From: nm@ti•com (Nishanth Menon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCHv3 8/9] ARM: OMAP2+: AM33XX: Basic suspend resume support
Date: Wed, 7 Aug 2013 14:16:11 -0500 [thread overview]
Message-ID: <52029CFB.3060808@ti.com> (raw)
In-Reply-To: <52028E15.7080207@ti.com>
On 08/07/2013 01:12 PM, Dave Gerlach wrote:
> On 08/07/2013 11:22 AM, Nishanth Menon wrote:
>> On 08/06/2013 12:49 PM, Dave Gerlach wrote:
>> [...]
>>
>>> +
>>> +struct forced_standby_module am33xx_mod[] = {
>>> + {.oh_name = "usb_otg_hs"},
>>> + {.oh_name = "tptc0"},
>>> + {.oh_name = "tptc1"},
>>> + {.oh_name = "tptc2"},
>>> + {.oh_name = "cpgmac0"},
>>> +};
>>> +
>> [...]
>>> +
>>> +static int am33xx_pm_suspend(void)
>>> +{
>>> + int i, j, ret = 0;
>>> +
>>> + int status = 0;
>>> + struct platform_device *pdev;
>>> + struct omap_device *od;
>>> +
>>> + /*
>>> + * By default the following IPs do not have MSTANDBY asserted
>>> + * which is necessary for PER domain transition. If the drivers
>>> + * are not compiled into the kernel HWMOD code will not change the
>>> + * state of the IPs if the IP was not never enabled. To ensure
>>> + * that there no issues with or without the drivers being compiled
>>> + * in the kernel, we forcefully put these IPs to idle.
>>> + */
>>> + for (i = 0; i < ARRAY_SIZE(am33xx_mod); i++) {
>>> + pdev = to_platform_device(am33xx_mod[i].dev);
>>> + od = to_omap_device(pdev);
>>> + if (od->_driver_status != BUS_NOTIFY_BOUND_DRIVER) {
>>> + omap_device_enable_hwmods(od);
>>> + omap_device_idle_hwmods(od);
>>> + }
>>> + }
>>
>> Sorry, I dont like this one bit. this is the job of the suspend / resume
>> handler dealing with the specific device. I recollect having a similar
>> issue on OMAP5 where without USB driver, USB wont idle, hence we cant
>> suspend either. is the solution to do a custom handling for specific
>> nodes as above? is it even necessary - considering that in multiple
>> suspend-resume iterations, do we need to "enable and idle" multiple
>> times? Cant we do it just in hwmod/omap_device level where unbound
>> devices are disabled? Is there absolutely no possible way to do this in
>> a generic manner?
>>
>
> The issue here is that during a low-power transition the peripheral
> power domain loses context so the MSTANDBY config gets lost which is why
> the custom handling is needed on every cycle if there is no driver to
> handle it. I was unable to come up with a more generic way to handle
> this but I am certainly open for suggestions.
>
If the dts entry for device status = "disabled" you should not have
these even registered right? kinda makes me wonder if M3 could do
something about it -> since they are minimal?
When they are not,
I think the generic omap_device_pm_domain ops does not apply for these
devices due to the quirks?
Making a flag for these improper devices should let omap_device
abstraction setup different pm_domain configuration also shut them up at
boot as well (if un-bound). that will let a generic device solution
scale out to more SoCs without custom handling, perhaps?
just an quick idea - not sure about validity about the approach without
digging in more.
usually, we try to ensure system is exactly the same state as it entered
-> so at boot, we shut down everything, on wakeup, if unexpected things
like these are present, we shut them down again (in .finish handler).
--
Regards,
Nishanth Menon
next prev parent reply other threads:[~2013-08-07 19:16 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-06 17:49 [PATCHv3 0/9] ARM: OMAP2+: AM33XX: Add suspend-resume support Dave Gerlach
2013-08-06 17:49 ` [PATCHv3 1/9] memory: emif: Move EMIF register defines to include/linux/ Dave Gerlach
2013-08-08 0:48 ` Russ Dill
2013-08-08 13:35 ` Santosh Shilimkar
2013-08-12 19:32 ` Greg Kroah-Hartman
2013-08-12 19:33 ` Santosh Shilimkar
2013-08-06 17:49 ` [PATCHv3 2/9] ARM: OMAP2+: AM33XX: control: Add some control module registers and APIs Dave Gerlach
