Re: Future of resource framework?
On Thu, Jun 3, 2010 at 8:01 PM, Gadiyar, Anand gadi...@ti.com wrote: Kevin Hilman wrote: Mike Chan m...@android.com writes: On Fri, May 21, 2010 at 9:47 AM, Kevin Hilman khil...@deeprootsystems.com wrote: Mike Chan m...@android.com writes: I'm not sure if this has been discussed, yet but since it seems that the resource framework will not be making it upstream, I am curious what are the replacements under consideration. I am starting to see similar issues on other platforms (msm / tegra) so more generic (non-omap) solution might be something to consider. Hi Mike, Which parts of the SRF do you currently use and find useful? It would be helpful for us to to understand the parts you see as useful and potentially helpful to generalize. Off the top of my head, for Droid specifically, OPP values are useful, although in theory if you changed OPP requests to cpu throughput that might give the equivalent functionality. Memory bus speeds / bandwidth, although its tied to CPU, which ultimately ends up in a cpu speed bump. Although most of the usage I've seen are just hacks, ie: the driver knows it needs 550mhz from the cpu so it will request some bogus value. As you know, the current implementation has a several layers and attempts to manage several things: OPPs, latencies etc. Our current plans are essentially to break up the one framework to rule them all philosophy and design of SRF and manage the various pieces by exending other layers such as the new OPP layer and voltage layers. Latencies are being managed by the omap_device layer and we will hopefully have some discussions with the broader linux-pm community about generalizing that more into the generic driver model over this year. Bus speed is a common resource I see for omap / msm / tegra. Clocks for devices also. ie: If I'm doing heavy mem operation and need max memory bus, I might need to request higher performance. (which might mean 600mhz on omap34030, on msm it might mean AXI clock running at 128mhz, and something else on tegra). Or if I'm doing graphics, I may need to up the gfx clock rate, or swich which pll its sourcing etc.. etc.. It doesn't look like pm qos has bus support, or even clock support, and this gets tricky if you want something semi-general. What we're hoping to work towards (and has come up in the suspend blocker related discussions) is moving towards a way to track per-device (or per-subsystem) constraints like latency and throughput in real world terms (usecs, bytes/sec, etc.) that would be general way. These constraints would then be visible to the bus- or platform-specific code that could make intelligent decisions with them (i.e whether or not to raise/lower OPP or bus speed, or whether or not to power down a powerdomain etc.) What if a driver knows that it cannot afford to let the PM layer turn off the power domain at certain points of time (maybe as long as a USB cable is connected). How can this be specified in terms of a latency or throughput constraint? Are there cases for this in omap? From what I've seen with omap3430 (atleast our hw configuration for Droid) we haven't run into this case. If you want to prevent a particular domain from entering RET or OFF, I believe you'd have to look at the latency values in the cpuidle34xx.c (or whatever it maybe called in .35) and match those latency in your driver against the PM_QOS_CPU_DMA_LATENCY. The omap cpuidle registers a table of various cpu states, which are a combination of ON, RET and OFF for various domains. (Note only handles a few domains so maybe you need to extend the table or rev a new constraint type or something to pm_qos). It seems kind of hacky and not very general, but I've only seen a need for something like this on msm7k / msm8k, and the need was an msm specific driver and have not yet seen a need for this on omap[3403] or tegra but things could change. -- Mike Just curious, since I don't understand current OMAP3 PM code as well as I would like to. - Anand -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Future of resource framework?
On Fri, Jun 04, 2010 at 05:01:49AM +0200, ext Gadiyar, Anand wrote: What if a driver knows that it cannot afford to let the PM layer turn off the power domain at certain points of time (maybe as long as a USB cable is connected). How can this be specified in terms of a latency or throughput constraint? Just curious, since I don't understand current OMAP3 PM code as well as I would like to. that should be simple if you set latency to 10us or mpu frequency to 500MHz should do it. -- balbi DefectiveByDesign.org -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: Future of resource framework?
