Re: [PATCHv v3] power: Include additional information in pm_print_times

From: Rafael J. Wysocki
Date: Sun Jun 23 2013 - 07:27:30 EST


On Saturday, June 22, 2013 12:58:28 AM Shuah Khan wrote:
> On 06/21/2013 06:15 PM, Rafael J. Wysocki wrote:
> > On Monday, June 17, 2013 01:36:35 PM Shuah Khan wrote:
> >> Change __device_suspend() path to include driver name and the ops that
> >> get run for a device. This additional information helps associate the
> >> driver and the type of pm_ops the device uses in the suspend path very
> >> quickly, which will aid in debugging problems in suspend and resume paths.
> >> Changed both start and end debug messages to include pm_ops information
> >> and use dev_info() instead of pr_info(). Changed the end message to include
> >> parent device information and have the same format as the start message.
> >>
> >> dmesg output before the change:
> >>
> >> [ 164.390032] calling 1-1+ @ 69, parent: usb1
> >> [ 164.390035] call 1-1+ returned 0 after 0 usecs
> >>
> >> [ 164.390352] calling 00:0a+ @ 2457, parent: pnp0
> >> [ 164.390357] call 00:0a+ returned 0 after 3 usecs
> >>
> >> [ 164.390361] calling 00:09+ @ 2457, parent: pnp0
> >> [ 164.496458] call 00:09+ returned 0 after 103500 usecs
> >>
> >> [ 164.496494] calling 00:05+ @ 2457, parent: pnp0
> >> [ 164.496511] call 00:05+ returned 0 after 14 usecs
> >>
> >> dmesg output after the change:
> >>
> >> [ 545.985394] usb 1-1: Start: type pm ops @ 68, parent: usb1
> >> [ 545.987650] usb 1-1: End : type pm ops @ 68, parent: usb1 time(2184 usecs) err(0)
> >>
> >> [ 545.982544] system 00:0a: Start: legacy bus pm ops @ 2391, parent: pnp0
> >> [ 545.982554] system 00:0a: End : legacy bus pm ops @ 2391, parent: pnp0 time(4 usecs) err(0)
> >>
> >> [ 545.982569] tpm_tis 00:09: Start: legacy bus pm ops @ 2391, parent: pnp0
> >> [ 546.087017] tpm_tis 00:09: End : legacy bus pm ops @ 2391, parent: pnp0 time(101936 usecs) err(0)
> >>
> >> [ 546.087069] rtc_cmos 00:05: Start: legacy bus pm ops @ 2391, parent: pnp0
> >> [ 546.087084] rtc_cmos 00:05: End : legacy bus pm ops @ 2391, parent: pnp0 time(11 usecs) err(0)
> >>
> >
> > I was about to apply your patch, but then I noticed something that might cause
> > problems to happen.
> >
> > Namely, there are tools that use these messages to create suspend/resume time
> > charts and they will stop working after the proposed changes.
> >
> > Please keep the existing formatting the way it is and only append the additional
> > information at the end of each line.
> >
> > Thanks,
> > Rafael
> >
>
> Hi Rafael,

Hi,

> Yes changing the format would cause problems for scripts that rely on
> the exact format. Would you like to pick the v2 version of the patch
> that appends the additional information at the end, instead of changing
> the format? Here is the link. If you would like me to resend it, I can
> do that.
>
> https://lkml.org/lkml/2013/6/14/448

Well, this one replaces pr_info() with dev_info() and the format changes
as a result. Please keep the existing format as is literally and append any
new information to the end of the line.

Thanks,
Rafael


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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