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

From: Alan Stern
Date: Mon Jun 17 2013 - 16:24:08 EST


On Mon, 17 Jun 2013, 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)

If you don't mind a little more bike-shedding, I suggest formatting the
return value and time in a shorter format, like this:

[ 545.987650] usb 1-1: End : type pm ops @ 68, parent: usb1 -> 0, 2184 us

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/