-Original Message- From: linux-omap-ow...@vger.kernel.org [mailto:linux-omap-ow...@vger.kernel.org] On Behalf Of Mike Chan Sent: Tuesday, June 08, 2010 1:00 AM To: Gadiyar, Anand Cc: Kevin Hilman; linux-omap@vger.kernel.org; Paul Walmsley Subject: Re: Future of resource framework? On Thu, Jun 3, 2010 at 8:01 PM, Gadiyar, Anand gadi...@ti.com wrote: Kevin Hilman wrote: Mike Chan m...@android.com writes: On Fri, May 21, 2010 at 9:47 AM, Kevin Hilman khil...@deeprootsystems.com wrote: Mike Chan m...@android.com writes: I'm not sure if this has been discussed, yet but since it seems that the resource framework will not be making it upstream, I am curious what are the replacements under consideration. I am starting to see similar issues on other platforms (msm / tegra) so more generic (non-omap) solution might be something to consider. Hi Mike, Which parts of the SRF do you currently use and find useful? It would be helpful for us to to understand the parts you see as useful and potentially helpful to generalize. Off the top of my head, for Droid specifically, OPP values are useful, although in theory if you changed OPP requests to cpu throughput that might give the equivalent functionality. Memory bus speeds / bandwidth, although its tied to CPU, which ultimately ends up in a cpu speed bump. Although most of the usage I've seen are just hacks, ie: the driver knows it needs 550mhz from the cpu so it will request some bogus value. As you know, the current implementation has a several layers and attempts to manage several things: OPPs, latencies etc. Our current plans are essentially to break up the one framework to rule them all philosophy and design of SRF and manage the various pieces by exending other layers such as the new OPP layer and voltage layers. Latencies are being managed by the omap_device layer and we will hopefully have some discussions with the broader linux-pm community about generalizing that more into the generic driver model over this year. Bus speed is a common resource I see for omap / msm / tegra. Clocks for devices also. ie: If I'm doing heavy mem operation and need max memory bus, I might need to request higher performance. (which might mean 600mhz on omap34030, on msm it might mean AXI clock running at 128mhz, and something else on tegra). Or if I'm doing graphics, I may need to up the gfx clock rate, or swich which pll its sourcing etc.. etc.. It doesn't look like pm qos has bus support, or even clock support, and this gets tricky if you want something semi-general. What we're hoping to work towards (and has come up in the suspend blocker related discussions) is moving towards a way to track per-device (or per-subsystem) constraints like latency and throughput in real world terms (usecs, bytes/sec, etc.) that would be general way. These constraints would then be visible to the bus- or platform-specific code that could make intelligent decisions with them (i.e whether or not to raise/lower OPP or bus speed, or whether or not to power down a powerdomain etc.) What if a driver knows that it cannot afford to let the PM layer turn off the power domain at certain points of time (maybe as long as a USB cable is connected). How can this be specified in terms of a latency or throughput constraint? Are there cases for this in omap? From what I've seen with omap3430 (atleast our hw configuration for Droid) we haven't run into this case. If you want to prevent a particular domain from entering RET or OFF, I believe you'd have to look at the latency values in the cpuidle34xx.c (or whatever it maybe called in .35) and match those latency in your driver against the PM_QOS_CPU_DMA_LATENCY. The omap cpuidle registers a table of various cpu states, which are a combination of ON, RET and OFF for various domains. (Note only handles a few domains so maybe you need to extend the table or rev a new constraint type or something to pm_qos). It seems kind of hacky and not very general, but I've only seen a need for something like this on msm7k / msm8k, and the need was an msm specific driver and have not yet seen a need for this on omap[3403] or tegra but things could change. PM_QOS takes care of interrupt and dma latencies which today in OMAP boils down to MPU and Core power domain states. But this will not take care of other individual power domains. For preventing other power domains from entering low power states, there are power domain constraint in the SRF which again takes latencies and converts them into power domain states. But, yes if you want to prevent power domains from entering low power states for Non-latency reasons like hw bug etc there is no clean solution. You ll have to have a hack and use a dummy latency value and achieve the same. Regards Thara -- Mike Just curious, since I don't understand current OMAP3 PM code as well as I would
RE: Future of resource framework?
