From: joelf@ti•com (Joel Fernandes)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v4] ARM: omap: edma: add suspend suspend/resume hooks
Date: Wed, 6 Nov 2013 11:36:32 -0600 [thread overview]
Message-ID: <527A7E20.4040107@ti.com> (raw)
In-Reply-To: <CANacCWz_ahKaACbAHuue1XwaN3gutBA7Z6W+=zWBn8LvLwDM5w@mail.gmail.com>
Hi Vaibhav,
On 10/31/2013 05:25 PM, Vaibhav Bedia wrote:
> Hi Daniel,
>
> On Wed, Oct 30, 2013 at 4:21 PM, Daniel Mack <zonque@gmail•com> wrote:
> [...]
>> +
>> +static SIMPLE_DEV_PM_OPS(edma_pm_ops, edma_pm_suspend, edma_pm_resume);
>> +
>> static struct platform_driver edma_driver = {
>> .driver = {
>> .name = "edma",
>> + .pm = &edma_pm_ops,
>> .of_match_table = edma_of_ids,
>> },
>
> A while back we discovered a nasty race condition here that had us move the EDMA
> PM callbacks to the noirq phase. IIRC the MMC driver was resuming
> before the EDMA
> driver had a chance to run and that was leading to a deadlock. I am
> not sure how to force
> this scenario but i do remember spending time debugging this on a
> random codebase.
> Maybe some else has some better ideas on how to force this race condition...
I think you're talking about the patch at [1] which is not upstream. A quick
question with my limited knowledge of suspend/resume- How can there be pending
I/O operations between suspend/resume cycles? The sync is done before suspend,
so I don't understand how one is receiving a response from the card after resume
before EDMA can resume? I'd imagine that until all devices are resumed, there
will be no I/O operation issued. Let me know your thoughts.
thanks,
-Joel
[1]
https://www.gitorious.org/x0148406-public/linux-kernel/commit/b81bf04091986fa3893f31955564594567be3b61
next prev parent reply other threads:[~2013-11-06 17:36 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-30 20:21 [PATCH v4] ARM: omap: edma: add suspend suspend/resume hooks Daniel Mack
2013-10-31 22:25 ` Vaibhav Bedia
2013-11-06 17:36 ` Joel Fernandes [this message]
2013-11-07 13:30 ` Gururaja Hebbar
2013-11-07 13:32 ` Daniel Mack
2013-11-07 15:18 ` Nishanth Menon
2013-11-07 15:36 ` Daniel Mack
2013-11-07 15:48 ` Nishanth Menon
2013-11-07 20:42 ` Vaibhav Bedia
2013-11-15 14:39 ` Nishanth Menon
2013-11-17 22:09 ` Daniel Mack
2013-11-07 20:34 ` Vaibhav Bedia
2013-11-07 15:34 ` Nishanth Menon
2013-11-07 16:27 ` Grygorii Strashko
2013-11-07 20:46 ` Vaibhav Bedia
2013-11-07 16:34 ` Joel Fernandes
2013-11-07 16:49 ` Joel Fernandes
2013-11-07 17:37 ` Daniel Mack
2013-11-07 21:39 ` Joel Fernandes
2013-11-08 4:07 ` Gururaja Hebbar
2013-11-08 7:51 ` Daniel Mack
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