Messages in this thread Patch in this message | | | Date | Fri, 21 Apr 2006 21:44:59 +0100 (BST) | From | Hugh Dickins <> | Subject | Re: sata suspend resume ... |
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On Fri, 21 Apr 2006, Pavel Machek wrote: > > Not sure why it needs time. Waiting for disk to spin up?
I don't know, and can't hear, but doubt it (I can't see why it'd need disk spun up just to do an ata_dev_set_xfermode).
> Will it recover from the timeout?
No, after that wait for 30 seconds, it degenerates into attempting I/O, getting errors, remounting the root readonly, can't get much further.
> Would sticking ata_set_mode() at the end of timeout routine help?
Well, moving the ata_set_mode after the ata_start_drive does help: then the ata_start_drive times out and fails, but that does not seem to matter at all, and the ata_set_mode then succeeds and all is well. I guess that amounts to what you meant; but all the same, I won't be alone in preferring to wait 2 seconds than 30 seconds!
But you've made me try a bit harder, and the patch below, waiting for ATA_BUSY to clear, copying a line used in several other places there, fixes it in a much more satisfactory way than mdelay(2000). (I checked how long it in fact was waiting, saw various waits between 0.8s and 1.3s).
This is a patch I'd not be ashamed to send Jeff Garzik cc linux-ide, even if we can't name precisely why it's ATA_BUSY then. But I'll give it a day or so of real-life suspend/resuming first - Arkadiusz and I both noticed we're more likely to resume successfully after a brief suspend, so longer suspends are needed for proper testing.
Hugh
--- 2.6.17-rc2/drivers/scsi/libata-core.c 2006-04-19 09:14:11.000000000 +0100 +++ linux/drivers/scsi/libata-core.c 2006-04-21 20:55:48.000000000 +0100 @@ -4288,6 +4288,7 @@ int ata_device_resume(struct ata_port *a { if (ap->flags & ATA_FLAG_SUSPENDED) { ap->flags &= ~ATA_FLAG_SUSPENDED; + ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT); ata_set_mode(ap); } if (!ata_dev_present(dev)) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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