-Original Message- From: linux-omap-ow...@vger.kernel.org [mailto:linux-omap-ow...@vger.kernel.org] On Behalf Of Gadiyar, Anand Sent: Friday, June 04, 2010 8:32 AM To: Kevin Hilman; Mike Chan Cc: linux-omap@vger.kernel.org; Paul Walmsley Subject: RE: Future of resource framework? Kevin Hilman wrote: Mike Chan m...@android.com writes: On Fri, May 21, 2010 at 9:47 AM, Kevin Hilman khil...@deeprootsystems.com wrote: Mike Chan m...@android.com writes: I'm not sure if this has been discussed, yet but since it seems that the resource framework will not be making it upstream, I am curious what are the replacements under consideration. I am starting to see similar issues on other platforms (msm / tegra) so more generic (non-omap) solution might be something to consider. Hi Mike, Which parts of the SRF do you currently use and find useful? It would be helpful for us to to understand the parts you see as useful and potentially helpful to generalize. Off the top of my head, for Droid specifically, OPP values are useful, although in theory if you changed OPP requests to cpu throughput that might give the equivalent functionality. Memory bus speeds / bandwidth, although its tied to CPU, which ultimately ends up in a cpu speed bump. Although most of the usage I've seen are just hacks, ie: the driver knows it needs 550mhz from the cpu so it will request some bogus value. As you know, the current implementation has a several layers and attempts to manage several things: OPPs, latencies etc. Our current plans are essentially to break up the one framework to rule them all philosophy and design of SRF and manage the various pieces by exending other layers such as the new OPP layer and voltage layers. Latencies are being managed by the omap_device layer and we will hopefully have some discussions with the broader linux-pm community about generalizing that more into the generic driver model over this year. Bus speed is a common resource I see for omap / msm / tegra. Clocks for devices also. ie: If I'm doing heavy mem operation and need max memory bus, I might need to request higher performance. (which might mean 600mhz on omap34030, on msm it might mean AXI clock running at 128mhz, and something else on tegra). Or if I'm doing graphics, I may need to up the gfx clock rate, or swich which pll its sourcing etc.. etc.. It doesn't look like pm qos has bus support, or even clock support, and this gets tricky if you want something semi-general. What we're hoping to work towards (and has come up in the suspend blocker related discussions) is moving towards a way to track per-device (or per-subsystem) constraints like latency and throughput in real world terms (usecs, bytes/sec, etc.) that would be general way. These constraints would then be visible to the bus- or platform-specific code that could make intelligent decisions with them (i.e whether or not to raise/lower OPP or bus speed, or whether or not to power down a powerdomain etc.) What if a driver knows that it cannot afford to let the PM layer turn off the power domain at certain points of time (maybe as long as a USB cable is connected). How can this be specified in terms of a latency or throughput constraint? Just curious, since I don't understand current OMAP3 PM code as well as I would like to. Latency should internally map to a power domain state for the power domain associated with the device. And the SRF/new replacement fmwk should take care of taking requests from all devices associated with a power domain and programming the power domain to hit the accepted low power state. Regards Thara -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: Future of resource framework?
From: Gopinath, Thara Sent: Friday, June 04, 2010 4:20 PM To: Gadiyar, Anand; Kevin Hilman; Mike Chan Cc: linux-omap@vger.kernel.org; Paul Walmsley Subject: RE: Future of resource framework? -Original Message- From: linux-omap-ow...@vger.kernel.org [mailto:linux-omap-ow...@vger.kernel.org] On Behalf Of Gadiyar, Anand Sent: Friday, June 04, 2010 8:32 AM To: Kevin Hilman; Mike Chan Cc: linux-omap@vger.kernel.org; Paul Walmsley Subject: RE: Future of resource framework? Kevin Hilman wrote: Mike Chan m...@android.com writes: On Fri, May 21, 2010 at 9:47 AM, Kevin Hilman khil...@deeprootsystems.com wrote: Mike Chan m...