightening.
Oh, there's one more enlightening sentence in the help:
"You only need to enable this, if you also want to enable one or more of the PWM drivers below."
Got it? :-)
Quoted 4 lines
I'm picking on PWM here, but this isn't an
isolated case. Every merge window we see a slew of new options with useless help texts. They may as well be non-existent. (Actually in some cases, they are).
Quoted 6 lines
Quoted 4 lines
If someone has to read the code to find out what the driver is, your help text probably sucks.
(I'll leave "why does this option even show up on x86" as a separate rant)
Thierry, can you guys please fix this?
How does the attached patch look?
Thierry
From cd3199b94e697cccd38766b4a60d2e91474d0539 Mon Sep 17 00:00:00 2001
From: Thierry Reding <[email protected]>
Date: Thu, 16 Aug 2012 08:01:21 +0200
Subject: [PATCH] pwm: Improve Kconfig help text
The Kconfig help text should help the user understand what functionality is provided by an option. This is especially true for new subsystems. An improved help text is provided by this commit in the hopes of clarifying the usefulness of the PWM framework.
--- drivers/pwm/Kconfig | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)
drivers/pwm/Kconfig +18 -6
@@ -1,12 +1,24 @@ menuconfig PWM - bool "PWM Support" + bool "Pulse-Width Modulation (PWM) Support" depends on !MACH_JZ4740 && !PUV3_PWM help - This enables PWM support through the generic PWM framework. - You only need to enable this, if you also want to enable - one or more of the PWM drivers below. - - If unsure, say N. + Generic Pulse-Width Modulation (PWM) support. + + This framework provides a generic interface to PWM devices + within the Linux kernel. On the driver side it provides an API + to register and unregister a PWM chip, an abstraction of a PWM + controller, that supports one or more PWM devices. Client + drivers can request PWM devices and use the generic framework + to configure as well as enable and disable them. + + The new generic framework replaces the legacy PWM framework + which allows only a single driver implementing the required + API. Not all legacy implementations have been ported to the + new framework yet. The new framework provides an API that is + backward compatible with the legacy framework so that existing + client drivers continue to work as expected. + + If unsure, say no. if PWM
Signature · 1 line
1.7.11.5
Quoted 41 lines · Thierry Reding
How does the attached patch look?
Thierry
From
cd3199b94e697cccd38766b4a60d2e91474d0539Mon Sep 17 00:00:00 2001
From: Thierry Reding <[email protected]>
Date: Thu, 16 Aug 2012 08:01:21 +0200
Subject: [PATCH] pwm: ImproveKconfighelp textThe
Kconfighelp text should help the user understand what functionality is provided by an option. This is especially true for new subsystems. An improved help text is provided by this commit in the hopes of clarifying the usefulness of the PWM framework.Signed-off-by Thierry Reding <[email protected]>--- drivers/pwm/Kconfig | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)drivers/pwm/Kconfig +8
-6@@ -1,12 +1,24 @@ menuconfig PWM - bool "PWM Support" + bool "Pulse-Width Modulation (PWM) Support" depends on !MACH_JZ4740 && !PUV3_PWM help - This enables PWM support through the generic PWM framework. - You only need to enable this, if you also want to enable - one or more of the PWM drivers below. - - If unsure, say N. + Generic Pulse-Width Modulation (PWM) support. + + This framework provides a generic interface to PWM devices + within the Linux kernel. On the driver side it provides an API + to register and unregister a PWM chip, an abstraction of a PWM + controller, that supports one or more PWM devices. Client + drivers can request PWM devices and use the generic framework
drivers/pwm/Kconfig line 21
Quoted 10 lines
drivers/pwm/Kconfig +10
-0+ to configure as well as enable and disable them. + + The new generic framework replaces the legacy PWM framework + which allows only a single driver implementing the required + API. Not all legacy implementations have been ported to the + new framework yet. The new framework provides an API that is + backward compatible with the legacy framework so that existing + client drivers continue to work as expected. + + If unsure, say no.
Yes, this is much better than what we had before. I'd suggest though, that instead of describing the high-level software design of the PWM subsystem, the text should be more addressed to the simple user like me who would like to know what this thing is and why do I want to enable it. Basically summarize what PWN devices are and what they're used for. I.e., https://en.wikipedia.org/wiki/Pulse-width_modulation#Applications
but in 4-5 lines of text.
IMHO, of course.
Thanks.
Signature · 2 lines
Regards/Gruss, Boris.
Quoted 61 lines · Borislav Petkov
Quoted 41 lines · Thierry Reding
How does the attached patch look?
