Messages in this thread | | | Date | Thu, 10 Oct 2013 09:52:57 +0800 | From | Aaron Lu <> | Subject | Re: block layer runtime pm and udisks |
| |
On 10/10/2013 09:40 AM, Phillip Susi wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA512 > > I have been trying out the new block layer runtime pm, and run into a > problem: udisks keeps waking up the disk. Every 10 minutes it tries > to poll the SMART status of the drive, but it does first issue an ata > CHECK POWER command to see if it is in standby, and skips the check to > avoid waking the disk. The problem with runtime pm is that *any* > request brings the drive out of suspend, and the suspend wake path > forces the drive to spin up by issuing a verify command on sector 0. > > Is there a reason that the wakeup path forces the drive to spin up, or > could this be removed and rely on the drive waking up automatically if > the request requires it? > > Or would it be possible to notice that the command being sent is a > check power command, and fake the reply instead of resuming the device? > > Or does udisks just need to check the runtime pm status before trying > the check power command?
I think the udisks can be modified to check if the drive is runtime suspended and if so, avoid poll the SMART status.
Thanks, Aaron
> > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.14 (GNU/Linux) > Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ > > iQEcBAEBCgAGBQJSVgWPAAoJEJrBOlT6nu75k/cH+gMAb9YtMS21rEt94umJpBYj > BcNoyGoK39tAKZHW7pXfP2hRIm1+kPTPi44Wp7kQHu7m6BSp4YetmDkqjNv+6yAy > 8SUvPcqRsJVbF1oBXN09phBEnk/JfxqID7n6hB1lT6NqYV72VVVUEUOlnSnpHtDJ > gszV+TLH37uhd5/KiDFja3J2bJC0R/klzDF1x1clc53tGJd1NZ+h9tZZBLszIdnS > EnjukLA02Q7ooq+445WyWth2cypTXKfRbigZW+FfCI3hfAKOShVevodlGmmrQb7Z > 0xzhSoO5JTpNqJPLaNL3+JZFdXwANd+7PuO9v2XVKKUkydQ9+Vl4CfydSFhqo5U= > =iuSZ > -----END PGP SIGNATURE----- >
| |