@android.com writes: I'm not sure if this has been discussed, yet but since it seems that the resource framework will not be making it upstream, I am curious what are the replacements under consideration. I am starting to see similar issues on other platforms (msm / tegra) so more generic (non-omap) solution might be something to consider. Hi Mike, Which parts of the SRF do you currently use and find useful? It would be helpful for us to to understand the parts you see as useful and potentially helpful to generalize. Off the top of my head, for Droid specifically, OPP values are useful, although in theory if you changed OPP requests to cpu throughput that might give the equivalent functionality. Memory bus speeds / bandwidth, although its tied to CPU, which ultimately ends up in a cpu speed bump. Although most of the usage I've seen are just hacks, ie: the driver knows it needs 550mhz from the cpu so it will request some bogus value. As you know, the current implementation has a several layers and attempts to manage several things: OPPs, latencies etc. Our current plans are essentially to break up the one framework to rule them all philosophy and design of SRF and manage the various pieces by exending other layers such as the new OPP layer and voltage layers. Latencies are being managed by the omap_device layer and we will hopefully have some discussions with the broader linux-pm community about generalizing that more into the generic driver model over this year. Bus speed is a common resource I see for omap / msm / tegra. Clocks for devices also. ie: If I'm doing heavy mem operation and need max memory bus, I might need to request higher performance. (which might mean 600mhz on omap34030, on msm it might mean AXI clock running at 128mhz, and something else on tegra). Or if I'm doing graphics, I may need to up the gfx clock rate, or swich which pll its sourcing etc.. etc.. It doesn't look like pm qos has bus support, or even clock support, and this gets tricky if you want something semi-general. What we're hoping to work towards (and has come up in the suspend blocker related discussions) is moving towards a way to track per-device (or per-subsystem) constraints like latency and throughput in real world terms (usecs, bytes/sec, etc.) that would be general way. These constraints would then be visible to the bus- or platform-specific code that could make intelligent decisions with them (i.e whether or not to raise/lower OPP or bus speed, or whether or not to power down a powerdomain etc.) What if a driver knows that it cannot afford to let the PM layer turn off the power domain at certain points of time (maybe as long as a USB cable is connected). How can this be specified in terms of a latency or throughput constraint? Just curious, since I don't understand current OMAP3 PM code as well as I would like to. Latency should internally map to a power domain state for the power domain associated with the device. And the SRF/new replacement fmwk should take care of taking requests from all devices associated with a power domain and programming the power domain to hit the accepted low power state. Sure. But how do I pick a latency number, when that's not quite what the driver wants. The driver wants to prevent loss of hardware context - which is a different real world term than latency. - Anand -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Future of resource framework?
On Fri, May 21, 2010 at 9:47 AM, Kevin Hilman khil...@deeprootsystems.com wrote: Mike Chan m...@android.com writes: I'm not sure if this has been discussed, yet but since it seems that the resource framework will not be making it upstream, I am curious what are the replacements under consideration. I am starting to see similar issues on other platforms (msm / tegra) so more generic (non-omap) solution might be something to consider. Hi Mike, Which parts of the SRF do you currently use and find useful? It would be helpful for us to to understand the parts you see as useful and potentially helpful to generalize. Off the top of my head, for Droid specifically, OPP values are useful, although in theory if you changed OPP requests to cpu throughput that might give the equivalent functionality. Memory bus speeds / bandwidth, although its tied to CPU, which ultimately ends up in a cpu speed bump. Although most of the usage I've seen are just hacks, ie: the driver knows it needs 550mhz from the cpu so it will request some bogus value. As you know, the current implementation has a several layers and attempts to manage several things: OPPs, latencies etc. Our current plans are essentially to break up the one framework to rule them all philosophy and design of SRF and manage the various pieces by exending other layers such as the new OPP layer and voltage layers. Latencies are being managed by the omap_device layer and we will hopefully have some discussions with the broader linux-pm community about generalizing that more into the generic driver model over this year. Bus speed is a common resource I see for omap / msm / tegra. Clocks for devices also. ie: If I'm doing heavy mem operation and need max memory bus, I might need to request higher performance. (which might mean 600mhz on omap34030, on msm it might mean AXI clock running at 128mhz, and something else on tegra). Or if I'm doing graphics, I may need to up the gfx clock rate, or swich which pll its sourcing etc.. etc.. It doesn't look like pm qos has bus support, or even clock support, and this gets tricky if you want something semi-general. -- Mike For the OPP management parts, you should expect RFC patches in the next week or two that will start discussions on this. Thanks for the input, Kevin -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Future of resource framework?