Thierry
From
cd3199b94e697cccd38766b4a60d2e91474d0539Mon Sep 17 00:00:00 2001
From: Thierry Reding <[email protected]>
Date: Thu, 16 Aug 2012 08:01:21 +0200
Subject: [PATCH] pwm: ImproveKconfighelp textThe
Kconfighelp text should help the user understand what functionality is provided by an option. This is especially true for new subsystems. An improved help text is provided by this commit in the hopes of clarifying the usefulness of the PWM framework.Signed-off-by Thierry Reding <[email protected]>--- drivers/pwm/Kconfig | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)drivers/pwm/Kconfig +8
-6@@ -1,12 +1,24 @@ menuconfig PWM - bool "PWM Support" + bool "Pulse-Width Modulation (PWM) Support" depends on !MACH_JZ4740 && !PUV3_PWM help - This enables PWM support through the generic PWM framework. - You only need to enable this, if you also want to enable - one or more of the PWM drivers below. - - If unsure, say N. + Generic Pulse-Width Modulation (PWM) support. + + This framework provides a generic interface to PWM devices + within the Linux kernel. On the driver side it provides an API + to register and unregister a PWM chip, an abstraction of a PWM + controller, that supports one or more PWM devices. Client + drivers can request PWM devices and use the generic frameworkdrivers/pwm/Kconfig line 21
Quoted 10 lines
drivers/pwm/Kconfig +10
-0+ to configure as well as enable and disable them. + + The new generic framework replaces the legacy PWM framework + which allows only a single driver implementing the required + API. Not all legacy implementations have been ported to the + new framework yet. The new framework provides an API that is + backward compatible with the legacy framework so that existing + client drivers continue to work as expected. + + If unsure, say no.Yes, this is much better than what we had before. I'd suggest though, that instead of describing the high-level software design of the PWM subsystem, the text should be more addressed to the simple user like me who would like to know what this thing is and why do I want to enable it. Basically summarize what PWN devices are and what they're used for. I.e., https://en.wikipedia.org/wiki/Pulse-width_modulation#Applications
but in 4-5 lines of text.
Quoted 1 line
IMHO, of course.
Okay, I'll add something along those lines in addition to the above. That way everybody should find something useful in it.
Thanks,
Thierry
Quoted 62 lines · Thierry Reding
Quoted 61 lines · Borislav Petkov
Quoted 41 lines · Thierry Reding
How does the attached patch look?
Thierry
From
cd3199b94e697cccd38766b4a60d2e91474d0539Mon Sep 17 00:00:00 2001
From: Thierry Reding <[email protected]>
Date: Thu, 16 Aug 2012 08:01:21 +0200
Subject: [PATCH] pwm: ImproveKconfighelp textThe
Kconfighelp text should help the user understand what functionality is provided by an option. This is especially true for new subsystems. An improved help text is provided by this commit in the hopes of clarifying the usefulness of the PWM framework.Signed-off-by Thierry Reding <[email protected]>--- drivers/pwm/Kconfig | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)drivers/pwm/Kconfig +8
-6@@ -1,12 +1,24 @@ menuconfig PWM - bool "PWM Support" + bool "Pulse-Width Modulation (PWM) Support" depends on !MACH_JZ4740 && !PUV3_PWM help - This enables PWM support through the generic PWM framework. - You only need to enable this, if you also want to enable - one or more of the PWM drivers below. - - If unsure, say N. + Generic Pulse-Width Modulation (PWM) support. + + This framework provides a generic interface to PWM devices + within the Linux kernel. On the driver side it provides an API + to register and unregister a PWM chip, an abstraction of a PWM + controller, that supports one or more PWM devices. Client + drivers can request PWM devices and use the generic frameworkdrivers/pwm/Kconfig line 21
Quoted 10 lines
drivers/pwm/Kconfig +10
-0+ to configure as well as enable and disable them. + + The new generic framework replaces the legacy PWM framework + which allows only a single driver implementing the required + API. Not all legacy implementations have been ported to the + new framework yet. The new framework provides an API that is + backward compatible with the legacy framework so that existing + client drivers continue to work as expected. + + If unsure, say no.Yes, this is much better than what we had before. I'd suggest though, that instead of describing the high-level software design of the PWM subsystem, the text should be more addressed to the simple user like me who would like to know what this thing is and why do I want to enable it. Basically summarize what PWN devices are and what they're used for. I.e., https://en.wikipedia.org/wiki/Pulse-width_modulation#Applications
but in 4-5 lines of text.
Quoted 4 lines
Quoted 1 line
IMHO, of course.
Okay, I'll add something along those lines in addition to the above. That way everybody should find something useful in it.
How about the patch below?
