Re: [PATCH v13 1/9] scsi: sr: support runtime pm

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi Aaron,

On Mon, Jan 21, 2013 at 7:14 PM, Aaron Lu <aaron.lu@xxxxxxxxx> wrote:
> On Mon, Jan 21, 2013 at 02:31:50PM +1100, Julian Calaby wrote:
>> Hi Alan,
>>
>> On Sun, Jan 20, 2013 at 5:46 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>> > On Sat, 19 Jan 2013, Aaron Lu wrote:
>> >> > closed.  Do we want to drop support for that kind of behavior?
>> >>
>> >> I don't think we should drop such support.
>> >> And the safest way to avoid such break is we refine the suspend
>> >> condition for ODD, and using what ZPODD defined condition isn't that
>> >> bad to me:
>> >> - for tray type, no media inside and tray close;
>> >> - for slot type, no media inside.
>> >> While whether tray is closed or not may not be that important, but at
>> >> least we should make sure there is no media inside.
>> >>
>> >> Thoughts?
>> >
>> > That sounds reasonable to me, at least as a first step.  If people want
>> > their CD drive to suspend, they can eject the disc.
>>
>> Stupid question: does the kernel know if a CD has audio tracks?
>
> Yes, cdrom module knows that, but the block driver(e.g. sr) doesn't.
> See cdrom_count_tracks in cdrom.c.
>
> May I know if you have an use case that you want to runtime suspend the
> cd drive with a disc inside? That would help us to refine the runtime
> suspend condition.

The discussion seemed to be restricting when the drive would be
suspended to only occasions where the drive is empty and, where
applicable, closed. I'll admit that I hadn't followed the discussion
enough to know what the restrictions were before that, but this seemed
to be a further restriction, therefore I assumed that you were
originally planning to be able to suspend the drive with a disk
inside.

I asked my question in the hope of someone setting up the compromise:
"we could suspend the drive only if the drive is empty and closed, or
a data disc is inside and nobody's using it."

Personally, providing nobody's using it, and relevant state is stored,
I can't see any reason why you can't suspend a drive with a disc in
it.

Thanks,

-- 
Julian Calaby

Email: julian.calaby@xxxxxxxxx
Profile: http://www.google.com/profiles/julian.calaby/
.Plan: http://sites.google.com/site/juliancalaby/
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Filesystems]     [Linux SCSI]     [Linux RAID]     [Git]     [Kernel Newbies]     [Linux Newbie]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Samba]     [Device Mapper]

  Powered by Linux