Mike Chan m...@android.com writes: On Fri, May 21, 2010 at 9:47 AM, Kevin Hilman khil...@deeprootsystems.com wrote: Mike Chan m...@android.com writes: I'm not sure if this has been discussed, yet but since it seems that the resource framework will not be making it upstream, I am curious what are the replacements under consideration. I am starting to see similar issues on other platforms (msm / tegra) so more generic (non-omap) solution might be something to consider. Hi Mike, Which parts of the SRF do you currently use and find useful? It would be helpful for us to to understand the parts you see as useful and potentially helpful to generalize. Off the top of my head, for Droid specifically, OPP values are useful, although in theory if you changed OPP requests to cpu throughput that might give the equivalent functionality. Memory bus speeds / bandwidth, although its tied to CPU, which ultimately ends up in a cpu speed bump. Although most of the usage I've seen are just hacks, ie: the driver knows it needs 550mhz from the cpu so it will request some bogus value. As you know, the current implementation has a several layers and attempts to manage several things: OPPs, latencies etc. Our current plans are essentially to break up the one framework to rule them all philosophy and design of SRF and manage the various pieces by exending other layers such as the new OPP layer and voltage layers. Latencies are being managed by the omap_device layer and we will hopefully have some discussions with the broader linux-pm community about generalizing that more into the generic driver model over this year. Bus speed is a common resource I see for omap / msm / tegra. Clocks for devices also. ie: If I'm doing heavy mem operation and need max memory bus, I might need to request higher performance. (which might mean 600mhz on omap34030, on msm it might mean AXI clock running at 128mhz, and something else on tegra). Or if I'm doing graphics, I may need to up the gfx clock rate, or swich which pll its sourcing etc.. etc.. It doesn't look like pm qos has bus support, or even clock support, and this gets tricky if you want something semi-general. What we're hoping to work towards (and has come up in the suspend blocker related discussions) is moving towards a way to track per-device (or per-subsystem) constraints like latency and throughput in real world terms (usecs, bytes/sec, etc.) that would be general way. These constraints would then be visible to the bus- or platform-specific code that could make intelligent decisions with them (i.e whether or not to raise/lower OPP or bus speed, or whether or not to power down a powerdomain etc.) That's the pie-in-the-sky future I'm hoping for, and I hope to get some broader discussions around this going at some conferences this later year (LinuxCon in Aug, Plumbers in Nov, etc.) We had some early discussions in this direction at ELC already, but it needs some more thought and discussion. Kevin -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Future of resource framework?
On Thu, Jun 3, 2010 at 4:52 PM, Kevin Hilman khil...@deeprootsystems.com wrote: Mike Chan m...@android.com writes: On Fri, May 21, 2010 at 9:47 AM, Kevin Hilman khil...@deeprootsystems.com wrote: Mike Chan m...@android.com writes: I'm not sure if this has been discussed, yet but since it seems that the resource framework will not be making it upstream, I am curious what are the replacements under consideration. I am starting to see similar issues on other platforms (msm / tegra) so more generic (non-omap) solution might be something to consider. Hi Mike, Which parts of the SRF do you currently use and find useful? It would be helpful for us to to understand the parts you see as useful and potentially helpful to generalize. Off the top of my head, for Droid specifically, OPP values are useful, although in theory if you changed OPP requests to cpu throughput that might give the equivalent functionality. Memory bus speeds / bandwidth, although its tied to CPU, which ultimately ends up in a cpu speed bump. Although most of the usage I've seen are just hacks, ie: the driver knows it needs 550mhz from the cpu so it will request some bogus value. As you know, the current implementation has a several layers and attempts to manage several things: OPPs, latencies etc. Our current plans are essentially to break up the one framework to rule them all philosophy and design of SRF and manage the various pieces by exending other layers such as the new OPP layer and voltage layers. Latencies are being managed by the omap_device layer and we will hopefully have some discussions with the broader linux-pm community about generalizing that more into the generic driver model over this year. Bus speed is a common resource I see for omap / msm / tegra. Clocks for devices also. ie: If I'm doing heavy mem operation and need max memory bus, I might need to request higher performance. (which might mean 600mhz on omap34030, on msm it might mean AXI clock running at 128mhz, and something else on tegra). Or if I'm doing graphics, I may need to up the gfx clock rate, or swich which pll its sourcing etc.. etc.. It doesn't look like pm qos has bus support, or even clock support, and this gets tricky if you want something semi-general. What we're hoping to work towards (and has come up in the suspend blocker related discussions) is moving towards a way to track per-device (or per-subsystem) constraints like latency and throughput in real world terms (usecs, bytes/sec, etc.) that would be general way. These constraints would then be visible to the bus- or platform-specific code that could make intelligent decisions with them (i.e whether or not to raise/lower OPP or bus speed, or whether or not to power down a powerdomain etc.) I saw a little bit on lkml / linux-pm but I may have missed some of the threads. I'm assuming these changes you're talking about are going to be an extension to pm qos. That's the pie-in-the-sky future I'm hoping for, and I hope to get some broader discussions around this going at some conferences this later year (LinuxCon in Aug, Plumbers in Nov, etc.) We had some early discussions in this direction at ELC already, but it needs some more thought and discussion. I think for OMAP we will be ok with the existing / incremental changes to the SRF. Your overview of the pie-in-the-sky might be promising but I'm not sure how timely things will happen. I suppose I should track linux-pm more closely, I'd rather not do a bunch of throw-away work on pm qos. -- Mike Kevin -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: Future of resource framework?