Thierry
From deb6852dc5e9da365a33c744f2dc107ae11b407a Mon Sep 17 00:00:00 2001
From: Thierry Reding <[email protected]>
Date: Thu, 16 Aug 2012 08:01:21 +0200
Subject: [PATCH v2] pwm: Improve Kconfig help text
The Kconfig help text should help the user understand what functionality is provided by an option. This is especially true for new subsystems. An improved help text is provided by this commit in the hopes of clarifying the usefulness of the PWM framework.
--- drivers/pwm/Kconfig | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-)
drivers/pwm/Kconfig +25 -6
@@ -1,12 +1,31 @@ menuconfig PWM - bool "PWM Support" + bool "Pulse-Width Modulation (PWM) Support" depends on !MACH_JZ4740 && !PUV3_PWM help - This enables PWM support through the generic PWM framework. - You only need to enable this, if you also want to enable - one or more of the PWM drivers below. - - If unsure, say N. + Generic Pulse-Width Modulation (PWM) support. + + In Pulse-Width Modulation, a variation of the width of pulses + in a rectangular pulse signal is used as a means to alter the + average power of the signal. Applications include efficient + power delivery and voltage regulation. In computer systems, + PWMs are commonly used to control fans or the brightness of + display backlights. + + This framework provides a generic interface to PWM devices + within the Linux kernel. On the driver side it provides an API + to register and unregister a PWM chip, an abstraction of a PWM + controller, that supports one or more PWM devices. Client + drivers can request PWM devices and use the generic framework + to configure as well as enable and disable them. + + The new generic framework replaces the legacy PWM framework + which allows only a single driver implementing the required + API. Not all legacy implementations have been ported to the + new framework yet. The new framework provides an API that is + backward compatible with the legacy framework so that existing + client drivers continue to work as expected. + + If unsure, say no. if PWM
Signature · 1 line
1.7.11.5
Borislav Petkov
Acked-byQuoted 9 lines · Thierry Reding
How about the patch below?
Thierry
From
deb6852dc5e9da365a33c744f2dc107ae11b407aMon Sep 17 00:00:00 2001
From: Thierry Reding <[email protected]>
Date: Thu, 16 Aug 2012 08:01:21 +0200
Subject: [PATCH v2] pwm: ImproveKconfighelp text
Quoted 6 lines
The
Kconfighelp text should help the user understand what functionality is provided by an option. This is especially true for new subsystems. An improved help text is provided by this commit in the hopes of clarifying the usefulness of the PWM framework.Signed-off-by Thierry Reding <[email protected]>
Absolutely! Now even I understand it :-).
Thanks.
Signature · 2 lines
Regards/Gruss,
Boris.Quoted 15 lines · Borislav Petkov
Quoted 14 lines · Thierry Reding
How about the patch below?
Thierry
From
deb6852dc5e9da365a33c744f2dc107ae11b407aMon Sep 17 00:00:00 2001
From: Thierry Reding <[email protected]>
Date: Thu, 16 Aug 2012 08:01:21 +0200
Subject: [PATCH v2] pwm: ImproveKconfighelp textThe
Kconfighelp text should help the user understand what functionality is provided by an option. This is especially true for new subsystems. An improved help text is provided by this commit in the hopes of clarifying the usefulness of the PWM framework.
Quoted 5 lines
Quoted 1 line
Signed-off-by Thierry Reding <[email protected]>Absolutely! Now even I understand it :-).
Acked-by Borislav Petkov <[email protected]>
Thanks, I'll queue this for 3.6-rc3.
Thierry
Quoted 15 lines
How about the patch below?
[...]
drivers/pwm/Kconfig +12
-0+ Generic Pulse-Width Modulation (PWM) support. + + In Pulse-Width Modulation, a variation of the width of pulses + in a rectangular pulse signal is used as a means to alter the + average power of the signal. Applications include efficient + power delivery and voltage regulation. In computer systems, + PWMs are commonly used to control fans or the brightness of + display backlights. + + This framework provides a generic interface to PWM devices + within the Linux kernel. On the driver side it provides an API + to register and unregister a PWM chip, an abstraction of a PWM
drivers/pwm/Kconfig line 26
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drivers/pwm/Kconfig +10
-0+ controller, that supports one or more PWM devices. Client + drivers can request PWM devices and use the generic framework + to configure as well as enable and disable them. + + The new generic framework replaces the legacy PWM framework + which allows only a single driver implementing the required + API. Not all legacy implementations have been ported to the + new framework yet. The new framework provides an API that is + backward compatible with the legacy framework so that existing + client drivers continue to work as expected.
Instead of writing "[Tt]he new framework", write "[Tt]his framework". In 4 years, this will no longer be so new. And when the next framework comes along, this will look like it is referencing the new one instead of itself.