2013-08-08 0:52 ` Russ Dill
2013-08-08 13:44 ` Santosh Shilimkar
2013-08-08 16:16 ` Dave Gerlach
2013-08-09 5:11 ` Tony Lindgren
2013-08-09 20:55 ` Dave Gerlach
2013-08-12 7:54 ` Tony Lindgren
2013-08-12 19:17 ` Kevin Hilman
2013-08-12 21:40 ` Dave Gerlach
2013-08-13 14:29 ` Kevin Hilman
2013-08-13 15:08 ` Santosh Shilimkar
2013-08-13 16:19 ` Kevin Hilman
2013-08-13 18:18 ` Santosh Shilimkar
2013-08-13 18:30 ` Russ Dill
2013-08-13 18:40 ` Santosh Shilimkar
2013-08-13 19:11 ` Kevin Hilman
2013-08-14 17:27 ` Suman Anna
2013-08-14 19:16 ` Russ Dill
2013-08-20 23:39 ` Paul Walmsley
2013-08-21 17:32 ` Suman Anna
2013-08-06 17:49 ` [PATCHv3 3/9] ARM: OMAP: DTB: Update IRQ data for WKUP_M3 Dave Gerlach
2013-08-08 0:53 ` Russ Dill
2013-08-08 13:46 ` Santosh Shilimkar
2013-08-06 17:49 ` [PATCHv3 4/9] ARM: OMAP2+: AM33XX: Reserve memory to comply with EMIF spec Dave Gerlach
2013-08-08 2:30 ` Russ Dill
2013-08-08 14:19 ` Santosh Shilimkar
2013-08-08 18:16 ` Kevin Hilman
2013-08-08 19:31 ` Santosh Shilimkar
2013-08-08 20:05 ` Kevin Hilman
2013-08-08 20:11 ` Santosh Shilimkar
2013-08-09 15:11 ` Kevin Hilman
2013-08-09 16:25 ` Dave Gerlach
2013-08-06 17:49 ` [PATCHv3 5/9] ARM: OMAP2+: AM33XX: Add assembly code for PM operations Dave Gerlach
2013-08-08 7:02 ` Russ Dill
2013-08-08 14:50 ` Santosh Shilimkar
2013-08-08 15:16 ` Russ Dill
2013-08-08 15:22 ` Santosh Shilimkar
2013-08-08 16:03 ` Russ Dill
2013-08-19 12:54 ` Gururaja Hebbar
2013-08-19 17:51 ` Dave Gerlach
2013-08-06 17:49 ` [PATCHv3 6/9] ARM: OMAP2+: timer: Add suspend-resume callbacks for clkevent device Dave Gerlach
2013-08-08 7:03 ` Russ Dill
2013-08-08 14:23 ` Santosh Shilimkar
2013-08-08 16:09 ` Dave Gerlach
2013-08-08 18:25 ` Kevin Hilman
2013-08-08 19:49 ` Dave Gerlach
2013-08-06 17:49 ` [PATCHv3 7/9] ARM: OMAP: omap_device: Add APIs to enable and idle hwmods Dave Gerlach
2013-08-08 7:05 ` Russ Dill
2013-08-08 14:26 ` Santosh Shilimkar
2013-08-06 17:49 ` [PATCHv3 8/9] ARM: OMAP2+: AM33XX: Basic suspend resume support Dave Gerlach
2013-08-07 16:22 ` Nishanth Menon
2013-08-07 18:12 ` Dave Gerlach
2013-08-07 19:16 ` Nishanth Menon [this message]
2013-08-08 8:45 ` Russ Dill
2013-08-08 12:26 ` Nishanth Menon
2013-08-08 15:03 ` Santosh Shilimkar
2013-08-08 16:06 ` Dave Gerlach
2013-08-08 16:22 ` Nishanth Menon
2013-08-08 21:14 ` Kevin Hilman
2013-08-08 21:32 ` Nishanth Menon
2013-08-08 23:04 ` Kevin Hilman
2013-08-09 15:11 ` Nishanth Menon
2013-08-09 16:12 ` Kevin Hilman
2013-08-09 16:36 ` Nishanth Menon
2013-08-09 20:34 ` Kevin Hilman
2013-08-09 21:35 ` Nishanth Menon
2013-08-09 22:28 ` Russ Dill
2013-08-12 16:09 ` Kevin Hilman
2013-08-30 17:29 ` Vaibhav Bedia
2013-08-20 22:48 ` Paul Walmsley
2013-08-23 14:56 ` Dave Gerlach
2013-08-13 7:43 ` Russ Dill
2013-08-13 14:59 ` Kevin Hilman
2013-08-27 21:45 ` Kevin Hilman
2013-08-29 21:41 ` Dave Gerlach
2013-08-29 22:02 ` Kevin Hilman
2013-08-30 17:39 ` Vaibhav Bedia
2013-08-30 21:18 ` Kevin Hilman
2013-08-06 17:49 ` [PATCHv3 9/9] ARM: OMAP2+: AM33XX: Hookup AM33XX PM code into OMAP builds Dave Gerlach
2013-08-08 8:47 ` Russ Dill
2013-08-08 14:53 ` Santosh Shilimkar
2013-08-08 13:31 ` [PATCHv3 0/9] ARM: OMAP2+: AM33XX: Add suspend-resume support Santosh Shilimkar
2013-08-11 11:53 ` Daniel Mack
2013-08-12 18:59 ` Dave Gerlach
2013-08-13 12:39 ` Daniel Mack
2013-08-13 15:33 ` Dave Gerlach
2013-08-13 15:51 ` Daniel Mack
2013-08-19 9:23 ` Gururaja Hebbar
2013-08-19 17:47 ` Dave Gerlach
2013-08-27 20:23 ` Kevin Hilman
2013-08-29 21:30 ` Dave Gerlach
2013-08-29 21:52 ` Kevin Hilman
2013-08-29 22:20 ` Dave Gerlach
2013-08-29 22:20 ` Kevin Hilman
2013-08-29 22:43 ` Russ Dill
2013-08-29 23:02 ` Kevin Hilman
2013-09-03 17:24 ` Dave Gerlach
2013-09-04 15:01 ` Kevin Hilman
2013-09-04 15:12 ` Russ Dill
2013-09-04 15:18 ` Kevin Hilman
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