Kevin Hilman wrote: Mike Chan m...@android.com writes: On Fri, May 21, 2010 at 9:47 AM, Kevin Hilman khil...@deeprootsystems.com wrote: Mike Chan m...@android.com writes: I'm not sure if this has been discussed, yet but since it seems that the resource framework will not be making it upstream, I am curious what are the replacements under consideration. I am starting to see similar issues on other platforms (msm / tegra) so more generic (non-omap) solution might be something to consider. Hi Mike, Which parts of the SRF do you currently use and find useful? It would be helpful for us to to understand the parts you see as useful and potentially helpful to generalize. Off the top of my head, for Droid specifically, OPP values are useful, although in theory if you changed OPP requests to cpu throughput that might give the equivalent functionality. Memory bus speeds / bandwidth, although its tied to CPU, which ultimately ends up in a cpu speed bump. Although most of the usage I've seen are just hacks, ie: the driver knows it needs 550mhz from the cpu so it will request some bogus value. As you know, the current implementation has a several layers and attempts to manage several things: OPPs, latencies etc. Our current plans are essentially to break up the one framework to rule them all philosophy and design of SRF and manage the various pieces by exending other layers such as the new OPP layer and voltage layers. Latencies are being managed by the omap_device layer and we will hopefully have some discussions with the broader linux-pm community about generalizing that more into the generic driver model over this year. Bus speed is a common resource I see for omap / msm / tegra. Clocks for devices also. ie: If I'm doing heavy mem operation and need max memory bus, I might need to request higher performance. (which might mean 600mhz on omap34030, on msm it might mean AXI clock running at 128mhz, and something else on tegra). Or if I'm doing graphics, I may need to up the gfx clock rate, or swich which pll its sourcing etc.. etc.. It doesn't look like pm qos has bus support, or even clock support, and this gets tricky if you want something semi-general. What we're hoping to work towards (and has come up in the suspend blocker related discussions) is moving towards a way to track per-device (or per-subsystem) constraints like latency and throughput in real world terms (usecs, bytes/sec, etc.) that would be general way. These constraints would then be visible to the bus- or platform-specific code that could make intelligent decisions with them (i.e whether or not to raise/lower OPP or bus speed, or whether or not to power down a powerdomain etc.) What if a driver knows that it cannot afford to let the PM layer turn off the power domain at certain points of time (maybe as long as a USB cable is connected). How can this be specified in terms of a latency or throughput constraint? Just curious, since I don't understand current OMAP3 PM code as well as I would like to. - Anand -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Future of resource framework?
Mike Chan m...@android.com writes: I'm not sure if this has been discussed, yet but since it seems that the resource framework will not be making it upstream, I am curious what are the replacements under consideration. I am starting to see similar issues on other platforms (msm / tegra) so more generic (non-omap) solution might be something to consider. Hi Mike, Which parts of the SRF do you currently use and find useful? It would be helpful for us to to understand the parts you see as useful and potentially helpful to generalize. As you know, the current implementation has a several layers and attempts to manage several things: OPPs, latencies etc. Our current plans are essentially to break up the one framework to rule them all philosophy and design of SRF and manage the various pieces by exending other layers such as the new OPP layer and voltage layers. Latencies are being managed by the omap_device layer and we will hopefully have some discussions with the broader linux-pm community about generalizing that more into the generic driver model over this year. For the OPP management parts, you should expect RFC patches in the next week or two that will start discussions on this. Thanks for the input, Kevin -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Future of resource framework?
Mike Chan had written, on 05/20/2010 05:37 PM, the following: I'm not sure if this has been discussed, yet but since it seems that the resource framework will not be making it upstream, I am curious http://marc.info/?l=linux-omapm=127206504624556w=2 (we are getting to the one month expiry date btw..) what are the replacements under consideration. I am starting to see similar issues on other platforms (msm / tegra) so more generic (non-omap) solution might be something to consider. I know of one by Sanjeev Premi: [1] http://marc.info/?l=linux-omapm=125716806431649w=2 it should be rather trivial to adapt it to opp layer and make it work. -- Regards, Nishanth Menon -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
