Am Mittwoch, 9. Januar 2008 21:36:20 schrieb Alan Stern: > On Wed, 9 Jan 2008, Oliver Neukum wrote: > > > Am Mittwoch, 9. Januar 2008 18:22:51 schrieb Alan Stern: > > > On Wed, 9 Jan 2008, Oliver Neukum wrote: > > > > > > > This has an interesting implication. As the storage driver can share > > > > a device with in principle any other usb driver, we must audit all usb > > > > drivers if we wish to adopt this patch. > > > > All a device's interfaces must be resumed when the storage interface > > > > is resumed. To resume a storage device no memory must be allocated > > > > because that could deadlock. > > > > > > Maybe people shouldn't enable autosuspend for their swap device... > > > > Good advice, but not sufficient to avoid this problem. The vm may write > > out normal dirty cached pages to scsi devices, which affects storage. > > For now, I think the best approach is "head-in-the-sand". There aren't > a lot of USB storage devices partnered with other functions at the > moment. Very well with exception of the hub driver. > But it might be a good idea for all USB drivers to use GFP_NOIO in > their resume pathways. Yes, we should make this a requirement for every driver henceforth changed to support autosuspend. Regards Oliver - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
